Power supply for LED strip 12v by hand. Power supply circuitry for LED strips and more

As an inveterate electronics engineer, I continue to share my experience and best practices. I try to express without technical terms, so that it is clear from a child to a grandmother. On this cloudy day, we will choose the right power supply for the 12V LED strip, hereinafter abbreviated as “BP”. Of course, there is also a led tape for 24 volts, the principle of selection and calculation is the same, but the most common is 12V. Voltage 24V. used for designing high power lighting, it reduces the current used and the cross section of the wires by 2 times. LED lighting with great success is replacing the usual chandeliers and lamps. Lighting around the perimeter of the room looks modern and unusual.

1. Types of power supplies
2. Calculation of the power of the power supply for 12V
3. DIY power supply
4. Review of prices in stores

Types of power supplies

PSU with active cooling, round hole at the top

In stores, the blocks may be called "electronic transformer" in the old fashioned way. When I was young, there were no cell phones and switching power supplies on microcircuits. I and many others do not understand the modern name "driver", which is generally translated from English as "driver". It has absolutely nothing to do with electricity. In fact, the terms "power supply" and "driver" refer to different devices. The PSU is a voltage source, and the driver is a current source, such as in an LED lamp.

According to the cooling system, there are two types, with active and passive:

active cooling - a fan is installed in the case, as in a computer box. The fan allows you to reduce the dimensions of the case and increase power. But the disadvantage will be the noise from the fan, which will only increase over time. After a couple of years, the entire inside will need to be cleaned, and the fan lubricated or replaced, a large air flow brings a lot of dust. As a lover of absolute silence, I do not use such;
passive - the case is like a laptop power supply, or it is closed with a grill on top.

laptop type PSU

According to the execution are divided into several types:

body like a laptop unit, made of black plastic with a sticker with technical specifications. I think the best option;
hermetic case made of aluminum for wet rooms, not afraid of water and condensate. Well proven;
metal case with holes and a contact pad, used for dry rooms, mounted in an inaccessible place, preferably in a closed volume to protect against dust.

By functionality:

can be simple, only provide food;
more functional ones have a built-in dimmer;
the remote control of the remote control via infrared channel or radio channel can be built-in;
the most expensive ones have a dimmer and a remote control at once, this helps to get rid of the clutter of these blocks in different places.

Calculation of the power supply for 12V

Let's carry out a simple calculation for a popular LED strip on SMD 5050 3 meters long, 14.4W power and having 60 led/m.

We calculate the consumption of the entire tape, 3 meters
14.4W*3m. = 43W
We add 20% to the margin, which will go to the losses in the conductors
43W*1.2=52W
We got that the minimum power of the unit should be 52W. The nearest suitable model usually has 60W, so we choose it accordingly.

In addition to losses in the wires and in the LED strip itself, the quality of the design, circuits and components of the PSU also plays a significant role. If it is of medium cost and not of super high quality, then the indicated characteristics will be the maximum permissible, it will work unstably on them. I will give an example from practice, on a 60 W PSU. I connected tapes to 55 watts, but after 10 minutes of operation, the tape began to flash. When heated, the electrical parameters change slightly, the voltage drops. The power was a little lacking. I disassembled it and lowered the voltage from 12.5 to 11.5 V with an internal regulator. This was enough for stable and full lighting of the room.

DIY power supply

Sometimes you need to make a small one or a loggia, from the remnants of an LED strip, but you don’t want to buy at all, because of the costs that exceed the cost of the entire designed structure. The first thought comes to make an electronic transformer with your own hands. Buying from the Chinese on Aliexpress is not an option, you will have to wait a very long time for delivery. But there are more interesting options that many people forget about, but I constantly use them. I will not publish 12V circuits here, I will write about this separately and in detail.

Now many devices are powered by external 12V power supplies and have a power of 10 to 50 watts. These can be tablets, TVs, electric shavers, laptops, computers, routers and routers. Roughly speaking, 10W provides 700-800 lumens of brightness, which corresponds to the brightness of a 60W incandescent lamp. Surely a similar PSU is lying around in your pantry or garage. If you don’t have a house, ask your neighbor, he definitely has one.

You can buy a power supply very inexpensively on Avito. Many people have some kind of 12-volt power supply lying around at home, they don’t know where to put it, it’s a pity to throw it away, so they sell it through an ad. The seller does not know its real value and puts a low or average price. Since we do not buy in a store, but according to an ad, we can bargain. As a result of such auctions, I buy at a symbolic price of 50-100 rubles. It is beneficial for both, the seller got rid of unnecessary trinkets, and I bought a useful device cheaply, paid 5 times less than in a store. I think it’s more efficient to spend time searching for ads than looking for parts and soldering it yourself.

Overview of prices in stores

Even despite the global crisis and various sanctions against Russia, the Chinese continue to work properly and flood the Russian markets with their products. The cost directly depends on the quality, here the Chinese offer freedom of choice. Unless you are interested in a very high quality electronic transformer, except if you are designing lighting in a bunker in case of a nuclear conflict. If you operate at home in a heated room, and not in extreme temperature conditions, then an inexpensive Chinese block will be enough for you.

I do not advise buying from the Chinese, in half the cases they deceive and overestimate the electrical characteristics. Therefore, it is safer, faster, cheaper to buy in the nearest online store, your spent nerves and time are also worth a lot.

In order for you to have a general idea of the average price level in Russia, I have compiled a price-capacity correspondence table. Usually it is a multiple of 12, with a current of 1 Ampere, 12W is obtained. The price level will vary depending on the manufacturer and the city in which the online store is located.

Power, Watt	Conventional housing IP20, price	Sealed IP67, IP68, price	Expensive sealed
6W	190	250	300
12W	220	350	750
24W	300	500	950
36W	450	650	1200
48W	500	750	1400
60W	550	800	1600
72W	600	850	1700
80W	650	900	2000
100W	750	950	2200
120W	850	1050	2400
150W	950	1200	4000
180W	1050	1450	4400
200W	1250	1550	4600
250W	1350	1700	5000
360W	1500	1850
400W	1600	2000

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Feedback and questions, 94 comments

Max 18.04.2019
I warn you right away in electronics a complete zero, I'm trying to figure it out. There is an RGB LED strip for 132 diodes 2.5m which will be used as an active backlight for a 32″ monitor, +5V marking on the contacts on the tape, the power supply for 5V 2.5A successfully launched the tape, but it burned out safely during the setup process through AmbiBox. There is a block for + 12V 2.08A, can I use it or will I burn not only the block?
1. Expert answer 19.04.2019
  We need a more powerful unit, it is better to measure the power of the tape in all modes.
Valery 03.04.2019
Good afternoon LED strip 14.4w, 5 meters, it turns out 72 w, there is a 350 w power supply (from a PC). I heard there will be problems with the operation of the unit, from an excess of excess energy
1. Expert answer 15.04.2019
  There is no extra energy, there will just be a power reserve.
Vyacheslav 26.02.2019
Hello! I want to connect two meters of LED strip 5630 to a laptop-type power supply, 35 watts 3 Amperes. The LED strip will work for twelve hours a day, every day, will this power supply burn out in this mode of operation?
1. Expert answer 02.04.2019
  Depends on the power of the tape. The power supply margin in terms of power should be 20-30%.
Artem 26.11.2018
hello, tell me - there are 3 tapes: 1st 30 diodes / m, 2nd, 3rd each 60 diodes + 3 power supplies 3.5 A, 5.0A, 7.0A connected without hesitation through a 3-key switch to power supplies each tape and what is the result: the 3rd one works, the 2nd wire on the connector burned out, the 1st one lights up 3 diodes at different distances 1 green and 2 blue help me figure out the connection? Thank you …
1. Expert answer 03.12.2018
  Connect according to the diagram, apparently there are errors. Use thick wires to withstand 5-7 amps.
Alexander 18.11.2018
Good afternoon. The LED lamp burned out in which there are two strips of 50 cm each. 18W 50 pieces of LEDs are written on each strip. There was a small driver in the lamp, which burned out. Help with choosing a driver. As I understand it, the tape is not for 12 V. The lamp says 230V 36W. Thank you
1. Expert answer 03.12.2018
  Can't pick up. Ready-made kits of 4 rulers and a driver are on sale, I saw them for 300 rubles.
Oleg Mishugin 24.09.2018
Good afternoon
When using the Arlight LED strip with a 80W PSU, powerful interference occurs on the radio in the FM band.
What is the problem? In the power supply?
1. Expert answer 26.09.2018
  The power supply is phoning. Bring a radio receiver to it, the interference should increase.
Alexei 16.09.2018
Thank you for the previously received answer, tell me - did you mean to apply voltage to both ends (the beginning of the tape and the end), then you need to cut (separate) the tape “on the other side”, for example, after 7 meters?
And what kind of tape would you recommend, almost 15 meters long?
Is the specified transformer sufficient? Or is it not good quality...
1. Expert answer 17.09.2018
  The tape does not need to be cut. Tapes for 12 volts longer than 5 meters are not connected. It is necessary to measure the power of the tape.
Alexei 12.09.2018
Good afternoon, please tell me: we installed an LED strip, 14.5 meters, 14.4W per 1 meter, 12V, 60led / m, white - FERON and power supply Transformer, 360W - Navigator ...
Question: “The last 2 meters burn less brightly - what could be the problem?
1. Expert answer 14.09.2018
  Voltage drops towards the end of the tape, connect power at both ends.
Maksim 11.09.2018
Good afternoon. What power supply is needed for a 2.8m 60 diode / m 12V tape. How many watts and amps should be in it so that the tape does not burn out?
1. Expert answer 14.09.2018
  You need to measure the power or ask where you bought it.
Alexander 04.09.2018
Good afternoon. There is a non-sealed power supply for 240 watts. It has three pairs of outlets. Is it possible to combine these outputs into one pair so as not to pull three separate wires.
1. Expert answer 14.09.2018
  Usually they are combined, check the resistance between them with the unit turned off with a tester.
Julia 14.08.2018
Hello. I don’t understand anything about electrics) I lost my feet picking up a block for light tape. Tape SMD2835 DC 12v, 60 / m.
1. Expert answer 18.08.2018
  Tape power can be from 15 to 60 watts. If the real power is unknown to you, then you need a 12 volt and 60 watt power supply.
Novel 10.08.2018
Hello Sergey. I have a power supply for tapes 36W 12 V 3A. Is it possible to power three 10 W phytodiodes from it? There are no exact characteristics of the diodes yet, but I assume that the voltage is 7-10 V, the current is 0.75 A.
1. Expert answer 18.08.2018
  You can power up, connection diagrams are on the site.
Anton 18.03.2018
Hello,
What can happen to the tape if the driver is much more powerful.
For example. 3 m tape at 9.6 watts per meter. A 100 watt unit.
Thank you.
1. Expert answer 19.03.2018
  A miracle will happen, the tape will work even longer and better.
Beslan 21.02.2018
Good afternoon Can you please tell me where you can buy high-quality years and power supplies?
1. Expert answer 21.02.2018
Eugene. 23.12.2017
I took the tape. Smart / Addressable
144 LEDs per meter, 12V, the problem is that the seller could not name the power needed in watts. , I want to make the backlight of the monitor, someone wrote that there are 30-35 watts per meter. There is a PSU / Driver in a metal case with holes 12V-36W which is 3A, and there is also a PSU from the monitor, 12V, 4A which will be equal to 48 W.
Is it enough? 1st copy or 2nd one?
1. Expert answer 23.12.2017
  Measure the power of the tape and then select the block.
Andrey 05.12.2017
Hello! I want to power a burned-out 12-watt LED lamp (working diodes) from a computer power supply, and use it as a carrier, do I need to modify the PSU?
1. Expert answer 07.12.2017
  Feed, the main thing is that the voltage is suitable.
Konstantin 07.11.2017
Good afternoon. The question is next. I want to make ceiling lighting, the total length of the tape is 16 meters 12W 60 diodes / m. Advise a power supply that will not make noise. The store showed either with a fan or 2 blocks, but then 2 remotes and, accordingly, will not shine synchronously. Thanks a lot!
1. Expert answer 08.11.2017
  Replace the fan with a silent one, you can't hear it from the meter.
Anonymous 30.08.2017
Good afternoon
We plan to produce small lamps. LED strip 3528-60 will be used in them. Length
- 40 cm.
What is the best driver or small size transformer to use for power supply?
1. Expert answer 05.09.2017
Andrey 27.07.2017
Hello, tell me how to do it better. There is a tape which consists of three pieces of 2, 3 and 5 meters. The total length is 10m. Load per 1m 14.4W total 144W I chose a 250W transformer. But people say it won’t work and you need to take two transformers for 150 due to the fact that the tape does not have enough current. I don’t know how many amperes the tape consumes, it’s not written on the packaging, but the transformer gives out 2a. And here is the best way to buy transformer holes or you can put one.
1. Expert answer 16.08.2017
  One power supply is enough.
Valery 02.06.2017
Good afternoon There is such a question - when using 2 or more power supplies 12V 1.5A in the product - it is noticeable how different sections of the tape turn on not at one moment, but with different delays. It's not exactly pretty. And to put one powerful power supply does not work because of the limited dimensions.
1. Expert answer 08.06.2017
  Various circuitry. You will have to buy a small specialized power supply.
Sergey 13.04.2017
Hello. There are 4 tapes of 5m. They bought a PSU 360w 30A with active cooling. Too noisy. I want to return. Which passively cooled reliable one could be chosen for this configuration and where to buy? Or is it easier to change the cooler to 1000 rpm? (If so, then I suppose it is necessary, in addition to looking at the speed of the new cooler, to look also at the air flow?)
1. Expert answer 19.04.2017
  It is better to put the cooler up to 1000 rpm. I put silent Arctic Cooling F12 Silent, you can't hear them at close range at night.
Konstantin 04.03.2017
Sergey, good afternoon. There are 6 tapes with a current consumption of 2A each (the current was measured, not passport). There is a 5-channel controller (5 * 4A). Permissible power on the controller is 240 W (for 12v). I want to buy a 12V 200W PSU. I looked at what is on the market - are such PSUs all multi-channel? The output is two (+ V + V -V-V), or even three outputs (+ V + V + V -V-V-V). And the instructions say - load the outputs evenly. And I need one 12V output to immediately go to the input of the controller. Or maybe you can connect three + V into one output and three -V into one and apply to the input of the controller? Or is there a PSU with one output? What do you advise? Thank you!
1. Expert answer 10.03.2017
  At random I do not advise, depending on what filling. You can look for a PSU with one output.
Eugene 02.02.2017
Good day. In continuation of the topic.
Good afternoon. Please tell me how to check the real power consumption of the LED module? There is only mA on the tester. The package says that one module is 1.2w. 1.2/12=0.1A . I connect this LED module to the network through a transformer and insert a tester into the gap. I get readings of 0.06 A, instead of the declared 0.1A. having received readings from 3-4 types, I received an underestimated consumption of 40% for each type, from which I decided that I was measuring incorrectly, tell me the solution.
————————-
yes, I also thought that these are modules, after which I measured 4 types of modules from different suppliers and different delivery dates, and they all show readings with an underestimated factor of 40%. If you claim that I am taking measurements correctly, then at least 4 suppliers are deceiving me ((
1. Expert answer 03.02.2017
  For maximum certainty, test with a good tester. And they deceive in half of the cases, this is a feature of an unformed market. The Chinese manufacturer overestimated, they did not check in Russia.
Eugene 30.01.2017
Good afternoon. Please tell me how to check the real power consumption of the LED module? There is only mA on the tester. The package says that one module is 1.2w. 1.2/12=0.1A . I connect this LED module to the network through a transformer and insert a tester into the gap. I get readings of 0.06 A, instead of the declared 0.1A. having received readings from 3-4 types, I received an underestimated consumption of 40% for each type, from which I decided that I was measuring incorrectly, tell me the solution.
1. Expert answer 31.01.2017
  You were deceived, slipped weaker modules.
Maksim 10.01.2017
Hello, a question of the following nature: there is a ceiling chandelier with 5 lamps (the base is 40 mm discs with soldered diodes, the rest of the main characteristics are not indicated) 5w each, while all of them are “powered” by a transformer with a voltage of 42V and a current of 300ma (written on corps). At the same time, I will not say that the chandelier shone brightly on all its 25w, although the light did not look extinct. Recently, the transformer broke down (the controller flew). I decided to put more powerful on 7w with the same diameter of 40 mm (voltage 21-24V, current strength 280-300mA) and a driver for 42V and with a current strength of 900ma. In fact, initially at a voltage of 42 V and a current of 300ma, the calculated power was only 12.6w (with 5 lamps * 5W = 25W), which was naturally not enough (perhaps this was the reason for the dim light). Now it turns out the voltage of the new driver is 42 V, the current strength is 900ma and the output power is 38w, which is quite enough (with 5 lamps * 7W = 35W). So the question is, is it correct to use such a driver for such lamps?
1. Expert answer 10.01.2017
  The main thing is that the current matches.
Mmoguider 05.01.2017
But which one to choose for 12 volts or 24? Basically, there is no difference. The only difference is that the 12V tape and power supply are cheaper, plus they are more common in the distribution network. Therefore, many choose products with this particular voltage. So, with one indicator sorted out. Now we need to consider another characteristic - this is power.
1. Expert answer 07.01.2017
  When powered by 24 volts, the current will be 2 times less.
Oleg 27.12.2016
Good afternoon Ceiling lighting is made of three strips of 5m. Each on its own power supply and all this on a common switch. Two years later, the beginnings and ends of the ribbons began to turn very yellow. Why can this be?
And one more problem: one of the tapes began to be very late when turned on. Maybe in half an hour it will turn on. And then it might turn off. What could be the problem?
Thank you
1. Expert answer 27.12.2016
  Yellow because low quality LEDs have gradually changed color temperature. If the power-on is delayed, the power supply is faulty.
Dmitriy 25.12.2016
Good afternoon I want to make a backlight on the niche of the ceiling. The perimeter is 22 meters. Question - is it possible to do it with one tape? Or is it better to break it into 4 (two 4 meters each and two 7 meters each) with one transformer?
1. Expert answer 26.12.2016
  Read on my website about connecting LED strips.
Dmitriy 08.12.2016
Good afternoon There may be a somewhat amateurish question, but nevertheless: a niche in the ceiling was illuminated, 2 transformers were used, for two pieces of tape, 8 m each. Six months later, both power supplies began to chirp strongly, both transformers with passive cooling. What could be the problem and what should I replace it with? Thanks for the replies!
1. Expert answer 15.12.2016
  In power supplies, most likely the chokes began to make noise, the compound probably disappeared. They should be smeared with epoxy resin so that they do not scratch.
Vitaly 30.10.2016
Good afternoon! Please tell me there is a power supply 400w 33a. From outputs 3 - and 3+, DC + 12v MAX 150W is written on the block (as I understand it, this is a maximum of 150 watts per output) how can I get 400 watts from it
1. Expert answer 31.10.2016
  Look at the instructions for it 🙂
Andrey 24.10.2016
Good afternoon
The question is the following: is it possible to put a transformer for LED strips behind a dimmer, and will this not affect the brightness of the LED strip?.
P.S. A CD tape and 4 retro lamps (Edisson) will be connected to one wiring outlet from the ceiling. The light from them is not particularly needed, the glow of the thread is needed, therefore, instead of the switch for this ceiling outlet, it is planned to install a dimmer.
1. Expert answer 25.10.2016
  You can't do that, the power supply is not designed for this.
Garik 21.09.2016
OSRAM HALOTRONIC HTB 70/230-240, compatible with s1md 5050 3 meters, will it shine without interruption? thanks for answers
1. Expert answer 23.09.2016
  Measure the power consumption of the tape, this is the only correct option. It can be from 15W to 45W.
Vit C 21.09.2016
I decided on the power supply for the LED strip (200W). So 200W is on the low-voltage side (12V). Question - what is the power consumption of the power supply on the high-voltage side (220V)?
1. Expert answer 23.09.2016
  Efficiency is usually 80-90%, it is better to measure with a wattmeter.
Alexei 24.08.2016
Good afternoon
Made a light niche in the country
I installed SMD 5050 diodes - in 5 lines of 50 pieces each. (The declared power of each cluster is 0.9W, 240 mA)
Installed the block to it connected the block 380W 30A
After 5 minutes after turning on, it goes out, then after a minute it turns on and so on.
What's my mistake?
1. Expert answer 24.08.2016
  Don't even know. Maybe the load on the power supply is too small and it turns off the output voltage, such as standby mode.
Konstantin 23.08.2016
Sergey, good afternoon. As you suggested, I measured the LED strip current. And so, a laboratory transformer power supply 30V 5A. Tape type 5050, 60 diodes per meter. I set it to 12.2 V. The device showed consumption - 0.7 A !!!. That is, the consumption is less than 1A, and the power is 8.4 watts. And the nameplate power is 14.4 W!!! I admit that two meters can consume a little more than 8.4 * 2 = 16.8 !!! Well, how to choose a power supply?
1. Expert answer 23.08.2016
  Choose a block according to the real power of the tape with a margin of 20%. With power, you were deceived a little.
Konstantin 18.08.2016
Are you still answering? Tell me, in the country for a child in the room I want to install 6 strips of 2 meters each. Ribbon 14.4 w/m, i.e. each strip 28.8 watts. How to choose a PSU - one for everything or 6 for each lane? And the second question, maybe a little unexpected - put the switch on LED strips, that is, break the circuit to 12v or 220v, i.e. to bp? Each connection has its pros and cons. What do you recommend?
1. Expert answer 20.08.2016
  The switch is placed in front of the power supply. One block for all LED strips. First measure the real power of the tape, it can be 2-3 times lower.
Rustam 05.08.2016
Good afternoon I burned out the driver from the LED spotlight with a power of 30W. The voltage was written on the driver 16-40V. There is a driver for 48V, 33W, 700 mA available. Can this driver be connected to a spotlight? Or should the voltage be lowered to 40V? If yes, what is the best way to do it? Will the driver or spotlight burn out? Need a stabilized current or voltage? Thank you in advance for your response!
1. Expert answer 08.08.2016
  The voltage needs to be lowered. The LED works on a stabilized current.
Pauline 28.06.2016
Good afternoon I need to mount a mirror light from a 70 cm long LED strip with a power of 4.8 W/m. Then I need a 12 V power supply, with a power of 0.7 * 4.8 * 1.2 = 4.032 W? Does the current strength matter? Will a 12V 5W unit be enough for me?
1. Expert answer 28.06.2016
  The block is selected by power, suitable for 5W.
Dmitriy 08.06.2016
Good afternoon spotlight 100w jazzway burnt driver what to replace
1. Expert answer 10.06.2016
  Replace with another driver suitable for current
Anonymous 23.12.2015
Hello. There are several power supplies from phones. I would like to use them to connect LEDs with power from 1 watt to 10 watts. Of course, each power supply for individual LEDs, or a group if 1 watt. Is it possible to rework the PSU from economy lamps. Tell me how to do it. Thank you.
1. Expert answer 23.12.2015
  I use power supplies from phones as nightlights, at 20-30 Lumens.
  Calculate and measure the power of each block and select LEDs for it. You set the current and the connection scheme based on the parameters of the diode.
Alexei 10.12.2015
Sergey, thanks. As I understand it, I need a third 200W power supply. Can you draw a diagram of what it should look like?
1. Expert answer 11.12.2015
  There will be 3 blocks with an amplifier for 3 segments. Better measure the real power of the tape, suddenly deceived. Then you won't need to buy another block.
Alexei 09.12.2015
Hello. There are 3 strips of 5m each with a power of 150W each. There is 1 dimmer 4-channel (768W) at 192W each channel. There are 2 amplifiers of 360W each. And there are 2 power supplies of 200W each. Can you please tell me how to tie all this into one scheme ?! It seems that I found something similar on the Internet, but I am confused by 200W power supplies, because the total power of the tapes is 450W. Thank you.
1. Expert answer 10.12.2015
  There are wiring diagrams on the site. Power supplies must have a power reserve of 20%. Measure the actual power of the tapes.
Maksim 28.10.2015
Hello Sergey. Thanks for the helpful articles, I learned a lot, but I have a few questions:
1. Quote from the article: “PSU 60 W. I connected tapes to 55 watts, but after 10 minutes of operation, the tape began to flash. When heated, the electrical parameters change slightly, the voltage drops. The power was a little lacking. I disassembled it and lowered the voltage from 12.5 to 11.5 V with an internal regulator. As I understand it, the PSU has less than the nominal power, because of this it could not cope with the load and heated up, in connection with this, the voltage dropped? Or is the PSU itself unable to cope with its voltage of 12.5 volts and, in connection with which, it heated up and lost voltage?

2. Will the 5050 meter long LED strip and PSU work stably if I connect not 12 volts, but 9 volts and 1.6 amps? In general, it is interesting how LEDs and PSUs will behave at different values of voltage and current.
1. Expert answer 28.10.2015
  1. The block did not pull the rated power.
  2. Will work from 9V, but dimly. Experiment, lower the voltage. You can't control the current.
Dmitriy 14.10.2015
I saw on YouTube on the LOUD SOUND channel that a 4-channel amplifier was connected to a power supply from an LED strip. The current consumption of the amplifier is declared 75 amperes. Amplifier ARIA AP4.100. What power supply should I get? Perhaps two blocks will need to be taken. Will stay in the room.
1. Expert answer 14.10.2015
  The amplifier is powered by 12 volts, then a 1000 W power supply will be required if the maximum peak current is 75 amps. If the amplifier works at full capacity, the power reserve will work out the bass better, without failures. The main disadvantage of the power supply from the LED strip is that there is a lot of noise and interference at the output, which affect the sound quality. I used to collect DACs, amplifiers and speakers. I do not recommend installing two blocks, they will need to be coordinated according to the load.
Anonymous 23.09.2015
Hello! I am interested in the following question: is it possible to get by with one, but powerful power supply to connect 12 five-meter LED strips, or will I still have to take 2 PSUs?
1. Expert answer 23.09.2015
  Depends on the power of the LED strip, but you did not specify this. When installing long sections, it is more rational to use 2 power supplies, otherwise very long and thick wires will be required. In the long ones there will be voltage losses. I don’t know the installation conditions for the diode tape and the dimensions of your room, so I can’t say for sure.
Alexander 03.09.2015
Very useful information, but there is a question: is it equivalent to using a regular power supply unit from a computer, because there are loops with a 12v output and the power of the unit is quite large: 300-500 watts?
1. Expert answer 03.09.2015
  You can also use the power supply from the computer, in compliance with safety regulations. But blocks have protection, and without a minimum load, it will not start. Although the models are different, simple and complex, and the circuitry is different. I forgot to include these power supplies in the review, I hurried. The main thing is to have 12 volts stable. The only thing they have fans are noisy, someone really does not like it.
Valery 02.08.2015
Hello Sergey. Diode tape 5730, 3 strips pasted on a copper radiator, PSU from a CCTV camera. The first 3 LEDs started flashing. Can you suggest something for the repair. Thanks in advance. Valery.
1. Expert answer 02.08.2015
  SMD 5730 LEDs on the tape are connected in 3 pieces. If 3 diodes start flashing, then one of the diodes is burned out, the contact is either there or not. The problem may be overheating of one of the diodes, contact with the radiator is broken, the LED strip is peeled off somewhere.
  A section of 3 diodes can be replaced with a new one, or a faulty diode can be found and replaced with a new one.

LEDs replace such types of light sources such as fluorescent lamps and incandescent lamps. Almost every home already has LED lamps, they consume much less than their two predecessors (up to 10 times less than incandescent lamps and 2 to 5 times less than CFLs or energy-saving fluorescent lamps). In situations where a long light source is needed, or it is necessary to organize illumination of a complex shape, it comes into play.

Led strip is ideal for a number of situations, its main advantage over individual LEDs and LED arrays is the power supply. They are easier to find on sale in almost any electrical store, unlike drivers for high-power LEDs, moreover, the selection of the power supply is carried out only by power consumption, because. The vast majority of LED strips have a supply voltage of 12 volts.

While for high-power LEDs and modules, when choosing a power source, you need to look for a current source with the required power and rated current, i.e. take into account 2 parameters, which complicates the selection.

This article discusses typical power supply circuits and their components, as well as tips for repairing them for beginner radio amateurs and electricians.

Types and requirements for power supplies for LED strips and 12V led lamps

The main requirement for a power source for both LEDs and LED strips is high-quality voltage / current stabilization, regardless of mains voltage surges, as well as low output ripple.

According to the type of execution, power supplies for LED products are distinguished:

Sealed. They are more difficult to repair, the case does not always lend itself to careful disassembly, and inside it can be completely filled with sealant or compound.

Unsealed, for indoor use. Better amenable to repair, tk. the board is removed after unscrewing a few screws.

Cooling type:

Passive air. The power supply is cooled by natural air convection through the perforation of its case. The disadvantage is the inability to achieve high capacities while maintaining weight and size indicators;

Active air. The power supply is cooled by a cooler (a small fan, as installed on PC system units). This type of cooling allows you to achieve more power with a similar size with a passive power supply.

Power Supply Schemes for LED Strips

It should be understood that there is no such thing as a “power supply for an LED strip” in electronics, in principle, any power supply with a suitable voltage and current greater than that consumed by the device is suitable for any device. This means that the information described below applies to almost any power supply.

However, in everyday life it is easier to talk about the power supply according to its purpose for a particular device.

The general structure of a switching power supply

Switching power supplies (UPS) have been used to power LED strips and other equipment in recent decades. They differ from transformer ones in that they operate not at the frequency of the supply voltage (50 Hz), but at high frequencies (tens and hundreds of kilohertz).

Therefore, for its operation, a high-frequency generator is needed, in cheap and designed for low currents (units of amperes) power supplies, an autogenerator circuit is often found, it is used in:

electronic transformers;

electronic ballasts for fluorescent lamps;

mobile phone chargers;

cheap UPS for LED strips (10-20 watts) and other devices.

A diagram of such a power supply can be seen in the figure (click on the picture to enlarge):

Its structure is as follows:

Optocoupler U1 is included in the OS, with its help, a signal from the output is supplied to the power part of the oscillator and a stable output voltage is maintained. There may be no voltage in the output part due to a break in the VD8 diode, often this is the Schottky assembly, which must be replaced. Also a swollen electrolytic capacitor C10 often causes problems.

As you can see, everything works with a much smaller number of elements, the reliability is appropriate ...

More expensive and power supplies

The circuits that you will see below are often found in power supplies for LED strips, DVD players, radio tape recorders and other low-power devices (tens of watts).

Before proceeding to consider popular circuits, familiarize yourself with the structure of a switching power supply with a PWM controller.

The upper part of the circuit is responsible for filtering, rectifying and smoothing mains voltage ripples 220, essentially the same as in the previous type, and in subsequent ones.

The most interesting thing is the PWM block, the heart of any decent power supply. A PWM controller is a device that controls the duty cycle of an output signal based on a user-defined setpoint or current or voltage feedback. PWM can control both the load power using a field (bipolar, IGBT) switch, and a semiconductor controlled switch as part of a converter with a transformer or inductor.

By changing the pulse width at a given frequency, you also change the effective value of the voltage, while maintaining the amplitude, you can integrate it using C- and LC-circuits to eliminate ripples. This method is called Pulse Width Modeling, that is, modeling the signal due to the width of the pulses (duty cycle / duty cycle) at a constant frequency.

In English, this sounds like a PWM controller, or Pulse-Width Modulation controller.

The figure shows a bipolar PWM. Rectangular signals are control signals on transistors from the controller, the dotted line shows the voltage shape in the load of these keys - the effective voltage.

Higher quality power supplies of low average power are often built on integrated PWM controllers with a built-in power switch. Advantages over the autogenerator circuit:

The operating frequency of the converter does not depend on either the load or the supply voltage;

Better stabilization of output parameters;

Possibility of simpler and more reliable setting of the operating frequency at the stage of designing and upgrading the unit.

Below are several typical power supply circuits (click on the picture to enlarge):

Here RM6203 is both a controller and a key in one case.

The same, but on a different chip.

Feedback is provided using a resistor, sometimes an optocoupler connected to an input called Sense (sensor) or Feedback (feedback). Repair of such power supplies is generally similar. If all the elements are in good order, and the supply voltage is supplied to the microcircuit (leg Vdd or Vcc), then the matter is most likely in it, having more accurately viewed the signals at the output (leg drain, gate).

You can almost always replace such a controller with any analogue with a similar structure, for this you need to check the datasheet for the one installed on the board and the one you have available and solder it, observing the pinout, as shown in the following photos.

Or here is a schematic representation of the replacement of such microcircuits.

Powerful and expensive power supplies

Power supplies for LED strips, as well as some power supplies for laptops, run on a UC3842 PWM controller.

The scheme is more complex and reliable. The main power component is transistor Q2 and a transformer. When repairing, it is necessary to check the filtering electrolytic capacitors, the power switch, the Schottky diodes in the output circuits and the output LC filters, the supply voltages of the microcircuit, otherwise the diagnostic methods are similar.

However, more detailed and accurate diagnostics is possible only with the use of an oscilloscope, otherwise, check for short circuits of the board, soldering of elements and breaks are more expensive. Replacing suspicious nodes with known working ones can help.

More advanced models of power supplies for LED strips are made on the almost legendary TL494 chip (any letters with the numbers "494") or its analogue KA7500. By the way, most AT and ATX computer power supplies are built on the same controllers.

Here is a typical power supply circuit on this PWM controller (click on the diagram):

Such power supplies are highly reliable and stable.

Brief verification algorithm:

1. We power the microcircuit according to the pinout from an external power source of 12-15 volts (leg 12 is plus, and leg 7 is minus).

2. A voltage of 5 volts should appear on 14 legs, which will remain stable when the power changes, if it “floats” - a microcircuit for replacement.

3. There should be a sawtooth voltage on pin 5; you can only “see” it with an oscilloscope. If it is not there or the shape is distorted, we check the compliance with the nominal values \u200b\u200bof the timing RC circuit, which is connected to pins 5 and 6, if not, these are R39 and C35 in the diagram, they are to be replaced, if nothing has changed after that - the microcircuit is out of order.

4. Outputs 8 and 11 should have rectangular pulses, but they may not be due to the specific feedback implementation scheme (pins 1-2 and 15-16). If you turn off and connect 220 V, they will appear there for a while and the block will go into protection again - this is a sign of a working microcircuit.

5. You can check the PWM by shorting pins 4 and 7, the pulse width will increase, and by shorting pins 4 to 14, the pulses will disappear. If you get different results - the problem is in the MS.

This is the most concise test of this PWM controller; there is a whole book “Switching Power Supplies for the IBM PC” about repairing power supplies based on them.

Although it is dedicated to computer power supplies, there is a lot of useful information for any radio amateur.

Conclusion

The circuitry of power supplies for LED strips is similar to any power supplies with similar characteristics, it lends itself quite well to repair, modernization and restructuring to the required voltage, of course, within reasonable limits.

The cut end of the LED strip usually takes the form you see in the photo. The number of pads depends on the type of tape. For example, the RGB tape in the photo has four contact pads and a separate conductor must be soldered to each of them.

To obtain high-quality soldering, it is imperative to prepare the surfaces to be soldered by covering them with a layer of solder. After watching the video, you will see that tinning LED strip pads is not a difficult job.

The contact pads of the LED strip are no exception, and before soldering wires to them, they must also be tinned, as shown in the photo.

Next, you need to tin the ends of the wires. To do this, you must first cut them into pieces of the desired length and remove the insulation from the ends. The color of the insulation of the wires does not matter, it's just that when wires with different colors of insulation are used, it will not be necessary to continue to deal with their continuity with a multimeter. It is difficult to remove the insulation a couple of millimeters and tin the wires. Therefore, the insulation is removed by 8-10 mm, and after tinning the ends of the wires, they are cut with side cutters to a length of three millimeters.

Now it remains to attach the tinned ends of the wires to the contact pads and, in turn, touch each pad with a soldering iron tip with a drop of solder for a couple of seconds to get soldered, as in the photo. After soldering, you need to carefully examine whether drops of solder have touched adjacent pads. To be sure that there is no short circuit between adjacent sites, it is advisable to use a multimeter.

The voltage at the contacts of the LED strip does not exceed 24 V, so the soldering point can not be isolated. But, nevertheless, it is better to wrap it with a couple of turns of insulating tape or put on a heat shrink tube, followed by heating with a building hair dryer.

How to cut and connect pieces of LED strip

When mounting and installing an LED strip, it is often necessary to cut it into segments equal to the size of the surface on which it is glued. When organizing the illumination of a room, it is necessary to mount the tape at a right angle, both in the same plane (the corner on the ceiling) and in mutually perpendicular planes (the outer or inner corner of the walls in the room). In this case, as a rule, segments of the LED strip of insufficient length remain, and the question arises, how to connect them together correctly?

How to cut LED strip

The LED strip is thin, elastic and can be easily cut into pieces with ordinary clerical scissors. To cut the tape into pieces with skill, you need to familiarize yourself with its device and electrical circuit.

The LED strip, regardless of its length, consists of many segments connected in parallel, as in the photo. One segment of the LED strip, designed for a supply voltage of 12 V, consists of three housings with LEDs and three resistances. Each housing has three semiconductor crystals of red, green and blue glow colors. Crystals of the same glow color are connected in series, as shown in the electrical diagram. To limit the current flowing through the chains of LEDs, resistors R1-R3 are installed in series with them.

If you look at the LED strip from the side of the sticky layer with the peeled off protective film to the light, you can see the current-carrying copper tracks running along. They supply voltage along the tape to each segment.

Now you understand that the LED strip can be cut into many segments, but the cutting step must be equal to the length of one segment. Cutting is allowed in the middle of the pads, usually the place of the allowed cut is indicated by a line, sometimes a pictogram in the form of scissors is applied.

How to splice LED strip

In preparation for the installation of the LED strip, its segments of insufficient length may appear. They can be successfully spliced together without prejudice to the operation of the tape as a whole. There are two ways to splice segments of the LED strip, using the LED connector and soldering. You can also connect the tapes by soldering in two ways, directly soldering the pieces of tape together or using additional wires.

I draw your attention to the fact that it is possible to splice the LED strip only up to a length of no more than five meters. This is due to the fact that the cross section of the printed tracks on the tape is small and with a tape length of more than five meters there will be a large voltage drop on the tracks. If this requirement is violated, nothing irreparable will happen, just the LEDs at the end of the tape will not glow at full brightness.

Splicing the LED strip by soldering without wires

The technology for preparing the contact pads of the LED strip does not differ from the preparation for soldering wires to them.

The photo shows a ribbon cut with clerical scissors into two parts. Since the contact pads are not oxidized, you can immediately start coating them with solder.

The contact pads on the side of the LED installation are covered with a thick layer of solder and are ready for tape splicing.

At this stage, the preparation of the tape for solder splicing does not end. It is also necessary to cover with solder the contact pads, which are located on the side of the sticky layer. To access them, you need to peel off part of the protective film.

The contact pads that have opened to the eye must also be covered with a thick layer of solder. After that, you can start soldering segments of the LED strip. The photo shows only two contact pads, it is necessary to cover with solder the other two, hidden under the film.

A piece of tape, in which the contact pads were covered on the back side, is superimposed with an overlap of three millimeters on the tinned contacts of the second piece. Now it is enough to warm up the contact pads in turn with a soldering iron tip and the pieces of tape will become one. In the photo you see the result of my work on splicing the LED strip by soldering without wires, the soldering turned out to be perfect. To get a beautiful soldering, the main thing is not to spare rosin.

Splicing the LED strip with wires by soldering

The technology for soldering wires to the contact pads of the LED strip is given above. It remains only to demonstrate an example of this type of splicing.

For the manufacture of a jumper, a wire of any brand is suitable, the main thing is that its cross section is sufficient. Based on the fact that the current consumption of the five-meter brightest SMD5050 LED strip, which has 60 LEDs per meter of length, is 4.2 A, an insulated copper wire with a diameter of 0.8 mm is suitable for splicing any type of tape.

The wire of the required length is prepared and it remains only to tin its bare ends. The length of the jumper wire can be from one centimeter to several meters.

Due to the fact that the contacts for connecting in this type of LED strip are interconnected in pairs, for reliability, it was decided to solder the ends of the wires simultaneously to two contacts. To do this, the ends of the wires were bent at a right angle.

You can see the result of soldering wires to the contacts of the LED strip in the photo. The second end of the wire is also soldered to the second segment of the LED strip. If rosin was used as a flux for soldering, then its residues at the soldering point can not be removed, since rosin is a dielectric. Although rosin absorbs moisture, but in this case it does not play a role. To give soldering a beautiful appearance, rosin from the tape can be removed with a brush dipped in alcohol.

The segments of the LED strip are securely connected, and now it can be mounted on a plane, bending at any angle.

The LED strip must not be bent at a right angle. After installing the jumper from the flexible wire, nothing now prevents you from installing the tape under any internal or external corner of the walls.

to the power supply or controller

A powerful power supply is a metal box with perforations that serve to circulate air in order to remove heat from radio components and a terminal block with screws. To increase the efficiency of heat dissipation, an air fan is often placed inside the power supply. There is usually a plate on the case, which indicates the designation of the unit and its main technical characteristics.

Each terminal screw is always marked with a marking for the correct connection of the wires. To supply voltage to a monochrome LED strip, it is enough to solder the wires to it using the technology described above, slip them under the washers and tighten them with screws. For a more reliable connection of wires, twist the tinned ends into rings.

Scheme for connecting a monochrome LED strip to a power supply

Terminal markings indicate the following. L (phase) and N (zero) terminals for connection to mains voltage 220 V. FG – ground terminal. G, G and G - three terminals interconnected in the block for connecting the negative output (-) of the tape. Terminals V+, V+ and V+ are also interconnected in the power supply and serve to connect the positive output (+). As a rule, these symbols indicate the conclusions of other types of power supplies.

The photo shows the wiring diagram for connecting a monochrome (can only glow in one of the colors) LED strip to the power supply. As you can see, there is nothing complicated. The length of the tape should not exceed five meters. If you need to connect several tapes to the power supply, and there are only two terminals on it, then all wires of the same polarity coming from the LED strips are connected to one terminal with the appropriate marking.

When connecting a power cord with a plug, the brown and blue wires can be interchanged, since it is not known where the phase will be, and where the zero will be, it all depends on how the plug is inserted into the outlet. The green/yellow ground wire of the plug cord must be connected exclusively to the ground terminal. If there is no yellow-green wire in the cord, then the ground terminal can be left free, but this will be a violation of safety regulations. This will not affect the performance of the LED system.

Scheme of parallel connection of segments of LED strips

Sometimes there is a task of backlighting when you need to connect a lot of short LED strips to the power supply that are distant from each other, for example, when illuminating a shop window or hanging pictures at a distance from each other. In this case, there is no need to pull wires from each piece of tape to the power supply. One or more main pairs of wires are laid, to which short conductors from the ribbons are then connected.

Attaching the wires coming from the ribbons to the main wire can be done in any way. The most reliable is twisting followed by soldering, but in this case, connection using connectors or terminal blocks is preferable. This will simplify the task of repair, in case such a need arises, during the operation of the LED system.

The photo shows an example of connecting segments of an LED strip using Wago-type terminal blocks. Wires of blue and white insulation are main, single-core. The black wires go to the LED strip. If an RGB LED strip is installed, then you will need to lay four main wires and apply four Vago terminals per branch.

It should be noted that Vago terminals, depending on the type, are designed to connect wires of a certain diameter. For example, the terminals in the photo are designed to connect wires with a diameter of 0.5 to 2.5 mm. If the wire is thinner, then there will be no reliable contact, and it will simply be impossible to insert thicker than 2.5 mm. The stranded wire, before inserting it into the Vago disposable terminal, as in the photo, must be tinned so that it becomes like a single-core wire or a special tip is pressed onto it, otherwise it will be impossible to insert it into the terminal.

Sometimes it becomes necessary to place the LED strip according to a complex pattern when installing the backlight, for example, when illuminating a cabinet or a showcase. In this case, you can use the tape itself as the main wires by soldering the leads of the tape segments directly to the contacts of one of the tape segments. The total length of all segments with this method of connection should not exceed five meters.

When creating lighting with LED strip from segments of different power, they can be connected in series and in parallel in any combination. For example, connect a 12 W SMD3014 LED strip meter in series with a 4.8 W SMD3528 strip, and connect another 12 W SMD3014 strip two meters long to it. The main thing is not to forget, when switching on in series, about the limitation of the total length of 5 meters.

After developing the tape mounting scheme, it is necessary to determine the cross-section of the wire to connect it to the power supply. If the current consumed by the LED strip is not known, then it can be determined from the table based on the type of LEDs and their number installed per meter of length.

How to connect LED strip
to the power supply from the computer

The cost of powerful switching power supplies for a voltage of 12 V and 24 V, with a load current of more than 5 A, designed to power LED strips, often exceeds the cost of the strip itself.

But it is possible to completely avoid or reduce the cost of creating an LED system if you use a power supply from a desktop computer. It is not difficult to find a morally obsolete computer system unit with a working power supply in your back room, with friends or at work.

The photo shows one of a large family of power supplies taken from a desktop computer. The computer power supply is a finished product and can be successfully used to power other devices, including powering an LED strip. All power supplies have a standard range of voltages shown in the table, and differ only in the allowable load current.

Several dozen wires of different colors come out of the power source, but the same voltage is output to the wires of the same color, as shown in the table.

There is always a plate on the power source, which indicates its maximum power and the permissible load current for each voltage. Although the power supply in question is designed for a load power of 400 W, the load capacity of the +12 V circuit is only 16 A (12 V × 16 A \u003d 192 W), which is enough to power almost any LED lighting or backlight system.

How to force turn on the computer's power supply

If you plug the power cord into the socket and turn on the switch on the power supply, the unit will not start working until it receives a control signal from the motherboard, which is given when you press the "Start" button on the system unit. Therefore, to start the power supply, you need to emit a control signal from the motherboard.

To do this, it is enough to close pin 16 (POWER ON green, in some PSU models it is gray) with pin 17 (common GND black wire), as shown in the photo. If the connector has 20 contacts, then contacts 14 and 15 are closed to each other, to which wires of the same colors are connected. The contacts are located on the side of the connector retainer.

The jumper can be made from a piece of copper wire with a diameter of 1 mm, bent in the form of the letter P, as shown in the photo. Then insert into the connector pins.

If the power supply is no longer going to be used in the computer, then a more reliable wire connection can be made. To do this, you need to remove the insulation from them for a length of 1-2 cm, wrap one wire around the other with one turn and then solder it with solder. The connection can not be isolated, since it already has electrical contact with the power supply housing.

How to connect a 12 V LED strip to a computer power supply

Before installing the LED system, it is necessary to check the operability of the power supply. It is not recommended to connect impulse blocks to the network without load at the output. To do this, you need to connect a load to any of the connectors on the wires, to the contacts connected to the black and yellow wires, and apply a 220 V supply voltage to the unit. Any light bulb used in a 12 V car is well suited as a load. For example, from a headlight, having a power of about 60 W and consuming a current of about 5 A. If the light bulb shines at full brightness and the fan impellers in the power supply rotate quickly, then the unit is in order. If you have a multimeter, for complete certainty, you should measure the output voltage. If the light does not shine, then the unit is faulty and needs to be repaired. If the impeller rotates slowly or noisily, the fan must be cleaned and lubricated.

The computer power supply has the most four-pin connectors, as in the photo. It is most convenient to connect the LED strip to these wires, since they are long and if the LED system consumes a lot of current, you can connect to several connectors, or by biting off them, solder the wires going to them directly to the contact pads of the tape. To connect a 12 V LED strip, you only need yellow and black wires.

Connecting the power supply to the LED strip is best made detachable. This is useful in case of modernization or repair of the lighting system. If there is a mating part (male) for a four-pin connector, then it is enough to solder its yellow and black wires directly to the contact pads of the tape.

If there is no mating part of the standard connector, the yellow and black wires must be cut off from the connector. After that, they can be soldered to the controller connector, in case of connecting an RGB tape, use any other connector designed for the current consumption of the tape or solder directly to the pads of the tape or splice with the wires coming from the tape.

Before connecting by soldering or twisting, the wires must be stripped of insulation and tinned with solder. Next, the wires are twisted together, the protruding ends are cut off, and soldered with a drop of solder. Bare areas are closed in advance with an insulating tube put on them or covered with insulating tape.

How to connect a 24 V LED strip to a computer power supply

The technology for connecting an LED strip designed for a 24 V supply voltage does not differ from connecting a strip designed for 12 V. The only difference is in the color of the wires to which you need to connect.

There are no units in the computer that require 24 V to be powered, but there are units that require +12 V and -12 V to operate. The value of these voltages is indicated relative to the common (black) wire. Therefore, if you connect the LED strip only to the yellow and blue wires, then a voltage of 24 V will be supplied to it. The blue wire is connected only to the multi-pin connector for connecting to the motherboard. Yellow is there too.

But unfortunately, the load capacity of the –12 V voltage circuit is much lower than the load capacity of the +12 V circuit. So in the power supply shown in the photo, the load current in the +12 V circuit is 16 A, and in the circuit In only 0.5 A.

The load capacity of the power supply with this connection of the tape will be determined by the minimum current of any of the voltages. In this case, this is 0.5 A. Taking into account the fact that +3.3 V and +5 V voltages are not used, you can safely load the unit up to at least 1 A. A larger load current is quite acceptable, I suppose up to three amperes , but this needs to be verified experimentally for a specific power supply model.

About the cross section of the wires of the power supply

The diameter of the copper stranded wires coming out of the power supply is 0.8 mm (section 0.5 mm 2), which allows you to connect a load on one wire up to 3 A. If you need more current to power the tape, then you need to connect an LED strip to more wires of the same color. For example, to power the tape, you need a current of 5 A, which means you need to use two wires, and if you need a current of 15 A, then there are already five wires.

How to connect LED R G B strip to controller

R G B LED strip can be connected without a controller, directly to the power supply. With such a connection, the meaning of its use is lost, it will shine either white or one of the colors with low brightness.

The articles on the site “Connecting R G B LED Strips” and “Repairing the Lighting System with LED R G B Tape” discuss in detail the issues of connection, the principle of operation and repair of the controller, but do not cover the issue of connecting R G B tape to the controller using a detachable connection.

If wires with the mating part of the connector installed on the controller are already soldered to the tape, which is rare, then there are no questions. It is enough to articulate the connectors, taking into account the key, and the connection is ready.

I had to connect the RGB tape to the LN-IR24B controller, which has a connector, as in the photo. The pitch between the pins in the connector is 2.5 mm, the pin diameter is 0.7 mm, and the depth is 4 mm. The mating part for the connector was not available.

The connection problem can be solved in three ways. Cut off the connector and splice the wires using the shear twist method, solder the wires directly to the controller PCB, or select a suitable connector.

The best solution is not to compromise the design of the controller, as this will void the warranty, but to pick up a connector. There was a five-pin connector from the VCR board, suitable in terms of geometric parameters. After removing the excess contact, the check showed that the pins entered with a slight interference and were securely fixed in the counterpart. It remains only to solder to its pins, observing the marking of the wires coming from the LED strip. Dressed cambrics will give the soldering a finished look and protect the wires from breaking when bending.

The mounted R G B LED system is ready and can be installed on the Christmas tree, for which it was intended.

Recommendations for equipment placement and installation of LED strip

The LED system is not a system of increased reliability and therefore it is necessary to carry out the installation taking into account the possibility of its complete or partial dismantling in case of failure for repair.

The back of the LED strip is covered with a sticky layer protected by a film. To fix the LED strip on the surface, it is enough to remove the protective film and press the strip to the surface. But if the surface has a large roughness, then the tape will stick poorly and may fall off over time. For reliable fastening on a rough surface, you can first apply a strip of double-sided tape equal to the width of the tape on it, and stick the tape on it.

There are special aluminum profiles that are fixed to the wall with self-tapping screws, and the tape is already glued to the profile. A plastic diffuser is attached to the profiles, which allows you to hide the LEDs and make the luminous flux more uniform. But the cost of profiles often exceeds the cost of the line itself. A special profile can be replaced with a cheap plastic corner, fixing it to the surface with liquid nails.

When lighting ceilings, the LED strip is most conveniently hidden behind the ceiling plinth. Depending on the design, the LEDs are directed either parallel to the ceiling surface or at an angle to it. To maximize the use of the light flux and obtain uniform illumination of the ceiling, the tape must be placed at a distance of at least five centimeters from it.

When illuminating showcases, shelves or the interior of cabinets, care must be taken that the LEDs do not shine directly into people's eyes. Otherwise, the effect of highlighting will be incomplete, and possibly negative, for example, in the case of highlighting a product in a store.

High-power power supplies often have fans that emit acoustic noise during operation, which usually increases over time. This fact must be taken into account if the LED system is installed in a room where noise can become an annoying factor, for example, in a bedroom. In this case, the power supply is taken out to another room where the noise will not interfere.

It's no secret that the LED strip cannot be simply plugged into the network - it will burn out without even a second working. But then how to provide it with the necessary tension? That's what the stabilizer is for. In simple terms, this is a 12 V power supply for an LED strip, which equalizes the voltage to the required one. But today we will talk about what types they are, how they are arranged and whether it is possible to make such a stabilizing device with our own hands.

Read in the article:

12V power supply for LED strip - what does it do

The voltage regulator does the work of lowering the high mains voltage of 220, 12 or 24 V and converting AC to DC. If you figure it out, then the charger of any mobile phone performs the same actions, but it will produce less voltage.

But such stabilizers can not only produce direct current at 24 or 12 V. The power supply for a 12 V LED strip can also be a controller. Thanks to a complex electronic circuit, such power supplies control the flickering modes and color changes of the RGB strip. They are capable of delivering enough power to “light up” several separate segments of the LED strip, provided that they are properly selected and connected. But first things first. And first, let's figure out what advantages and disadvantages can be noted in the need to use such power supplies.

Pros and cons of connecting LED strips to a 12V power supply

The main positive aspect of such switching can be called electrical safety - after all, the voltage of 220 V is life-threatening, which cannot be said about 12 V. This advantage covers all minor disadvantages, such as the need to purchase a PSU for the tape and the need to hide it somewhere.

Practice shows that even insulated connections in damp rooms can break down. In the case of installing lighting in the bathroom, this is doubly true. One can imagine what will happen if the phase is on a cast-iron bath while a person is in it. Surely everyone imagines a hair dryer that has fallen into the water ... If this happens with a 12 V backlight, then the person will not feel anything but a slight tingling, which many will not even pay attention to.

Another advantage is that if the stabilization device comes with the controller, then at 12 V it turns out to be quite compact. You can imagine what size it would be at a voltage of 220 V. Thus, the conclusion suggests itself that the minor inconveniences associated with using a 12 V power supply for LED strips are more than offset by the advantages that such a connection has.

Types of stabilization devices for the light strip

LED strip power supplies can be divided into several types:

for cooling– active or passive. Active implies the presence in the PSU of a fan that forcibly cools the transformer;
for execution- it can be a closed, sealed or open case. The latter is mounted only in dry and dust-free rooms;
by functionality- an ordinary power supply unit, with a dimmer, a controller, or a combination of all these functions.

Of course, the most interesting power supply for LEDs with an RGB controller. This abbreviation in the marking of both the PSU and the light strips means that the device is multi-colored. It came from the first letters of the name of the main three colors in English, which form the remaining 4. Such controllers are most often equipped with an IR receiver to be able to control colors using a remote control. This allows you to turn the backlight on and off, as well as switch its shades from anywhere in the room.

Often a dimming function is also built into it - a slow dimming of lighting - which is also very useful.

Power supplies in a sealed case are installed in rooms with high humidity, such as a bathroom, bathroom or kitchen. At the same time, a good controller is able to switch the backlight from one line to another as needed.

It is important to know! To ensure the uninterrupted operation of the LEDs, it is necessary to choose the right power supply not only in terms of voltage, but also in terms of power. The correct connection is also very important, which we will discuss in more detail below.

How to calculate the power supply for the LED strip

Such calculations are not difficult. All that is required is to calculate the total power consumption of a strip of light, and then add a margin of 20%. For example, let's try to calculate the required power supply for LEDs. Let's take a tape with SMD3528 elements, 3 m long and with a frequency of 120 pcs/m. For such a strip, the power consumption of all diodes in a segment of 1 m will be equal to 28.8 watts. We get 28.8 × 3 + 20%, which will be equal to 100.68 watts. The closest to this indicator will be a 150 W PSU, so it will be needed. Although a 100-watt unit will work quite normally with such a band.

These calculations are very important. After all, if you do not understand how to choose a power supply and do it wrong, it can simply burn out. And this is money thrown to the wind and wasted effort on installation.

Options for connecting the LED strip to the power supply

There are only two ways to connect this lighting equipment, like any other - this is in series and in parallel. But here the installation option plays a very important role. If you choose the wrong switching method, you can burn the contact tracks through which the voltage passes from one LED to another.

The choice of mounting scheme depends on the length of the strip sections. On each of them there are places for the cut. Usually the distance between them is 3 LEDs. And if the tape segments total more than 5 meters, then it can no longer be connected in series. We will figure out how to properly install and connect.

Serial connection - in what cases it is performed

Such switching is a connection in which power enters the second consumer, passing through the first.

If the segments are short enough, then they must be connected to each other in series. This will increase the length of the strip to the required. But at the same time, it should be understood that the total final length should not exceed the same parameter of the new LED strip. In other words, if it was sold in a 5 m coil, then after splicing, the final size of the strip should be less than or equal to the original one.

If the length is exceeded, there is a danger of burning out the conductive paths between the light diodes due to the passage of high power current through them. In this case, the tracks between the first elements are burned out first. When they are removed between the next, and so on until the length of the strip is normal for proper operation.

Parallel connection of the strip and how to do it

Parallel connection is called switching, in which power from the source goes simultaneously to two or more consumers. However, they are not connected to each other.

If you want to connect the strip, for example, 9 m, then you need to install in parallel. To do this, we take segments of 5 m and 4 m. The wire leaving the power supply is switched in the same order with both bands. It turns out that power from the stabilizing device is supplied simultaneously to both segments. This allows you not to overload the tracks going from one LED to another.

It is important to know! With this installation scheme, do not forget about the operating power of the stabilizer. It consists of the total consumption of two segments.

In general, it is necessary to understand that when connected in parallel, the voltage drop remains unchanged, but the current consumption increases - this is quite important to know when installing such lighting equipment.

How hard is it to make a voltage stabilizer for a light strip

It should be noted that the assembly of such a PSU from scratch is only possible for a professional radio electronics engineer. But do not think that without a certain qualification it is impossible. After all, it is quite possible to use a factory-made transformer for this purpose. A good option would be to use a power supply from a computer. The main task here is to choose a device suitable for the LED strip in terms of power.

Before choosing a power supply for the strip, we determine the required voltage. If 12 V is needed for the diodes, then the output from the transformer should be from 12 to 20 V. It is quite convenient if you have a ready-made two semiconductor rectifier at hand, which is necessary for the stabilizer to work. And the third thing you need is a microprocessor. The most successful solution would be to use the 7812 chip.

By putting all the details together, you can get a power supply with an output current of 1.5 A, which is quite enough for an LED strip. Of course, it is unlikely that you will be able to assemble a controller for an RGB strip with your own hands, but there is a trick here. It is quite possible to use a block from an old Chinese garland, the parameters of which are indicated on the case. In this case, based on the power it gives out, you can calculate the required strip length and connect it to the controller, thus achieving the ability to switch between flicker and color modes. The only inconvenience will be that switching can only be done with a button on the block, which means that it will not be possible to hide it.

Another fairly simple way that does not require knowledge of radio electronics is to connect a light strip through a controller from an LED chandelier with a remote control. All technical data for calculating the length of the tape by power can be taken from the documentation for.

Is it possible to repair the voltage regulator for light diodes

This work is quite feasible even for home craftsmen who do not have certain skills and knowledge. The main task here is to determine which of the parts needs to be replaced. The main parts that can fail are the microprocessor and the rectifier bridge. Transformers rarely burn, but this happens. Let's try to understand how to deal with the breakdown.

It is worth starting the check with the simplest nodes, as in any equipment. Having opened the cover of the group of contacts, we set the switch of the multimeter to the position of alternating current 750 V (on some devices 1000 V) and applying power to the unit, we check whether it is supplied to the input contacts of the transformer for the 12 V LED strip.

Very important! When performing all operations with the transformer, you must be extremely careful and accurate. Do not touch live parts with unprotected parts of the body. Remember that electric shock is dangerous to life and health.

If voltage is supplied to the unit, then the supply wires are in order. We check the voltage at the output of the transformer. As already mentioned, it should be from 12 to 20 V. The next step is to check the diode bridge. To do this, set the value of the multimeter switch to a constant voltage with a value slightly higher than the output of the transformer. When touching the contacts at the output of the rectifier bridge, the device should show the same values \u200b\u200bas the previous step (only slight downward deviations are possible).

If, after performing these steps, it becomes clear that the step-down transformer and diode bridge are working properly, this means a problem in the microcircuit. After a malfunction is identified, it will be necessary to replace the failed part of the circuit. The new one should have the same parameters.

Where to buy a power supply for LED strip

You can buy the necessary equipment these days at any electrical store. Fortunately, the range of such products is now quite wide. You can also order it online. However, it is worth as carefully as possible to study the reviews of those who have already used this resource. You should especially beware of purchasing such goods on Chinese resources. Here's what one netizen has to say about it.

vitas77, Russia, Moscow: The driver went for almost three weeks, and then the day came when I found the long-awaited package in my mailbox, everything was packed quite well, the driver itself with soldered wires. I connected the LEDs, according to the description, connected the power, everything worked, but my joy did not last long, the driver warmed up noticeably and eventually refused to work. The device worked for less than an hour. Bottom line, time and money wasted. At the end of everything written, I want to warn you, before ordering, contact the seller and find out as much information as possible.

More on Otzovik: http://otzovik.com/review_2975618.html

Let's try to consider how prices differ when purchasing such power supplies in regular stores and on Internet resources. Let's start with real sellers of RGB controllers (the last digit in the model name means the number of channels).

Make and model	Total current, A	Channel current, A	Voltage, V	Number of programs	Average cost, rub.
iMLed2	30	15	5-25	23	1200
iMLed4	30	20	5-20	23	1500
iMLed6	30	15	5-25	20	1900
iMLed9	80	15	5-20	20	3000
iMLed16x3	32	2	5-23	20	3300
iMLed16	80	15	5-20	20	3500

As you can see, the cost of such devices is not too high. But what about online stores? Let's try to find devices with similar characteristics.

Make and model	Total current, A	Output power, W	Output voltage, V	Number of programs	Average cost, rub.
CRIXLED CRCN N18-RFS-12	18	216	12-24	14	1800
ASD LS-CB-12	12	144	12-24	20	500
LSC 003	2	24	12-24	No	500
LSC 008	4	144	12-24	3	1500
RGB 144W	12	144	12	14	1200
Ecola LED strip	6,6	1500	12-36	24	2000

Generally speaking, the prices do not differ too much. This means that there is no point in taking risks by buying a “pig in a poke” over the Internet. Indeed, in this case, it will not be possible to make a claim to the seller, and the guarantee, most likely, will be absent.

Finally

A power supply for an LED strip is necessary - this is clear to everyone. The main thing is to choose one that fits in all respects to your light strip. And if all the calculations are made correctly, then such a voltage stabilization device will work for quite a long time.

We hope that today's article was useful to our dear reader. In the discussions below, you can always ask questions about a topic that is not clear. Write, communicate, share your experience. And our team will try to answer your questions as fully as possible and help you as much as possible.

Finally, we suggest watching a short video on the topic.

Video: connecting LED strips

To the electrical network through a socket, to use such an accessory, an individual power supply will be required.

This is due to one single factor - the voltage that the tape uses during operation differs from the standard home voltage of 220 V.

Accordingly, if you connect it directly to a home outlet, no matter what type, it will simply disable the entire electrical network.

According to the voltage consumed, the tapes are divided into several types:

Having an operating voltage of 12 V.
Having an operating voltage of 24 V.
Having an operating voltage of 36 V.

Depending on the type of product, it will need an appropriate power supply with a power of 12 V, 24 V or 36 V. Their main purpose is to lower the voltage level to the level required by the installed one.

24 V models, although present on the market, are still very rare, the 12 V option and power supplies suitable for it individually are much more common. Tapes 36 V appeared not so long ago and so far there are no positive trends in their distribution.

Device

The most basic version of the 12 V power supply, in order to perform its primary function - voltage conversion, must have the following device:

step down, which has a suitable power for the intended purposes.
Diode bridge, which usually includes 4 LEDs identical to each other, performing the tasks of a device that changes AC voltage to DC.
Capacitor, ensuring that there are no gaps. They differ in their capacitance, and the higher this indicator, the more preferable the capacitor. Acts as a network filter and suppresses all interference that is generated in the network. If the noise level is too high, then a semiconductor element is used - a varistor.
Protective case, inside which all the listed devices that are part of the power supply are removed.

Kinds

When choosing a suitable battery for LED strips, it must be borne in mind that there are several varieties that differ in their characteristics:

Transformer blocks

The main element of the device of which is the element of the same name. The transformer in this case must be step-down in order to convert the voltage of 220 V to the desired level. The already converted voltage, necessary for the operation of the tape, is supplied to the rectifier.

The ripple voltage is applied to the mains filter capacitors and the inductor, after which it enters the stabilizing circuit. As a result, a direct current is formed at the output of the block.

The main advantage of such a mechanism over other analogues is its ability not to fail in idle mode and a simple circuit with a simple network decoupling. At the same time, it also has a number of disadvantages, such as a significant mass, low efficiency and increased sensitivity to voltage overloads.

Pulse

They also have a transformer., but due to the implementation of work at higher frequencies, this made it possible to significantly reduce its dimensions, and, consequently, its mass.

The main disadvantage of this option is that it retained another minus of the transformer option - increased sensitivity, to which was added the possibility of the device breaking down when operating in idle mode.

Power calculation

When making a purchase, you need to focus on the features and parameters of the LED strip, for which the selected power supply will be used.

The main factors influencing the choice are:

Required power.
Rated voltage.

At the same time, different tapes require a different amount of voltage that they consume, this indicator directly depends on the number of diodes mounted in them. In order to unify the corresponding calculation and make it easier, the accepted value of the nominal power of a meter tape is traditionally taken.

In order for the power source to be selected correctly, taking into account the parameters of the accessory itself, it is necessary to multiply the named nominal value and the total length of the tape in meters.

For clarity, you can consider an example with the calculation of power on any LED strip.

Assume that you have an accessory with the following characteristics:

40 diodes mounted on each meter of it.
Implementation carried out only with 5-meter reels.
Operating voltage value equals the standard value, that is, 12 V.

The nominal power value for the indicated variety is equal to the value of 4.8 W / m. Using a simple calculation method, we can get the power of the entire device: 4.8 x 5 \u003d 24 watts.

DIY power supply

tape diagram for 20 cells, for its assembly you need: a transformer for 1A, 12W; diode bridge with a capacitor; chip for the radiator (suitable 7812)

The source, to provide the device with power, does not have to be bought in a ready-made form in a store, it is quite possible to create it yourself if you follow the following algorithm of actions:

Pick up 4 diodes- absolutely any variety is suitable, since the voltage on them will be quite low.
Pick up a capacitor, there is only one requirement for it - a voltage of at least 25 V. You should not be afraid of choosing a device with a too high parameter, since when leaving the unit, the direct current always has a strictly fixed value.
Diodes twisted or soldered to each other in pairs, while it is important that the contact points have a different polarity. This is easy to determine: the side with the drawn stripe is positive, and the empty side without the stripe is negative.
Then it is necessary to connect both soldered pairs of diodes together, only now according to the opposite principle: at the point of contact, the side with the positive polarity of one element should meet with the same side of the second pair. Accordingly, on the other hand, parts of adhesions with negative polarity are connected. As a result, a small square-shaped element is obtained - this is the so-called diode bridge.
We connect 2 outputs from the transformer with a diode bridge, and the points of contact in both cases should be contacts with a combined plus or minus value, and contacts with exclusively negative or positive polarity, created at the last stage of the bridge formation, should remain free.
At this stage a capacitor is connected to the bridge. Here it is necessary to take into account that the polarity in the surge protector has a different designation: the “-” mark traditionally denotes the side with negative polarity, respectively, the side without any designations is positive. The connection to the bridge is as follows: the positive terminal of the capacitor is connected to the remaining free side with positive polarity, and the negative terminal is connected to the side of the corresponding polarity.
At this stage you will need several wires of different colors. Usually, blue is used for negative polarity, and red for positive, but this rule is not immutable, the wires can be selected at your discretion or based on what is available. If necessary, you can even use the same color for both polarities by simply making a corresponding mark on one of the wires in the form of a knot or notch.
red wire it is necessary to solder to the output of the diode bridge, which has a positive polarity, to the same place where the positive output of the network filter is located. The blue wire should also be soldered to the negative terminal of the bridge.
Basic device for a 12 V power supply, this is considered complete. If desired, you can check the voltage level. Even in the event of any errors or the appearance of too high indicators, do not worry, with a constant load, instead of idling, the device will begin to produce the voltage it is supposed to. However, those who want to achieve maximum accuracy in voltage-related parameters can equip the resulting block with an additional stabilizer.
Finished device can be removed into the case, after which it is completely ready for use.

How to choose?

A lot of important factors depend on the correct choice of power supply, including the very functioning of the LED strip and its safety.

Therefore, when making a choice, it is necessary to rely on the following rules:

Tape targeting, on which the need for protection against moisture and the tightness of the power supply will depend. For installation in bathrooms or in places where moisture can enter the device or its elements, it is necessary to choose a system with moderate protection. If the tape is supposed to be used outdoors, then a model with full protection against moisture and, accordingly, a sealed power supply are required.
Accurately determine the required power source of energy. By the way, it is this factor that largely determines the final price of the device. It is quite simple to determine the required parameter: the power consumed by the tape is multiplied by its footage, the resulting figure increases by 25%, since the block will also need a certain reserve. This calculation calculates the power that the power supply must have.
Unit operating voltage must match the same parameter of the LED strip. Although this accessory is mostly represented on the market with 12 V models, 24 V devices are rare, and more recently there have been separate tapes with an operating voltage of 36 V.

Model overview

Given the wide range of power supplies offered by the market today, and this product differs not only in varieties, but also in characteristics and manufacturers, it is very easy to get confused in it.

In order to simplify the selection process, it is proposed to pay attention to the most popular models today:

Power Supply DR-75W

Manufactured by Brille, its main purpose is to convert the voltage of 220 V to 12 V at the output, which makes it compatible with most modern models of LED strips in the home.

Among other advantages is a built-in protection system against the occurrence of possible overloads and short circuits. The housing is durable and impermeable, which provides internal protection against dust.

On average, the price for such a model is 3000-3200 rubles.

Domestic power supplies from the Mollusk series

They will become an ideal option if the LED strip is supposed to be used on the street. It was for such conditions that Mollusks were developed, so they are not only completely sealed and have maximum protection against moisture, but also very resistant to temperature changes.

For example, if the manufacturers of standard sources guarantee their operation at an ambient temperature not higher than +25-35°C, then Mollusks have raised the bar for this indicator to +40°C. All models are small in size and, if necessary, can be mounted in protective covers, which will provide an additional level of protection.

Also, they have an additional security system that reduces the likelihood of electric shock during careless use, and the standard fuses have been replaced with an electronic protection system against overloads and voltage surges.

The price for them varies in the range of 600-2500 rubles.

Power supply for LED strip 12v by hand. Power supply circuitry for LED strips and more

Types of power supplies

Calculation of the power supply for 12V

DIY power supply

Overview of prices in stores

How to cut and connect pieces of LED strip

How to cut LED strip

How to splice LED strip

Splicing the LED strip by soldering without wires

Splicing the LED strip with wires by soldering

to the power supply or controller

Scheme for connecting a monochrome LED strip to a power supply

Scheme of parallel connection of segments of LED strips

How to connect LED strip to the power supply from the computer

How to force turn on the computer's power supply

How to connect a 12 V LED strip to a computer power supply

How to connect a 24 V LED strip to a computer power supply

About the cross section of the wires of the power supply

How to connect LED R G B strip to controller

Recommendations for equipment placement and installation of LED strip

12V power supply for LED strip - what does it do

Pros and cons of connecting LED strips to a 12V power supply

Types of stabilization devices for the light strip

How to calculate the power supply for the LED strip

Options for connecting the LED strip to the power supply

Serial connection - in what cases it is performed

Parallel connection of the strip and how to do it

How hard is it to make a voltage stabilizer for a light strip

Is it possible to repair the voltage regulator for light diodes

Where to buy a power supply for LED strip

Finally

Video: connecting LED strips

Device

Kinds

Transformer blocks

Pulse

Power calculation

DIY power supply

How to choose?

Model overview

Power Supply DR-75W

Domestic power supplies from the Mollusk series

How to connect LED strip
to the power supply from the computer