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Simple driver for a powerful LED

September 29, 2017 Electronics / Simple circuits 63 754 12

Probably everyone, even a novice amateur radio enthusiast, knows that in order to connect a regular LED to a power source, you need only one resistor. But what if the LED is powerful? Watt so at 10. What then?
I will show you a way to make a simple driver for a powerful LED in just two components.

For the stabilizer driver, we need:
1. Resistor - .
2. The microcircuit - LM317 - .

LM317 is a stabilizer chip. Great for designing regulated power supplies or drivers for powering LEDs, as in our case.

Advantages of LM317

The voltage stabilization range is from 1.7 (including the LED voltage - 3 V) to 37 V. An excellent characteristic for motorists: the brightness will not float at any speed;
Output current up to 1.5 can connect several powerful LEDs;
The stabilizer has a built-in system of protection against overheating and short circuit.
The negative power supply of the LED in the switching circuit is taken from the power source, therefore, when attached to the car body, the number of wiring wires is reduced, and the body can play the role of a large heat sink for the LED.

Driver circuit for high-power LED

I will connect a 3 Watt LED. As a result, we will need to calculate the resistance for our LED. A 1 Watt LED consumes 350 mA, and a 3-Watt LED uses 700 mA (can be viewed in the datasheet). The LM317 microcircuit - has a stabilizer reference voltage of 1.25 - this is a constant number. It must be divided by the current and the resistance of the resistor is obtained. That is: 1.25 / 0.7 = 1.78 Ohms. We take current in amperes. We select the nearest resistor by resistance, since there are no 1.78 resistors. We take 1.8 and collect the scheme.

If the power of your LED exceeds 1 W, then the chip must be installed on the radiator. In general, the LM317 is rated for currents up to 1.5.
You can feed our circuit voltage from 3 to 37 volts. Agree, a solid power range is obtained. But the greater the voltage, the more the chip heats up, keep this in mind.

In the circuit, you can turn on not one powerful LED, but, say, two or three. That is, this circuit can power up to 10 powerful LEDs.

On Ali Express, you can buy a ready-made stabilizer, with a variable resistor for any current - .

come back

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Comments (12)

#1 Valera Guests October 1, 2017 00:40
2

Thank you very much. It's so nice to read. But what about a hundred watts LED?
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1. #2 feelloff Guests October 1, 2017 09:47
  9
  
  Take this scheme -
  
  To answer
2. #3 Guest Sergey Guests February 7, 2018 2:41 p.m.
  0
  
  Valera, where did you see the 100W LED?
  
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#4 hippopotamus Guests October 23, 2017 11:42 p.m.
0

Shurik, this is not our method! This is not a driver, it is an analog current stabilizer, with a high input voltage it is also a small stove. drivers are built according to the PWM scheme, but this is a miserable parody with an efficiency of 0.0 ...
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1. #5 feelloff Guests December 14, 2017 07:36
  2
  
  The name is a simple driver. And not complicated with a PWM controller.
  
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#6 Guest Sergey Guests December 13, 2017 18:41
0

guys if you write a circuit you need to indicate not only the resistance but also the power of the resistor
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1. #7 feelloff Guests 14 December 2017 07:35 AM
  3
  
  Fair remark. Resistor from 1 W and above power.
  
  To answer
#8 hippopotamus Guests January 21, 2018 18:57
3

you need to call a spade a spade. it is not a driver, it is just a way to check the LED. LEDs are designed to increase the efficiency of the lamp, and a method is proposed to warm the Earth. only a pulsed current source can be called a "driver", and what you offer is just a linear current stabilizer, with an efficiency near the zero mark (especially when powered by a 37 volt source).
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#9 Guest vlad Guests May 14, 2018 09:41
0

Lm317 is an excellent integral stabilizer, you just need to be able to cook it. Condition 2. Condition No. 1 - current consumption by the load should not exceed 300 ml. The spread of input and output voltage should not exceed 3 volts. And then it will be possible to get a very good efficiency. I just collected an ice lamp at 10W, Lm is barely warm, and why it is heated, it is designed for 1.5A, and my load consumes 0.288 A.
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1. #10 putnik Guests August 20, 2018 16:01
  1
  
  Before advising, you need to study the materiel! The proposal is relevant for low-power LEDs, for high-power LEDs, the use of linear stabilizers is fraught with unjustified losses of electricity. And it doesn’t matter what input-output voltage difference, the gain in savings from the use of an LED instead of an incandescent lamp disappears exponentially from the difference of this difference. The use of the driver should minimize the loss of electricity while maintaining the operating parameters of the LED. There is no way to do without PWM
  
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2. #11 putnik Guests August 20, 2018 16:13
  1
  
  Do you hear yourself? 0.3 * 3 = 1W! this is according to the most conservative (ideal) estimates. In fact, at least three watts of it are lost, once you feel that it is warming. and even a certain power stands out on the resistor. I'm not talking about the mandatory good stabilization of the current through the diode, but in this circuit you can not talk about it. What then is the charm of your circuit ??
  
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#12 Alesander Guests June 20, 2018 06:49 AM
0

Hello) Can anyone tell me in this situation? I purchased LED panels. I took it at 220 volts and 24-30 volts came, the driver is expensive to buy, is it possible to do something like this for such an LED? As they say cheaply and angrily)))
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