A simple driver for a high-power LED

Electronics / Simple circuits 116 137 13

Probably everyone, even a novice radio amateur, knows that in order to connect a regular Light-emitting diode Only one resistor is needed to the power supply. What if Light-emitting diode powerful? Watt so 10. What to do then?
I'll show you a way to make a simple driver for a powerful LED from just two components.

For the stabilizer driver we need:
1. Resistor – aliexpress.
2. Microcircuit – LM317 – aliexpress.

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

Advantages of LM317

Voltage stabilization range from 1.7 (including voltage LED – 3 V) up to 37 V. Excellent characteristic for motorists: the brightness will not fluctuate at any speed;
Output current up to 1.5, you can connect several powerful LEDs;
The stabilizer has a built-in protection system against overheating and short circuit.
The negative power of the LED in the switching circuit is taken from the power source, so when attached to the car body, the number of mounting wires is reduced, and the body can act as 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 W LED consumes 350 mA, and a 3 W LED consumes 700 mA (you can see it in the datasheet). The LM317 microcircuit has a stabilizer reference voltage of 1.25 - this number is constant. It needs to be divided by the current and you get the resistance of the resistor. That is: 1.25 / 0.7 = 1.78 Ohm. We take the current in amperes. We select the closest resistor in terms of resistance, since there are no resistors with a resistance of 1.78. We take 1.8 and assemble the circuit.

If the power of your LED exceeds 1 W, then the chip must be installed on a radiator. In general, LM317 is designed for current up to 1.5.
Our circuit can be powered with voltage from 3 to 37 volts. Agree, a solid range of nutrition is obtained. But the higher the voltage, the more the microcircuit heats up, keep this in mind.

You can include not one powerful LED in the circuit, 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 - LM317 linear regulator.

come back

Similar master classes

LED power supply from 1.5 volt battery

Powerful linear voltage stabilizer

Simple universal automatic charger

Simple regulated stabilized power supply

Powerful and inexpensive phyto-LED lamp

Simple regulated power supply using three LM317 chips

Particularly interesting

The simplest oscilloscope from a computer

Simple 12V Induction Heater

Simple antenna amplifier

Automatic 12V charger

A very simple powerful amplifier on a chip

The simplest inverter 1.5 V - 220 V

Comments (13)

#1 Valera Guests October 1, 2017 00:40
3

Thank you very much. This is so nice to read. But Light-emitting diode how to power one hundred watts? What if two or more at once?
- Answer
1. #2 feelloff Guests October 1, 2017 09:47
  11
  
  Take this diagram -
  
  Answer
2. #3 Guest Sergey Guests 7 February 2018 14:41
  0
  
  Valera, where did you see Light-emitting diode at 100W?
  
  Answer
#4 Hippopotamus Guests 23 October 2017 23:42
2

Shurik, this is not our method! This is not a driver, it is an analog current stabilizer, and at a high input voltage it is also a small stove. the drivers are built using a PWM circuit, but this is a pathetic parody with an efficiency of 0.0...
- Answer
1. #5 feelloff Guests December 14, 2017 07:36
  2
  
  The name is a simple driver. And not a complicated one with a PWM controller.
  
  Answer
#6 Guest Sergey Guests 13 December 2017 18:41
3

guys, if you are writing a circuit, you need to indicate not only the resistance but also the power of the resistor
- Answer
1. #7 feelloff Guests December 14, 2017 07:35
  3
  
  Fair point. Resistor of 1 W and higher power.
  
  Answer
#8 Hippopotamus Guests 21 January 2018 18:57
6

we must call things by their proper names. this is not a driver, it's just a way to check Light-emitting diode. LEDs are designed to increase the efficiency of the lamp, and propose a way to warm the Earth. only a pulsed current source can be called a “driver”, and what you are proposing is simply a linear current stabilizer, with an efficiency close to zero (especially when powered from a 37-volt source).
- Answer
#9 Guest vlad Guests 14 May 2018 09:41
0

Lm317 is an excellent integrated stabilizer, you just need to know how to prepare it. Conditions 2. Condition No. 1 - load current consumption should not exceed 300 ml. The spread of input and output voltage should not exceed 3 volts. And then you will be able to get a very good efficiency. I just assembled a 10W ice lamp, Lm is barely warm, and why does it heat up? It is rated at 1.5A, and my load consumes 0.288 A.
- Answer
1. #10 putnik Guests 20 August 2018 16:01
  2
  
  Before giving advice, you need to study the hardware! The offer is valid for low-power LEDs, for powerful LEDs the use of linear stabilizers is fraught with unjustified losses of electricity. And it doesn’t matter what the input-output voltage difference is, the savings from using LED instead of an incandescent lamp, it evaporates in geometric progression from the difference in this difference. The use of a driver should minimize electricity losses while maintaining operating parameters LED. You can't do it without PWM
  
  Answer
2. #11 putnik Guests 20 August 2018 16:13
  2
  
  Can you hear yourself? 0.3*3=1W! This is according to the most conservative (ideal) estimates. In fact, at least three watts are lost there, since you feel that it is heating up. Moreover, some power is released on the resistor. I'm not even talking about the mandatory good stabilization of the current through the diode, but in this circuit we don't have to talk about it. What then is the beauty of your scheme?
  
  Answer
#12 Alexander Guests June 20, 2018 06:49
0

Hello everyone) Can anyone give me some advice in this situation? I purchased LED panels. I took it for 220 volts and they received 24-30 volts, the driver is a bit expensive to buy, is it possible to do something similar for this? LED? As they say, cheap and cheerful)))
- Answer
#13 Vladimir Guests 21 February 2020 14:14
1

Current stabilization will work, but only to reduce voltage and at low efficiency. Only PWM regulators with current feedback work normally with LEDs. Everything else is collective farm.
- Answer