SIMPLE DRIVER FOR A POWERFUL LED

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Probably everyone, even a beginner amateur, 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. The resistor is aliexpress.
2. The microcircuit - LM317 - aliexpress.

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 range of power 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 - LM317 linear regulator.

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