Jun 30, 2020 · In this tutorial, we are going to make a simple LED driver circuit. This circuit is used to drive different kinds of high-power LEDs of different watts. This is a simple DIY project using an LM317T IC and a few passive components.

Constant-current LED Driver Using the LM317-N You could connect the output of this to a series of LEDs (with the other terminal connected to ground) to create a very simple LED driver architecture.

Jul 25, 2015 · I came across this simple LED Driver circuit ( I am aware of the power losses but just wanted to understand its working) . Now in a Voltage regulator configuration , ADJ is connected to a voltage divider which sets the voltage output at the OUT pin .

Apr 19, 2012 · So I'm planning to use a LM317 regulator to provide a constant current supply to a high power LED (3.8v 700mA) from a 12v supply, by using an adjustment resistor of 1.8ohms (if my understanding is correct?).

Oct 2, 2009 · The LM317 in this configuration is a constant current device, it will deliver the exact current the LED is rated for (with appropriate selection of the resistor), the LED dropping voltage is irrelevant as long as the power supply voltage exceeds the LED Vf by 3V or more.

May 7, 2024 · Learn how to make an LM317 precision current regulator circuit. Example shown to drive LED using LM317 currrent limiter.

See LM317 Constant Current Source for Lighting LEDs. Fig. 2. LM317 driving three high-power white LEDs at 120mA. One can vary VIN from 15 to 35 volts and IOUT will stay a constant 120mA. Fig. 3. In Fig 3 the current has dropped below 120mA due to VIN of 12-volts - too two close to the output voltage for the load. In general VIN > Vload + 5V.

If you're wanting to use the LM317 you could simply replace one (or even both) of the adjustment resistors with a digital potentiometer. These are little chips that emulate a pot but are linked to an MCU through such things as SPI or I²C for the MCU to control the resistance.

The LM317 is very easy to use in a constant current mode. It will always strive to keep its output voltage at exactly 1.25V above whatever voltage the Adj (adjust) pin is at. The LED we are going to use is a 1W white light LED.

Apr 19, 2022 · LM317 is a three-terminal voltage regulator IC, with a high output current value of 1.5A. The LM317 IC has many features such as current limiting, thermal protection, and safe operating area protection. It can also provide a float function for high voltage uses.