RGB LED Driver Circuit

The following image displays a normal 3 watt RGB LED.

Based on the datasheet of this LED the three leads on each side correspond with the three leads on the other side on a straight line such that the two straight ends left to right form the terminals of the red, green, blue LEDs embossed respectively inside the package.


RGB LED 3 watt

For that reason, the top most left, right end to end leads could form the cathode, anode of the red LED, the center left, right leads could correspond to the green LED, and likewise the lower most left, right end to end leads could suggest the terminals for the blue LED.

RGB LED 3 watt

Configuring these kind of leads of this RGB LED such that the individual colors could be realigned one at a time, is definitely not hard.

The idea is simply to integrate three distinct adaptable voltage regulators with the three LEDs, as an illustration by applying a LM317 voltage regulator, as proven in this article diagram.

RGB 3 watt LED color mixer, controller circuit making use of IC LM317

RGB 3 watt LED color mixer, controller circuit using IC LM317


Speaking about the above diagram one can possibly consider that the three LM317 voltage regulators find themselves in basic fact specifically alike with their part and wiring configuration.

All of the devices include the function of voltage adjustment and are all current controlled by means of a BC547 transistor and a resistor Rc.

The leads of the 3 watt LED are associated individually to the outputs of the 3 LM317 circuits, although the input is provided to all of the the 3 devices by way of a basic DC source which might be a SMPS adapter ranked correctly for utilizing the RGB illumination.

The anode, cathode orientation of the LED is furthermore suggested in the diagram which need to be cautiously and appropriately set before attaching them to the 317 outputs.

The moment it is all totally performed, as well as the power is activated, the voltage control feature present in the LM317 devices can be employed for starting the illumination levels of the particular LEDs discretely for developing any of the stipulated color effects, beginning with the primary RGB to voilet, indigo, orange, maroon etc.

The 10K presets of the 317 circuit may be replaced with 10K pots for allowing an external control for the needed color mixing impact on the LED.

The value of Rc could be measured by applying the following formula:

Rc = 0.6/LED current rating