Multicolor led-bulb

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Dear Technical support,

Please tell me what I can skip-out of your  design RDR-195 if I only want to have an output 24DC-1A as power supply of a multicolor R,G,B-led bulb, if the main supply is a by triac controlled 95-265VAC net.

With help of a microprocessor I want to realize PWM- dimming, of the R,G,B currents through the leds.

For that purpose I have my own way to detect in each bulb, the firing angle of the main net.

So the firing angle detection is not the problem.

All I need is a constant-voltage power-supply, again in a by triac controlled net.

Please advise me too, if you already have another design that is more suitable for my application.

That’s an universal in use, from a central point dimmable  R,G,B, led- bulbs, the user can select one of the seven colors by him/her selves from outside, with a little screwdriver.

Thanks and best Regards

Laurens Fridael (Mr.)


For a pure triac-controlled dimming, you can use RDR-195 as a reference, especially for wide-range input.

However, the design needs to be updated for a 24V, 1A output.

For the PWM dimming, I can't find a reference design that is PWM and triac-controlled at the same time.

There is also no CV power supply because as the LED load is dimmed, the voltage naturally drops as well.