Im trying to do a Dimmer for leds, so far I found this site and I hope you can help me with this matter.
I make a circuit on AC power line with OSTAR leds and is working fine and my next goal is to control the light intensity with a dimmer, I bought one in store but when I put it trough is blinking at max intensity, why is this? is there other form to regulate the intensity of light? The dimmer I bought is from LUMITRON 600W slide single pole for incandescent/halogen lights.
I might be wrong here and audioguru knows more in his pinki finger then I do in my entier body about electronics BUT. I don't know why it wouldn't work. If you were using super high power spot lights (over 600W) then I can see you burning out the dimmer. However, you are using low power LEDs so you'd never get near 600W. The only thing I don't know (this might be why Guru said not it wont work) is how a triac control would work with a set of LEDs.. I've never built a circuit like that.
I made a dimmer once out of a PWM circuit... Didn't work all that great but that is all the experience I have with it! I'm sure there are simple circuits out there on the net that don't use a dimmer pack that would work.
Dimmers work by chopping parts of the AC wave out. Your LEDs flicker at about 60Hz so when you start loosing parts of the wave, the flicker slows down. Because LEDs switch at much higher speeds then a filament, you see the blinking.
You need to simply reduce the AC voltage into the LEDs, or run it from DC using PWM to dim.
I had an electronics kit that I thought used some sort of circuit similar to the one in the dimmer pack. I must be mistaken... The circuit I built a long time ago sucked for dimming my LED's anyway hah... I tried using an old L-pad for speakers but I don't think it worked either (I probably burned it out a long time ago). I was reading a while ago that there are some ICs that can handle all of that for you... I just can't remember where I saw it.
Edited by - cyclopsitis on Oct 04 2008 10:32:07 PM
You can waste power by using a huge variable resistor or transistor to dim LEDs.
Or you can use Pulse-Width-Modulation at a high frequency so you don't see the LEDs flickering. PWM has a transistor or Mosfet turning on and off. the duty-cycle creates a reduced average voltage and current. Then the transistor or Mosfet doesn't waste power by getting hot. But the LED gets a reduced average power which dims it.
Dimmer for leds
Posted - Oct 01 2008 : 2:20:28 PM
