----- Original Message ----- From: "yamanoor sairam" To: "Microcontroller discussion list - Public." Sent: Friday, May 14, 2010 12:49 PM Subject: Re: [EE] Variable AC voltage control using TRIAC ceiling fan regulator > Dear All, > > I would like to thank Michael, Oli and Russell for their contribution. I > tried replacing the BT136 TRIAC. I was able to dim a filament lamp. I > later connected the ozone generator power supply. It didn't work. I tried > connecting the filament lamp once again. Now it didnt work for the > filament lamp too. The TRIAC blew up! > > Is there any other method other than the autotransformer method to vary > the external supply voltage. > > Can I remove the track where at the DC output end and connect a > potentiometer in between? Am I prone to a potential shock hazard due to > 330V DC? > Sounds like the triac is being asked to pass too much current, so it blows. Anyway this is not the solution to your problem. The potentiometer would not be a good idea with that voltage and current, it would probably be very unsafe. Even if you could find a suitable mains rated one, it would be too inefficient anyway. Don't try this. In my view, the variable transformer would seem to me like the best choice to supply the ozone unit directly (after rectification and filtering) but without knowing more about it, I couldn't be sure that would have the desired effect either. Also, certainly from my point of view (as I don't know anything about ozone generators) it would be good to know the voltage and power rating of the ozone unit, to help judge the best solution. Also why you think reducing the input voltage will produce less ozone (rather than just stopping it from working). Are you going from the manufacturers specifications/instructions or is it just an idea of yours? What is the model of the ozone generator? Is it like this one: http://www.ozoneapplications.com/products/ozonegenerators/SR-8_ozone_generator.htm If it is, it may be the case that the ozone output cannot be adjusted at all, without modifying the unit itself. This model appears to require a pretty fixed input voltage (100-120V) and I think reducing it would probably just stop it working. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist