To Filter or Not to Filter...

[Pine Fire]

Hello!

I'm working on a homebrew Olsen 595 dimmable controller (uses 256-step counter chips and timing oscillator) and so far it works great. But I don't know whether to put RFI filters on the outputs of the triacs. Do you guys put caps/coils on the outputs of your triacs, or is that something I even need to worry about?

Thanks in advance for the advice!

[g2ktcf]

have not seen any that require them. Of course we don't have any inductive loads.

BTW welcome to DIYC.

[Pine Fire]

Cool, thanks for the reply g2ktcf. I'll probably just go ahead and run wire from the triac straight to the light. Awesome, fewer components to purchase is always good!

The reason I asked is because when I was first playing around with light control via parallel port I was scrapping triacs from lamp dimmers (pretty laborious), and they have a choke and capacitor on the lamp output. I wasn't sure if I needed to do the same with my own light controller, and wasn't sure if the 'ringing' in the long Christmas light wiring would be enough to be an RF concern. I'm still pretty new to this light control stuff, and I don't want to inadvertently contact any aliens or get the FCC angry at me. ;)

[ErnieHorning]

If you’re using the snubberless TRIAC’s like most of us use, you probably won’t need anything even if you do control transformers. I’ve done some experiments with my Renard 64 controller and have not had any problems.

I’ve had an animated deer running for three seasons that I dim, ramp, fade and sequence just like anything else and neither the deer or the controller have had any issues.

I connected a 24 volt, 3 amps transformer to a channel and sequenced to ramp up/down fast and slow, flash at fast and slow. I ran this for a week with a 1 amp load and another week with a 3 amp load. Nothing died or got any warmer than they normally would.

I heard reports from LOR users that claimed that they had display item failures though no one has been able to prove that it was because of the controller and not a failure that would have occurred anyway. I am using the identical TRIAC’s that are in all of the LOR controllers and have had zero problems. I talked to Dan Baldwin (owner of Light-O-Rama) who said that he unofficially has tried similar experiments with a LOR controller and has had no problems either.

The only actual problems that you would see are that the channel won’t turn off because it gets re-triggered by the kickback voltage of the coil.