dimmer RFI

[hrc]

From some of the tech notes I've seen, typically the RFI filter on the dimmed side of the triac is just a 100uH choke, nothing else too special other than to ensure it isnt saturated.

Also there appears to be a snubber of some type often used as well, but if I use a 'snubberless' triac, such as a STmicro BTA08, would i still need the .47uF and 2K resistor? Is that part of the RFI circuit? I don't believe it is, just acts as a snubber on the output.

 

[hrc]

And...forgot to add....looking for the smallest possible choke, surface mount preferred, saturation of 8A

 

[sreid]

ST has an app note at their website on their snubberless Triacs (you have to dig to find it). They don't claim you can eliminate the snubber and it's probably a bad idea in the real world especially if the load is remote from the Triac. They also show spike catchers.