Hi,

Thanks for the answer. Does the SSR needs extra circuitry such as RC filters as I have seen in some of the MOC322/triac stages?

You are talking about pulses getting shorter and shorter as the temperature reaches the set point, right? Is is a periodic signal? If yes, then what would be the period of your signal? Also what would be the lenght of the shortest pulse?

For my project I figured out a period of 1 or 2 seconds, the sortest pulse would be 20ms (1s period) or 40ms (2s period), corresponding to 5% of the period. That's where my % came from. Trigerring the heat source during 20ms over 1s correponds to 5% power applied.

Denis.