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Snubbers act like a pressure relief valve around the switch and slow the resulting dI/dT for inductive loads which reduces the peak voltage. The problem is you an incandescent light is not inductive load so your snubber won't really slow anything at all. Despite having a snubber filter, I can see on my scope that the ac output still has a hard cutoff in the ...


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R13 and C6 are not really suitable for mains operation. C6 should be X2 rated. The capacitor for C6 you're currently using is piezo electric, so it is most likely causing the buzz you hear. R13 isn't surge rated. If you want to slow the edge, you need an inductor in series with the load like all good phase control light dimmers have. R6/C13 is only for ...


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Check voltage supply to PIR sensor. The capacitor C1 is only feeding half cycle, so no much current will flow through it. Another diode D4 is necessary to charge this capacitor in opposite polarity, or you can move the zener D2 in this place. Limiting resistor R2 should better placed in series with capacitor C1, so it will work in both polarities. I have ...


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This Question, @Spehro’s answer and the comments catched my attention to search some more. I found a very interesting Application Note from ST Electronics, covering exactly the triggering of Triac by MCU. It explains the triggering features and even show how to calculate some circuits presented, and their limitations. Here are some examples, driven at ...


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