Hi , I have designed and made a triac switch , to turn ON and OFF a 3-speed AC motor that works with 220VAC. with tree triac series an all the triacs have a snubber (R-C) circuit.
the problem is when the circuit is in OFF state , the triac outputs shows that it has 220V voltage(with a Phase Meter screwdriver) . but when i check with a multimeter it doesnt show any voltage. i know that it doesnt have a real voltage but i dont know what is the problem?
The snubber (and the triac, to a lesser degree, due to leakage) pass a certain amount of current due to the resistor and capacitor reactance. With the load connected, you should measure very little voltage, but with the load disconnected you might measure close to line voltage. The current will be V/sqrt((Xc^2+R^2)), so if you have a 0.1uF in series with 100R, the current @ 220VAC 60Hz will be around 8mA into a low impedance load.
Best regards, Spehro Pefhany
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