well, i am talking about acustic noise.
i used the triac (BT136-4Amps, 600V) for switching like 25W @12V. it was making some acoustic noise. i guess low frequency.
i also used it for controlling some lamps powered from the mains(150W, 250W). it makes a bigger noise.
now, you know those potentiometers for light, that you put them in place of the normal switch? those make noise too. and use triacs as well.
and the noise gets annoying....i stay somewhere close to the switch. and if it is quet in the room, i don't like the noise.
so.....why do they make this noise and can it be stopped?