light dimmer

This simple triac dimmer can be used to control incandescent filament lamps up to 1500 W. The circuit operates on the phase-control principle. The main con- trol is provided by P2. This determines the rate at which C2 charges and hence the point along the mains waveform at which the voltage on C2 reaches the breakdown voltage of the diac, which is when the triac is triggered. P 1, in con- junction with Rl and Cl determines the minimum brightness level, or alterna- tively may be used as a fine brightness control. Interference suppression is provided by R2 and C3.