twin dimmer

Dimmer circuits are always popular and this one offers two independent controls in one. Control of each section of the circuit is provided by a type S576 which is an improved version of the S566. This type of IC controls the phase gating by short or long command pulses emanating from a touch pad. Pulses shorter than 60 ms are treated as noise. Short pulses between 60 ms and 400 ms cause the lamp to be switched on or off, depending on whether it was off or on respectively. If the touch pad is touched for more than 400 ms, the appropriate lamp is dimmed at a certain speed. If the finger is held on the touch pad, the lamp will go out completely and will then slowly light up again: when it reaches full brightness (and the finger is still on the pad), it will begin to dim again, and so on. The S576 is available in three versions: A, B, and C. With the A and C ver- sions, the lamp is always switched on or off half-way between maximum and minimum brightness, and it first attains maximum ...