摘要 |
<p>A touch control switch suitable for connection between a lamp load and a supply circuit in a lighting installation for alternating current and comprising a semiconductor switching element with a gate electrode, a counting circuit with a forward stepping input and a digital control output connected to the gate electrode of the semiconductor switching element via a trigger pulse generating circuit for controlling the conduction of the semiconductor switching element in dependence on the condition of activation of the digital control output, and a control pulse shaping circuit having an output connected to the forward stepping input of the counting circuit and a first and second input terminal for connection to a first and second, respectively terminal of the supply circuit via a touch sensitive impedance. The trigger pulse generating circuit comprises an edge-triggered mono-pulse generating circuit that has a first input for leading edge triggering and a second input for trailing edge triggering jointly connected to the supply circuit.</p> |