Timed dimmer circuit suitable for stairway lighting - has starter capacitor charged through transistor lying across rectifying bridge

摘要

The control circuit consists of a trigger, e.g. a dial, a starter capacitor preparing the ignition current of the electronic a.c. switch, a setting unit for the loading current of the starter capacitor and containing at least one controllable capacitor whose storage level can be independent of the charge state, and a charging circuit loading the controllable capacitor in dependence upon a switch. The setting unit determining the loading current of the starter capacitor (C1) uses a transistor (T3) whose switching path lies in the crossing branch of a rectifying bridge (D8-11). The charging current for the starter capacitor flows along this switching path. The control electrode of the transistor (T3) is connected to the capacitor (C4).