Fluorescent lamp starter with constant-current dimmer switch - ensures electrode heating by current regulated independently of ratio of discharge current to total lamp current

摘要

The lamp (LL) is connected to an invertor (WR) by a series resonant combination of a capacitor (12) and an inductor (13). Different phases of operation are instigated by a bridging and dimming switch (14) which periodically short-circuits the lamp electrodes (E1,E2) together. The pulse sequence generated by the switching circuit (IC2) in response to brightness detection (17) after a 400 ms preheating interval is synchronised (16) with half-cycles of the invertor control circuit (IC1) opening and closing electronic switches (10,11) for DC direct connections (+,-). ADVANTAGE - Sufficient heating of electrodes is ensured in any dimming condition by simple circuit.