Control appts. for high voltage gas discharge lamps - has high frequency circuit with transformer secondary having resonance circuit allowing variable frequency

摘要

The control appts. for a high voltage gas discharge lamp (19) has input provided by a pair of transistors (13, 14) coupled to the primary side of a transformer (15) and with switching controlled by a control module (10). The transformer provides 500 to 500 V conversion with a capacitor (16) in the primary to inhibit the d.c. magnetisation. On the secondary side is a resonance circuit consisting of an inductance (17) and a capacitor (18). The process is improved by a current converter (20) in the secondary circuit to provide feedback via an amplifier (21) to control the input stage. ADVANTAGE - Allows simple means of dimming.