Electric circuit for operating gas-discharge lamp at alternating current power source, has ring exhibiting half of high impedance earth connections from virtual point to earth potential over detection circuit when lamp is provided in ring

摘要

The circuit has a transformer (1) provided with primary and secondary windings (4, 5). A gas-discharge lamp (6) and the secondary winding are connected in series and form a closed ring. The ring is formed from a regular sequence in accordance with a sample lamp-secondary winding-lamp-secondary winding or lamp-lamp- secondary winding-lamp-lamp-secondary winding. The ring exhibits half of high impedance earth connections from a virtual potential null point i.e. center tap (7), to a earth potential (9) over a detection circuit (8) for current asymmetry when the lamp is provided in the ring. The detection circuit is designed as a resistive voltage divider.