| 摘要 |
PURPOSE:To protect an element against stress upon contact of an output line and a power supply line. CONSTITUTION:Power is fed from a DC power supply 1 through a lighting circuit A comprising an inverter circuit to a discharge lamp 2 thus lighting the discharge lamp with high frequency power. The discharge lamp 2 is connected through choke coils L21, L22 with the output of the lighting circuit A. Current flowing through the discharge lamp 2 is then detected, at the opposite ends thereof, through current transformers CT1, CT2, respectively. When the difference between thus detected currents exceeds a predetermined level, a comparing circuit 6 stops operation of the lighting circuit A. |
