| 摘要 |
PROBLEM TO BE SOLVED: To provide electric discharge lamp lighting equipment, which enables life-end stage detection and protection of the electric discharge lamp, moreover with high safety and at a low cost having a simple configuration. SOLUTION: The detection circuit consists of a series circuit of a capacitor C9 for direct-current component detection and a resistance R6, that is connected between a connecting point of a capacitor C0 for direct-current cut and a choke coil L1 for resonance, and the circuit ground. If the electric discharge lamp load La carries out a half-wave discharge, a positive or negative voltage occurs to the capacitor C9 for direct current component detection according to the discharging direction. A voltage comparison circuit 2 distinguishes voltage generated and outputs the detection output to a control circuit 3. The control circuit 3 controls switching elements Q1 and Q2 of an inverter circuit, based on the detection output, and reduces or steps the output of the inverter circuit. |
