| 摘要 |
PROBLEM TO BE SOLVED: To suppress the damage of contacts of a switch and a relay and to protect an electronic ballast from an excessive surge due to the chattering of the contacts by connecting a spark killer connected with a capacitor and a resistor in series at the level for slightly oscillating the oscillation open section of the electronic ballast between the contacts of the switch feeding electric power to many discharge lamp luminaires. SOLUTION: A power supply 1 is applied to electronic ballasts stored in discharge lamp luminaire groups 41, 42, 43 through a CR spark killer 3 when a switch a is turned off. A charging current flows in the DC smoothing capacitor of each electronic ballast, and the oscillation section of the electronic ballast slightly oscillates. When the switch 2 is closed, the DC smoothing capacitor is already charged to some degree, a rush current flowing into the switch 2 is suppressed, and the damage of contacts is reduced by the effect of the CR spark killer 3. A large surge is prevented from being applied to a semiconductor. |
