| 摘要 |
PROBLEM TO BE SOLVED: To provide a light-dimming circuit for a discharge lamp capable of breaking in a low efficiency state. SOLUTION: The light-dimming circuit 10 capable of breaking in a low-efficiency state includes a resonant unit 11, a rectifier 21, a half-bridge output unit 31, a first current control switch Q1, a second current control switch Q2, a first trigger unit DD1, a second trigger unit DD2, a selecting unit 41, a starting unit 42, and retaining/off unit 46. The starting unit 42 is connected to the rectifier 21 and the first trigger unit DD1 and makes the discharge lamp operate to emit light when voltage gradually increases. The retaining/off unit is connected to the rectifier 21 and the second trigger unit DD2 and passes electricity to the second current control switch Q2 to continuously operate after the discharge lamp is started, the second trigger unit DD2 is triggered when the voltage falls to a predetermined value, and the discharge lamp is turned off by turning off the second current control switch Q2. COPYRIGHT: (C)2010,JPO&INPIT |
