Patent ID: 7969098
Filing Date: 2011-06-28
Classification: H05B

Abstract:
1. A dimming circuit for a discharging lamp, comprising: a resonant unit including a first capacitance and a second capacitance in series, and a first inductance in parallel with said first capacitance and second capacitance; a rectification unit connected to said resonant unit to transfer an AC power to a DC power; a half-bridge output unit, which is connected to a discharging lamp, including a first electric-controlled switch and a second electric-controlled switch in series, wherein said first electric-controlled switch and said second electric-controlled switch are in series with said rectification unit, and have a control terminal respectively; a first switch device and a second switch device connected to said control terminals of said first electric-controlled switch and said second electric-controlled switch respectively; and a selection unit including a start sub-unit and a maintain/turn-off sub-unit, wherein said start sub-unit is connected to said rectification unit and said first switch device to turn on said first switch device and said second electric-controlled switch when a potential is rising that turns on said discharging lamp, and said maintain/turn-off sub-unit is connected to said rectification unit and said second switch device to turn off said second switch device and keep turning on said second switch device when said discharging lamp is lighting, and said maintain/turn-off sub-unit further turns on said second switch device to turn off said second electric-controlled switch for turning off said discharging lamp when said potential is lower than a predetermined value.