发明名称 |
Electronic ballast with interface circuitry for phase angle dimming control |
摘要 |
A gas discharge lamp dimming ballast has a two wire input for connection to the hot dimmed and neutral leads of a phase control dimmer. The ballast has an improved topology in which a pre-conditioner supplies a substantially constant DC voltage to a ballast stage including an inverter, a resonant tank output and a control circuit. A dimming interface circuit derives a dimming signal having a voltage equal to the average value of the rectified output voltage of a full-bridge rectifier feeding the pre-conditioner circuit. The dim signal is independent of the DC rail voltage and, in combination with the maintenance of a substantially constant DC rail voltage, permits of improved dimming control while providing the ease of installation of a two wire ballast. The response time of the interface circuit relative to the pre-conditioner is selected to avoid power imbalances. The ballast also includes an EMI filter and circuitry to prevent capacitive hold-up by the EMI filter of the rectified voltage to preserve the conduction angle for the interface circuit.
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申请公布号 |
US5559395(A) |
申请公布日期 |
1996.09.24 |
申请号 |
US19950414859 |
申请日期 |
1995.03.31 |
申请人 |
PHILIPS ELECTRONICS NORTH AMERICA CORPORATION |
发明人 |
VENKITASUBRAHMANIAN, SREERAMAN;FARKAS, THOMAS;JAYARAMAN, RAJ;XIA, YONGPING;BRUNING GERT;VELDMAN PAUL |
分类号 |
H05B37/02;H05B41/285;H05B41/36;H05B41/392;(IPC1-7):H05B37/02 |
主分类号 |
H05B37/02 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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