发明名称 |
ELECTRONIC BALLAST WITH CONTROLLED LAMP PREHEATING |
摘要 |
An electronic ballast provides controlled preheating for a discharge lamp. A power converting circuit receives a DC power input and converts it into an AC power output. A starting circuit coupled to the power converting circuit generates a high voltage for starting the lamp. A control circuit controls the power converting circuit to generate AC power output to the lamp dependent on a mode of operation. A symmetry detecting circuit determines a positive-negative symmetrical state of the output power provided to the discharge lamp with respect to ground. The control circuit has a starting mode wherein the discharge lamp is triggered to start with a high voltage generated by the starting circuit, an electrode heating mode wherein the AC power output of the power converting circuit is controlled to a first frequency for heating each lamp electrode, and a steady-state mode wherein the AC power output of the power converting circuit is controlled to a second frequency for maintaining lighting of the discharge lamp. The control circuit shifts from the electrode heating mode to the steady-state mode when the symmetry detecting circuit determines that the AC power output is in a positive-negative symmetrical state in the electrode heating operation.
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申请公布号 |
US2010109542(A1) |
申请公布日期 |
2010.05.06 |
申请号 |
US20090605450 |
申请日期 |
2009.10.26 |
申请人 |
KOMATSU NAOKI;YAMAHARA DAISUKE |
发明人 |
KOMATSU NAOKI;YAMAHARA DAISUKE |
分类号 |
H05B41/36 |
主分类号 |
H05B41/36 |
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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