发明名称 |
Method and device for driving a gas discharge lamp |
摘要 |
A method for operating a fluorescent lamp (5) having a nominal power (WLa) and stabilized with an EM ballast (B) comprises the steps of during normal operation, short-circuiting the lamp during a closing time interval (CTI) during each current period in order to operate the lamp at a reduced power. The method comprises the step of detecting whether the lamp is stabilized by means of an inductive ballast or by means of a capacitive ballast. If it is found that the ballast is capacitive, the timing of the closing time interval (CTI) is set such that the closing time interval (CTI) has a first closing time segment (CTS1) immediately before a zero-crossing of the current, having a first duration (Δ1) higher than zero, and a second closing time segment (CTS2) immediately after said zero-crossing of the current, having a second duration (Δ2) higher than zero. |
申请公布号 |
US8896237(B2) |
申请公布日期 |
2014.11.25 |
申请号 |
US201113635032 |
申请日期 |
2011.03.01 |
申请人 |
Koninklijke Philips N.V. |
发明人 |
Vankan Peter Johannes Wilhelmus;Chow Wai Pang;Van Haastrecht Johannes Theodorus Jacobus |
分类号 |
H05B37/02;H05B41/392;H05B41/295;H05B41/04 |
主分类号 |
H05B37/02 |
代理机构 |
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代理人 |
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主权项 |
1. Method for operating a fluorescent lamp having a nominal power (WLa) and stabilized with an EM ballast (B) and supplied with a supply power comprising a supply voltage and supply current with current frequency (f) and current period (T), the method comprising the steps of, after starting and during normal operation, short-circuiting the lamp during an uninterrupted closing time interval (CTI) during each current period in order to operate the lamp at a reduced power, the method further comprising the steps of:
detecting whether the lamp is stabilized by means of an inductive ballast in an L-system or stabilized by means of a capacitive ballast in an LC-system; if it is found that the lamp is stabilized by means of an inductive ballast in an L-system, setting the timing of the closing time interval (CTI) such that the closing time interval (CTI) is located entirely between two successive zero-crossings of the current; or if it is found that the lamp is stabilized by means of a capacitive ballast in an LC-system, setting the timing of the closing time interval (CTI) such that the closing time interval (CTI) has a first closing time segment (CTS1) immediately before a zero-crossing of the current, having a first duration (Δ1) higher than zero, and a second closing time segment (CTS2) immediately after said zero-crossing of the current, having a second duration (Δ2) higher than zero. |
地址 |
Eindhoven NL |