首页>
外国专利>
Electronic ballast having a triac dimming filter with preconditioner offset control
Electronic ballast having a triac dimming filter with preconditioner offset control
展开▼
机译:电子镇流器,具有三端双向可控硅开关元件调光滤波器,带前置调节器偏移控制
展开▼
页面导航
摘要
著录项
相似文献
摘要
A dimming ballast for use with a phase control dimmer, and particularly a triac dimmer, includes an EMI filter selected with a high impedance to avoid excessive voltage and peak currents in the filter due to resonance with the phase controlled AC waveform at low conduction angles, when the load presented by the lamp is low. The EMI filter includes a filter capacitor connected at the output of a rectifier. The ballast also includes circuitry to sense the rectified DC voltage and to discharge the filter capacitor when the rectified voltage is at or near zero, to thereby keep the EMI filter loaded and prevent misfiring of the triac dimmer. In a favorable embodiment, the sensing and discharge function is carried out by a pre-conditioner of the switched-mode type.
展开▼