| 摘要 |
Apparatus and methods for AC power regulation primarily intended for inductive loads (e.g., fluorescent lights, motors, etc.) which provides substantial reduction in power consumption while also providing a leading power factor, reduced harmonic distortion, reduced crest factor and reduced noise. The system is self-adjusting for a wide range of loads and can reduce power consumption by 25% in lighting loads while producing minimal reduction in light output. The system utilizes a triac and parallel capacitor bank in series with the load. The triac is turned-on in response to a near-zero differential voltage measured across the Triac and is turned-off near the peak of each AC half cycle by shunting current around the Triac. The capacitor absorbs the inductive turn-off voltage spike caused by the collapsing magnetic field in the ballast at the instant of triac turn-off. This energy in turn provides longer on period for the lamp, thereby permitting more light and increased operating efficiency. The turn-off time is adjusted to regulate power at a reduced level responsive to line voltage load current and load power sense signals.
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