| 摘要 |
<p>A load control device adapted to be coupled between an AC power source and an electrical load for controlling the power delivered to the load includes a power supply having an energy storage capacitor (C out) and a charge pump circuit (222) adapted to conduct an input charging current through the load and to conduct an output charging current through the energy storage capacitor to thus generate a DC supply voltage (Vcc) across the energy storage capacitor, where the output charging current has a magnitude greater than the input charging current. The charge pump circuit includes a switched capacitor (C10-C60) operable to charge through the load during a first half -cycle, and to discharge into the energy storage capacitor in a second, subsequent half -cycle. The charge pump circuit operates at line frequency and the magnitude of the input charging current is substantially small so as to avoid generating noise in a noise - sensitive circuit of the load control device.</p> |
