| 摘要 |
The circuit includes first and second circuit lines. A rectifier with output connected across the lines and input connectable to an AC source provides a rectified DC input voltage on the lines. An inductor is connected in one of the lines and an output capacitor is connected across the lines receives a DC output voltage. A control switch includes two power terminals and a control terminal. The power terminals are connected across the power lines between the inductor and the output capacitor. A current representative signal is provided by a unit responding to the current flow through the inductor. An oscillator with frequency higher than the AC source closes the control switch in each cycle. A unit provides an input voltage representative signal. A summation circuit sums the input voltage signal and a reference voltage giving a summation signal used by an error unit providing an error feedback signal. A comparison unit uses the error signal and the current representative signal to open the control switch when the current signal reaches a set value relative to the error signal. |
