| 摘要 |
A voltage converter and a method for converting AC to DC. A MOSFET (42, 118) conveys current from a full wave rectifier to charge a capacitor (60) that supplies current to a load (64). In a first embodiment, two transistors (32, 34) are connected as a differential pair to control the voltage applied to the gate of the MOSFET, referenced to a zener voltage developed across zener diode (36) that is connected to the emitters of the two transistors. In a second embodiment, a single transistor controls the voltage applied to the gate of the MOSFET, relative to a zener voltage of a zener diode (132). The MOSFET charges the capacitor while the voltage applied to its gate from the rectified signal is greater than the voltage across the capacitor. |
