The positive half-cycle for an ac input signal is applied to a wave rectifier (20, 22), a filter (41) and a voltage regulator (30, 31) for generating a dc output signal. The ac input signal is also applied to a transistor (50) in either the common emitter or common source configuration which shifts the ac input signal by 180 degrees. This signal is then applied to another rectifier (21, 23) for converting the shifted ac input signal into a pulsating dc output signal. Then shifted dc output signal is applied to a second capacitor filter to reduce the signal variations. The final stage for the second output stage is also a voltage regulator (32, 33) (i.e., two series zener diodes). The transformerless power supply produces either a dual positive or dual negative dc voltage supply. In addition, the voltage supply circuits may include a relay voltage, which may be controlled by a control circuit.
CROSS-REFERENCE TO RELATED PATENT APPLICATION
This patent application is a 371 of International Application No. PCT/US00/04152 filed Feb. 18, 2000, which claims priority to the originally filed Provisional Application No. 60/120,586 filed Feb. 18, 1999, the teachings and disclosure of which are hereby incorporated in their entireties by reference thereto. This PCT application was published in English.
In this power converter, a first capacitor for stepping down of voltage, a first diode for half-wave rectification, and a second capacitor for smoothing are interposed between first and second input connections for input of AC voltage; and a second diode for discharge of the first capacitor is interposed between the second input connection and an input end of the first diode. AC voltage supplied from an AC power supply is divided (stepped down) by the first and second capacitors, rectified to DC voltage by the first diode, smoothed by the second capacitor, and supplied, as an output voltage defined by Zener diodes, to the load side through the first and second output connections.
