A four terminal full wave rectifier circuit that can be used as a pin for pin replacement for the full wave diode rectifier circuit commonly used in DC power supply circuits. Two full wave rectifier circuits that can efficiently supply the DC currents required in both discrete and integrated circuits being operated at low DC supply voltages are disclosed. Both circuits utilize two n-channel, enhancement mode Junction Field Effect Transistors (JFET) and two p-channel, enhancement mode Junction Fi...

A four terminal full wave rectifier circuit that can be used as a pin for pin replacement for the full wave diode rectifier circuit commonly used in DC power supply circuits. Two full wave rectifier circuits that can efficiently supply the DC currents required in both discrete and integrated circuits being operated at low DC supply voltages are disclosed. Both circuits utilize two n-channel, enhancement mode Junction Field Effect Transistors (JFET) and two p-channel, enhancement mode Junction Fi...

A full wave rectifier includes an operational amplifier having an inverting terminal connected to the emitter of a transistor. A first resistor is connected between a first power source and the collector of the transistor. A second resistor is connected between a second power source and the emitter of the transistor. When the first and second resistors have an identical value and first and second power sources have same absolute voltage but opposite polarity, the voltage on the transistor collec...

A synchronous rectification circuit for power converters operable under fixed and/or variable frequencies where no current sense circuit or phase-lock circuit are needed is provided. It has a power switch coupled to a transformer for the rectification. A signal-generation circuit is used for generating a control signal in response to a magnetized voltage of the transformer, a demagnetized voltage of the transformer, and a magnetization period of the transformer. The control signal is coupled to ...

A synchronous rectification circuit for power converters operable under fixed and/or variable frequencies where no current sense circuit or phase-lock circuit are needed is provided. It has a power switch coupled to a transformer for the rectification. A signal-generation circuit is used for generating a control signal in response to a magnetized voltage of the transformer, a demagnetized voltage of the transformer, and a magnetization period of the transformer. The control signal is coupled to ...

A vector controller for a polyphase synchronous rectifier, a method of vector-controlling a polyphase synchronous rectifier, and a synchronous rectifier incorporating the vector controller or the method. In one embodiment, the vector controller includes: (1) an input line voltage detector configured to detect voltages on at least two rectifier input lines and produce therefrom a neutral excursion vector and (2) a neutral excursion compensator, coupled to said input line voltage detector, that ap...

A switch mode AC/DC converter with input current shaped for unity power factor. Input current is modulated by input voltage, and input inductor and isolation transformer are driven with the same duty ratio, with a low voltage across bulk capacitor. This voltage is determined only by input voltage amplitude. Energy stored in the leakage inductance of the transformer is returned back to the internal DC source. A soft switching circuit is connected to the primary side, eliminating the need for high...

A rectifier has two half-controlled bridge rectifiers which are connected in parallel to provide DC power to DC bus lines. Each bridge rectifier receives AC power through inductances such as series inductors or an isolation transformer with a single primary and two secondaries. Each bridge rectifier has a full bridge of diodes, with active switching devices connected in parallel with half of the diodes in the bridge. The switching devices can be controlled to provide unity power factor at the AC...

A synchronous rectifier control circuit for controlling a synchronous rectifier of a power converter is disclosed. According to one embodiment, the control circuit includes a differentiator circuit responsive to the output voltage of the power converter. The control circuit also includes a summing circuit responsive to an output of the differentiator circuit and a step function signal. The control circuit further includes an integrator circuit responsive to an output of the summing circuit. In a...

Synchronous rectifier circuits are provided for each secondary windings of a transformer. Field-effect transistors of which ON voltage is lower than the forward voltage of a diode are provided in each of the synchronous rectifier circuits. In an energy saving mode, the field-effect transistors in the synchronous rectifier circuit that outputs a diving voltage are turned OFF. A comparator circuit outputs a signal corresponding to a difference between a control voltage output from one of the synch...