Abstract: A circuit incorporating a circuit element for recovering the energy stored in the parasitic input capacitance of a power transistor at turn-on. The circuit includes a resonating element, such as a transformer, and a diode coupled between a voltage source and a power transistor, such as a field effect transistor. A switching device is switchably coupled between the input of the power transistor and the voltage source, and between the input of the power transistor and the resonating element. The resonating element is adapted to recover and store the energy stored in the parasitic capacitance of the power transistor when it is turned on, thus improving the efficiency of the circuit. The diode is adapted to avoid loading of the power source. The energy is recovered and stored until a new turn-on interval is required or until there is a need for other power requirements. This improves the operating efficiency of a system using the circuit.

Abstract: A linear regulator employing a field effect transistor (FET) pass element to supply a pulsed load is programmed by a cooperating switching regulator such that an increased voltage differential is maintained across the FET to reduce response time during the leading edge of the load pulse and to thereafter reduce the voltage differential to achieve reduced power consumption and increased efficiency during the remainder of the load pulse.

Abstract: A base drive regulator for regulating the base drive voltage of the output transistor of a switching amplifier. The inputs of a comparator are separately connected to a reference voltage of either an independent source or the base of the output transistor and to a resistor network connected between the collector and emitter of the transistor. The output from the comparator is utilized to indirectly control the conductivity of the output transistor to maintain the output transistor just at saturation.