Abstract: A power supply apparatus is disclosed including a device for producing an oscillatory signal, and an output circuit for producing from said oscillatory signal an alternating-current output voltage, characterized by the provision of a regulating unit connected in series with the output circuit for producing a controllable voltage drop. The regulating unit includes a control device operable in response to a signal derived from the output circuit for controlling the voltage drop in response to a change in an output parameter of the output circuit.

Abstract: An alternating-current voltage regulator including a pair of input terminals adapted for connection with an alternating current supply voltage, a pair of output terminals adapted for connection with a load, a series-connected first switching device, a parallel-connected second switching device, an inductor connected in series with the first switching device, and a control device connected between the regulator output terminals and the switching devices for switching the switching devices at a second frequency which is high with respect to the frequency of the supply voltage. Consequently, a quantity of energy stored in the inductance during one part of a cycle of the second frequency is transferred to the output as an increase in voltage of the output with respect to the input during another part of the cycle.