Abstract: A voltage regulating or control system employing a triac for controlling the power supplied to a load from an alternating current (a.c.) voltage source uses an oscillator as a phase controller to initiate a first switching pulse in each half-cycle of the voltage source. A feedback loop responsive to the first pulse in each half-cycle acts to increase the output frequency of the oscillator to thereby provide pulse train firing of the triac. An additional circuit acts to define a "window" which serves to establish a period within each half-cycle of the a.c. source during which the delivery of switching of pulses is prohibited.

Abstract: This disclosure is of an inverter type power supply including an actively switched damping circuit for limiting voltage transients in the inverter circuitry. Such damping is accomplished by switching an energy absorbing element into parallel circuit relationship with the inverter transformer during periods in which transients normally occur, the energy absorbed during these transients then being either dissipated or stored and later returned to the inverter transformer for improved circuit efficiency.

Abstract: A regulated power supply which may be of the A.C.-to-D.C. type utilizes a ries arrangement of inverters because of a voltage rating of these inverters with respect to the magnitude of the D.C. driving voltage available either as a consequence of rectifying an A.C. voltage source or other reasons. The regulator has a self-balancing feature which insures that all of the inverters equally share the D.C. driving voltage and also includes a protection feature which safeguards the inverters against damage caused by a malfunction of any one of the units.