Abstract: A switching power source comprising a pair of output terminals, a first switch element, a reactor and a filter which are connected to each other in series between one of the terminals of an input DC power source and one of the output terminals; a second switch element connected between a connecting node for the reactor and the filter and the other terminal of the input DC power source; and means for causing energy stored in the reactor to be fed back for regeneration to the input DC power source when the switch elements are turned off, wheein the switching power source is characterized by that the first and second switch elements are alternatively actuated for ON-OFF actions at a prescribed time ratio.

Abstract: An AC voltage regulator includes an output voltage sensing and regulating device having a suitable filter characteristic to attenuate AC components therein occurring in the frequency ranges corresponding to the almost periodic oscillations or abnormal oscillations, or high frequency components of distorted waves which appear in the AC output voltage and are causes for such abnormal oscillations. The AC voltage regulator does not need to use a dummy load to suppress almost periodic oscillations even when the load is extremely small. The output voltage of the AC voltage regulator is free from abnormal oscillation components such as almost periodic oscillations and low frequency oscillations.

Abstract: A constant voltage regulator involving a feedback loop by which frequency dependence may be eliminated and at the same time, hunting phenomenon in case of low load can be suppressed without inserting a dummy resistance or a reactor in its circuit, whereby high reliability may be compatible with low cost.The constant voltage regulator comprises a linear reactor and a resonance capacitor connected in series to an input power source, and a variable reactor connected in parallel with said resonance capacitor and involves a feedback loop, a saturable reactor being used as said variable reactor, and current flowing through said saturable reactor being subjected to feedback control in response to load or output voltage.

Abstract: A power conversion device of simple configuration for a solar cell which permits the solar cell to be connected to the commercial power source and enables the maximum electric power corresponding to the amount of incident sunlight to be drawn from the solar cell.A power conversion device for a solar cell of this invention comprises a voltage controlled oscillator capable of generating oscillation with a frequency which is the function of the dc output voltage of said solar cell, an inverter controlled based on the output frequency of said voltage controlled oscillator to receive the dc output current of said solar cell and convert said dc output current into an alternating current, and an inductor serving to connect the ac output from said inverter to a commercial power source.

Abstract: An uninterruptible ac power supply permits parallel operation between a commercial ac line and an inverter unit, greatly simplifies the monitoring of the commercial ac line and minimizes the transient of output voltage during the switching of mode. The uninterruptible ac power supply is comprised of an iron core divided with magnetic shunts into three sections and has an output winding, a winding for a commercial ac line and a winding for an inverter unit, one each wound on the aforementioned three sections of the iron core, the said three windings so disposed that the output winding is wound on one terminal section and the windings for the commercial ac line and the inverter unit are wound on the remaining two sections.