Hitachi, Ltd.

Hitachi Metals, Ltd.

Kohei Yabuno

Kenichi Onda

Norikazu Tokunaga

Shin Nakajima

Kojin Abe

Noboru Ogawa

Kozin Abe

Takeshi Uemura

A magnetically controlled switching regulator which controls an output voltage using a saturable reactor, wherein the saturable reactor is constituted by a first winding through which an output current flows and a second winding through which a reset current flows. The energy for resetting the saturable reactor is supplied from a capacitor in a smoothing circuit for an output voltage. A turn ratio between the first and second windings is set so that a sufficiently high reset voltage is obtained. Since the reset current of the saturable reactor does not flow through a transformer, the saturation of the transformer and a high increase in temperature thereof do not occur, so that the core of the transformer can be miniaturized and a high gain of the output voltage control circuit can be derived.

Switch mode power supply having magnetically controlled output

In accordance with the present invention, there is provided a power supply apparatus comprising a primary winding of a main transformer and a semiconductor device with a control electrode connected in series between both electrodes of a DC power source, a drive current being fed to said control electrode of said semiconductor device via an auxiliary transformer, and output being obtained on a secondary winding of said main transformer by turning on and off of said semiconductor device, wherein a tertiary winding is provided on said main transformer and a negative polarity drive current is flowed into said semiconductor device via said tertiary winding when said semiconductor device is to turn off.

Switching power supply apparatus

A high-voltage power supply device comprising a first DC power source, a first reactor supplied with direct current from this first DC power source, a resistor connected in parallel with the first reactor, a current interrupter initially permitting circulation of the flow of current between it and the first reactor and subsequently interrupting the flow of the circulating current therethrough, at least one auxiliary reactor connected in parallel with the first reactor, a second DC power source supplying direct current to the auxiliary reactor, an auxiliary current interrupter initially permitting circulation of the flow of current between it and the auxiliary reactor and subsequently interrupting the flow of the circulating current therethrough, and a diode and switch means connected between the first reactor and the auxiliary reactor. This switch means is turned off when the direct current is supplied to the first reactor from the first DC power source and turned on when the current is supplied to the first reactor from the auxiliary reactor. The high voltage appearing across the resistor in response to the interruption of the flow of the current circulating through the first reactor and the current interrupter is taken up by the diode and is not applied to the auxiliary reactor and the auxiliary current interrupter, so that the auxiliary reactor and the auxiliary current interrupter can be prevented from being destroyed by the high voltage.

High-voltage power supply device

Growing community of inventors

Hitachi, Japan

Kohei Yabuno