Hitachi, Ltd.

Hitachi Media Electronics Co., Ltd.

Hitachi Mizusawa Electronics Co.

Kazuhiro Takizawa

Hiroshi Kimura

Akihiko Kanouda

Masami Joraku

Tetsunosuke Nakamura

Tetsuya Obara

Makoto Kawamura

Yoshio Miyamoto

A circuit construction comprising a diode and a capacitor is connected to a secondary coil of a thin transformer such as a wire-type transformer. An excitation energy is discharged during a reset time of the transformer, and this excitation energy is accumulated in the capacitor, thereby output voltage is obtained through the capacitor. A direct current output voltages having two outputs is obtained through one transformer. A small volume and a light weight of the transformer, so that a compact and thin power supply apparatus can be obtained. Since a winding ratio of the transformer can be made small, a copper loss of the transformer can be reduced. It is unnecessary to select a higher switching frequency and a manufacturing cost of the power supply apparatus can be reduced.

Power supply apparatus having separate plural outputs

A compact, thin-type, noise-tolerant and highly reliable electric power unit includes an input portion through which a predetermined voltage is applied, a plurality of power circuits for generating a plurality of different voltages from the predetermined voltage applied to said input portion, an output portion for outputting the plurality of different voltages generated in the plurality of power circuits, a control unit having a function to stabilize the plurality of different output voltages, and an insulated substrate which supports the input portion, the plurality of power circuits, the output portion and the control unit, and further has a printed wiring pattern for electrically coupling the constituent components of the electric power unit. By disposing each group of components which compose each of plurality of power circuits into a predetermined area corresponding to each output voltage, or by arranging the components such that the height of each of the plurality of constituent components for the power circuits is adapted to become approximately the same as or less than the height of the transformer, a compact and thin-type elective power unit which is noise-tolerant and highly reliable is achieved.

Electric power unit

Growing community of inventors

Yokohama, Japan

Kazuhiro Takizawa