The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 10, 1997
Filed:
Oct. 17, 1995
Katsunori Hayashi, Odawara, JP;
Akihiko Kanouda, Hitachinaka, JP;
Tadashi Takahashi, Hitachi, JP;
Hideaki Horie, Hitachi, JP;
Kenichi Onda, Hitachi, JP;
Yasuo Abe, Chigasaki, JP;
Masayoshi Sato, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A parallelized power supply system including a plurality of switching power supplies each having a circuit for limiting rush current generated when a main switch is turned on. This system can be installed in an apparatus which requires the functions such as power uninterrupted operation and live wire insertion/dismount. Each switching power supply has another power supply for driving the rush current limiter circuit and a relay circuit for supplying relay driving current and making a connection of relay contacts after a predetermined time lapse after the operation start of the switching power supply. An a.c. power is supplied via the relay contacts to each switching power supply. The relay driving time set in the rush current limiter circuit is different for each switching power supply. Accordingly, concentration and excess of rush current when the relay is driven can be suppressed, and sparks at contact pins of a connector to be otherwise generated when the switching power supply is mounted on the connector, can be eliminated so that radiation noises and connector breakage can be avoided. Each of the switching power supplies connected in parallel has a current detecting resistor connected between the low voltage side of a load and the low voltage side of a voltage regulator d.c. output, and at least one operational amplifier for detecting a change in the d.c. output, the negative power supply terminal of the operational amplifier being connected to the current detecting resistor at its one end on the load side.