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:
Nov. 04, 2003
Filed:
Nov. 13, 2002
Norikazu Tokunaga, Hitachi, JP;
Kenichi Onda, Hitachi, JP;
Takeshi Onaka, Hitachi, JP;
Satoru Masuyama, Odawara, JP;
Ryouhei Saga, Takasaki, JP;
Katsunori Hayashi, Odawara, JP;
Other;
Abstract
A DC power supply device comprises an AC/DC converter , a DC/DC converter , and a DC converter 3 converting DC power from a battery to DC voltage for connecting to output terminals of the AC/DC converter. The DC power supply device is provided with a controlling circuit which observes a charging control level and a load sharing level, impresses a charging command on a UPS controlling part controlling the DC converter, and simultaneously provides a PFC controlling part controlling the AC/DC converter with a current command when a voltage level is less than the charging control level, stops only the charging command when the voltage level is more than the charging level and less than the load sharing level, and provides the UPS controlling part and the PFC controlling part with current commands when the voltage level is more than the load sharing level. The AC/DC converter and the DC converter supply power in parallel when a load is more than a prescribed value, and the DC converter supplies power as a backup when a trouble is present in an AC power input.