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:
Apr. 25, 2000
Filed:
Jun. 01, 1999
Shinichi Ishii, Saitama, JP;
Hiroshi Miki, Hyogo, JP;
Fuji Electric Co., Ltd., , JP;
Abstract
An ac/dc converting circuit adapted to output a direct voltage that is higher than a full wave rectified voltage of an alternating input voltage is provided which includes an alternating current filter, and a condenser with a positive electrode and a negative electrode coupled to a dc output side of a full wave rectifying circuit. The full wave rectifying circuit includes a switching portion having upper and lower arms each having a semiconductor rectifying element and a self-commutated semiconductor switching element, and a rectifying portion having upper and lower arms each having a semiconductor rectifying element. The semiconductor rectifying elements in the upper arms of the full wave rectifying circuit has a common cathode coupled to the positive electrode, and the semiconductor rectifying elements in the lower arms has a common anode coupled to the negative electrode. The ac/dc converting circuit further includes a resistor provided between a coupling point of the rectifying elements of the upper arms of the full wave rectifying circuit and the negative electrode. In operation, a signal for controlling an ON/OFF state of the switching element of the lower arm of the switching portion is generated while the switching element of its upper arm is in an OFF state, when the direct output voltage is higher than the input alternating voltage, and a voltage at an ac input terminal between the rectifying elements of the switching portion is lower than a voltage at an ac input terminal between the rectifying elements of the rectifying portion.