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:
Mar. 07, 2006
Filed:
Dec. 23, 2004
Nobuo Mayumi, Toyohashi, JP;
Nobuo Mayumi, Toyohashi, JP;
Denso Corporation, Kariya, JP;
Abstract
In a voltage booster circuit, a switching transistor turns on and off a flow of an electric current in a booster coil thereby to boost a voltage supplied form a d.c. power source. A back-up circuit is connected to the booster coil to store the boosted voltage as an output voltage. A current detection circuit detects an electric current flowing in the switching transistor and turns off the switching transistor, when the detected current reaches a predetermined level. An off-period control circuit variably controls an off-period of the switching transistor after the switching transistor is turned off. The off-period control circuit varies the off-period in accordance with a voltage difference between the output voltage and an upper limit threshold voltage. The off-period of the switching transistor is increased as the output voltage increases toward the upper limit threshold voltage