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:
Jul. 19, 2005
Filed:
Dec. 02, 2002
Hirofumi Yudahira, Hamana-gun, JP;
Hirofumi Yudahira, Hamana-gun, JP;
Panasonic EV Energy Co., Ltd., Shizuoka, JP;
Abstract
A leakage detection apparatus is provided, capable of performing high-speed leakage detection during startup of a motor-vehicle such as an HEV. The apparatus includes a signal generatorfor generating a signal whose frequency is set variably, a resistorfor attenuating the signal in cooperation with an insulation resistor between a high-voltage circuitand a low-voltage circuit, a coupling capacitorfor capacitance-coupling one end of a resistant element to the high-voltage circuit, an LPFwhose cut-off frequency is set variably, for attenuating a high frequency component via the capacitive element to be superimposed on the signal via the resistant element, a leakage detection portionfor comparing an amplitude level of the signal via the LPF with a predetermined threshold value so as to detect the presence or absence of leakage between the high-voltage circuit and the low-voltage circuit, and a control portionfor setting the signal frequency of the signal generator and the cut-off frequency of the LPF after startup of the low voltage circuit and before startup of the high-voltage circuit to be higher than those after startup of the high-voltage circuit.