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. 20, 2001
Filed:
Oct. 30, 1998
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An electric leak detecting apparatus used for an electric motorcar includes a source for generating an AC signal, which supplies a sine wave detecting signal S,of a single frequency fl Hz to between a vehicle body and a low potential side or a high potential side of a battery pack, a condenser having capacitance Cd for insulating the AC source from the low potential side or high potential side of the battery pack with respect to direct currents and for connecting the AC source to the low or high potential side of the battery pack with respect to alternating currents. Also included are a voltage detecting circuit for detecting an AC signal voltage of the detecting signal S,at either side of the condenser, a current detecting circuit for detecting an AC signal current of the detecting signal S,, an admittance detecting circuit for computing an electric leak admittance |Y| from the AC signal voltage and AC signal current of the detecting signal S,a phase discriminating circuit for finding a phase difference between the AC signal voltage and AC signal current of the detecting signal S,, a resistance component detector for detecting a resistance component by computing a real part of the admittance |Y| from the admittance and phase difference. Also included is a comparison device for comparing the resistance component to a threshold value.