Honda Motor Co., Ltd.

Sanken Electric Co., Ltd.

Keihin Corporation

Yoshikazu Nomoto

Toshiaki Ariyoshi

Takafumi Tsurumi

Akio Iwabuchi

Mitsuteru Yano

Masaki Kanazawa

Yuji Minoda

Kazuya Aizawa

Takayuki Ohta

Masanori Kawamoto

Norimasa Yamada

An apparatus measures a voltage of a cell while scanning a group of cells in a cell stack, in which a plurality of cells is electrically connected in series. The apparatus has a first switching device and a voltage detecting device. The first switching device is connected in series with a signal line carrying a voltage of a cell. The voltage detecting device detects the voltage of the cell, which is electrically connected with signal lines carrying voltages of cells belonging to a group. When the first switching device is electrically connected with a connecting point between two successive groups of cells, the first switching device is shared by the two groups.

Apparatus for measuring voltage

A voltage measurement device includes a first group of switches Q, Q, a second group of switches Q, Qand a third groups of switches Q, Q. By turning on the third group of switches Q, Q, the first group of switches Q, Qare turned on, so that a condenser Cis charged by voltage impressed between a voltage input terminal A and a voltage input terminal B. While the first group of switches Q, Qare turned off by tuning off the third group of switches Q, Q, the second group of switches Q, Qare turned on, so that voltage retained in the condenser Cis generated between a voltage output terminal G and a voltage output terminal H.

Voltage measurement device

A control section sets a positive side switching element of a positive side detection section and a negative side switching element of a negative side detection section to ON, thus outputting an ON signal. When the switching elements are set ON, a predetermined current outputted from a positive side constant current source and a negative side constant current source, or a portion of this current, flows through detection resistors. A ground fault decision section decides whether a ground fault has occurred in the positive or the negative side of a direct current power source, based upon the value of an output voltage detected by a positive side voltage detector, or upon the value of an output voltage detected by a negative side voltage detector. Ground faults are accurately detected with a simple structure.

Ground fault detection device

Growing community of inventors

Saitama, Japan

Yoshikazu Nomoto