Honda Giken Kogyo Kabushiki Kaisha

Kouji Sakai

Kazunori Sato

Shugo Kondo

Takafumi Tsurumi

Tomohiko Maeda

Naoki Ohsawa

Hideyuki Jinzai

An apparatus for measuring battery voltage is provided that can detect battery voltage with high accuracy, and also can be miniaturized with cost and noise reduced. The apparatus comprises: a capacitor which is charged to the voltage of each module, switches which connect and disconnect this capacitor and the module, a voltage follower which outputs the voltage across the capacitor, and switches which connect and disconnect the voltage follower and the capacitor. For the aforementioned switches, photo MOSFETs are used. Furthermore, to prevent discharge from the capacitor, a voltage follower is installed. Therefore, by using not a complicated circuit but inexpensive and simple elements, a low cost and miniaturized apparatus for measuring battery voltage is realized.

Battery voltage measurement apparatus

A power supply control device for an electric vehicle capable of reducing the power consumption in a battery monitor assembly adapted for monitoring a residual electric charge in a main battery 4. In response to an operation which causes increasing or decreasing the residual charge in the main battery 4, a start-up unit 200 produces a start-up demand pulse P3. Upon receiving the start-up demand pulse P3, a power supply controller circuit 60 closes a switch 59 to allow the power from a sub battery 5 to be supplied the battery monitor assembly 100. When the battery monitor assembly 100 is activated, its power supply maintaining means 102 delivers a self-hold signal S4 to maintain the switch 59 being closed. The battery monitor assembly 100 keeps monitoring the residual charge in the main battery 4 while it is energized by the sub battery 5.

Power supply control device for electric vehicle

Growing community of inventors

Wako, Japan

Kouji Sakai