Diagnostic device of battery on vehicle

Abstract

Abstract PURPOSE:To check the voltage of a battery, which is not affected by charging and discharging, before the rotation of an engine and check a charging device also, by providing a holding circuit, which is disconnected with turning-on of a taking-in key switch of the battery voltage, and a means which checks whether the battery voltage is higher than a prescribed value or not. CONSTITUTION:A capacitor 16 (the holding circuit) is charged through a switch 12 by a battery 10 while the engine is stopped; and when a key switch 18 is turned to a position ACC, the capacitor 16 is connected to a buffer 30 because a switch 12 is opened and a switch 12A is closed, and consequently, this buffer 30 outputs a battery voltage VB just before turning of the key switch to the position ACC. This battery voltage VB is inputted to comparators 24 and 26, and these comparators output signals S2 and S3 in case of VB>VR2 and VB> VR3. A comparator 22 receives the battery voltage through a position IG of the key switch 18 and generates a signal S4 when this voltage, namely, a battery voltage VB' during driving of a car is lower than VR1. A microcomputer 20 uses these signals to diagnose the battery.

Inventors

• 👤 Yasuhiro Fujita
• 👤 泰裕 藤田
• 👤 Takashi Sakamoto
• 👤 隆 坂本
• 👤 Keiji Sakamoto
• 👤 坂本　啓二
• 👤 Seiji Ishikawa
• 👤 誠司 石川

Bibliographic Details