CURRENT SENSOR AND BATTERY REMAINING POWER SENSING SYSTEM

摘要

A battery remaining power sensing system for stably sensing the battery remaining power accurately comprises a current sensing circuit (30) installed in a device body (1a) and a remaining power calculation microcomputer (34) installed in a battery pack (2a). The current sensing circuit includes a reference voltage generating section (31) for generating a reference voltage (Vb) and an A/D converter (26) for converting the reference voltage (Vb) and the terminal voltage (Vi) of the current sensing resistive element (24) to two pieces (D(Vi), D(Vb)) of digital data. The remaining power calculation microcomputer calculates the discharge current (I) flowing through a power supply line (28) by using the ratio between the two pieces of digital data.