VOLTAGE MEASURING CIRCUIT AND VOLTAGE MEASURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a voltage measuring circuit and a voltage measuring method capable of measuring voltage without using an DC/DC converter as a supply source of a reference voltage to an A/D converter. SOLUTION: The voltage (electric potential at D point) which the A/D converter 3 gained through a diode 7 is converted to a digital value 8 using a supply voltage A (electric potential at A point) from a battery 1 as the reference voltage and based on the digital value 8, the microcomputer 2 calculates the supply voltage A from the battery 1.