Voltage measuring circuit - uses difference between two voltages as reference voltage for integrator capacitor discharge

摘要

The circuit has an integrator which is used for charging a capacitor during a specified time interval. It is used for counting the time of the capacitor discharged to a reference voltage. In order to measure a resistor (Rx) connected to input terminals (MP1, MP2) and used for the capacitor (C1) discharge, the difference (Uref-Ux') between the reference voltage (Uref) and voltage drop (Ux') across the resistor (Rx), a part of a voltage divider connected across the reference voltage (Uref), is used instead of the reference voltage.