Voltage digitizing method for speed control of fan, involves calculating value of capacitor voltage differing from one of two limits of voltage range, based on time intervals

摘要

The capacitor (80) is charged to a voltage (Um) through impedance converter (66) and resistor (76). The voltage at the capacitor is modified to a first limit of voltage range at time interval (T1). The voltage at the capacitor is modified from the second limit to the first limit at time interval (T2). The value of the capacitor voltage differing from one of the two limits is calculated based on time intervals (T1,T2). An Independent claim is also included for arrangement for digitizing voltage.