Signal phase angle measuring device - uses repetitive waveform shaped for phase comparison with input signal

摘要

The device is for diverse studies such as internal combustion engine timing to the control of the sweep of oscilloscopes. A sawtooth signal derived from the repetitive reference signal is applied to the input of an operational amplifier circuit which acts as an inverter with unity gain. The second input of the amplifier is connected to a reference voltage such as zero volts. A switch connects the amplifier stage input or output to an input of a comparator to reverse the sign of the phase angle. A potentiometer provides a signal whose phase angle is required. The comparator output is connected to two transistors which conduct depending on the phase difference and the output is read on a galvanometer.