Abstract
A simple and inexpensive circuit for measuring the phase angle difference between two waves with lead/lag indication is described. The proposed circuit may be adopted in the laboratory as an attachment to a commercially available analogue/ digital multimeter to measure the phase difference. The response is linear over a range 0 to + 180
°
and is unaffected by the input frequencies in the range 6 Hz-1.2 kHz. For distorted waveforms, the paper also gives a simple scheme to measure the displacement angle which in turn suggests its use in a high-power-factor self-compensated alternating voltage controller.