PURPOSE: To easily measure the phase difference with a specific accuracy by a method wherein a alternating current voltage is changed to a square wave of a constant voltage, and then, the phase difference is taken out separately between the delayed one and the advanced one through logical operations.
CONSTITUTION: Alternating current voltages from alternating current sources 1, 2 are amplified by a non-inverting amplifier 3 and an inverting amplifier 4, changed to square waves and output to an AND circuit 5, respectively. Meanwhile, an output from the non-inverting amplifier 3 is fed to a time delay circuit comprised of a resistance 7 and a capacitor 8 through an inverting amplifier 6 and finally supplied to an inverting amplifier 9. Outputs from the amplifier 9 and circuit 5 are supplied to an AND circuit 10. An output of the AND circuit 10 is, through a resistance 11, a capacitor 12 and a resistance 13, impressed to an operational amplifier 14. An output of the amplifier 14 is fed to an advanced phase output terminal 25. An output of the amplifier 9 is supplied to an operational amplifier 22 through an amplifier 17, an AND circuit 18 etc. An output of the operational amplifier 22 is fed to a phase output terminal 26. Accordingly, the phase difference within ±50 degrees can be easily measured within the accuracy of ±1 degree.
YOSHITAKE HIDEKI
HORI FUJIO
