Browse Prior Art Database

Phase Angle Measurement

IP.com Disclosure Number: IPCOM000076969D
Original Publication Date: 1972-May-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 26K

Publishing Venue

IBM

Related People

Chambers, DW: AUTHOR

Abstract

An input sine wave and a reference sine wave of the same frequency are compared to produce a DC output dependent upon the phase angle between the two signals. No ripple is produced.

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Phase Angle Measurement

An input sine wave and a reference sine wave of the same frequency are compared to produce a DC output dependent upon the phase angle between the two signals. No ripple is produced.

As shown in the figure, the circuit includes two 90 degrees phase shifters and two multipliers. The input sine wave is applied to phase shifter 1 and multiplier 4. The reference sine wave of the same frequency is applied to phase shifter 2 and multiplier 3. The outputs of the multipliers are applied to differential amplifier 5.

The output from differential amplifier 5 is a DC signal of magnitude proportional to the sine of the phase angle between the input sine wave and the reference sine wave. As no ripple is produced at the output, no filtering is required.

The circuit may be used to measure fast-phase changes over the range of 0 to 360 degrees phase change.

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