Circuit arrangement for comparing the synchronism or tracking between two analog signals

US4286306A · kind A · utility

Assignee

• Messerschmitt-Boelkow-Blohm Gesellschaft mit beschraenkter Haftung · DE

Inventors

• Hermann Kraus · Ottobrunn, DE
• Peter Kirchlechner · Rottenburg a. d. Laaber, DE
• Robert Rieger
• Wolf-Dieter Schuck · Putzbrunn, DE

Key dates

• Filing date: Jul 31, 1979
• Grant date: Aug 25, 1981
• Expiry date: Jul 31, 1999

Classification

• Technology area (CPC G): Physics
• CPC primary: G01R19/16585
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The synchronism or tracking between two analog signals is compared by a cuit arrangement having two inputs to which these analog signals are applied. A comparator circuit compares the two signals and provides a trigger or energizing signal to a switch which in turn produces an error signal when the two compared signals deviate from each other to an extent larger than a predetermined limit. One input is connected to the comparator circuit through a heterodyning circuit wherein the respective analog signal is heterodyned by a heterodyning signal which varies in its polarity. The comparator circuit includes a polarity detector which provides a signal signifying a positive or a negative difference between the amplitudes of the two polarity signals. A discriminator circuit is operatively connected to the comparator to provide a switch energizing signal when the difference signal does not have any zero transitions or passages with the frequency of the heterodyning signal.