Analyzer circuit an inductive position sensor

US5425073A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Rainer Bitzer · Rutesheim, DE
• Bernd Dittmer · Ludwigsburg, DE
• Franz Schwarz · Feldbach, AT
• Karl Haegele · Schorndorf, DE
• Thomas Wieja · Eningen unter Achalm, DE
• Helmut Schneider · Hersbruck, DE

Key dates

• Filing date: Sep 10, 1993
• Grant date: Jun 13, 1995
• Expiry date: Sep 10, 2013

Classification

• Technology area (CPC G): Physics
• CPC primary: G01D5/248
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The analyzer circuit includes a first oscillator producing an output signal having a first frequency depending on an inductance of an inductive position sensor having two oscillator coils positioned near a movable part; a switching device in the first oscillator for alternatingly connecting one of the two coils and simultaneously disconnecting the other according to a state of the switching device; a frequency divider for converting the output signal at the first frequency to another output signal at another frequency; a counter for counting a pulse signal under control of the other output signal of the frequency divider; a second oscillator connected to the counter and providing input pulses at a fixed frequency to the counter, which counts the input pulses under control of the other output signal of the frequency divider; a start synchronizing circuit for starting and synchronizing the divider and the counter; a flip-flop connected to the frequency divider and to the switching device to switch the state of the switching device; and an arithmetic-logic unit connected to the counter to receive a count from it and having a device for generating a digital output signal characteristic…