APPROACH SENSOR FOR DISPLACEMENT DETECTION

• Main Author: ASADA TADAYOSHI
• Format: Patent
• Language: English
• Published: 01.04.1982
• Subjects: BASIC ELECTRONIC CIRCUITRY; DETECTING MASSES OR OBJECTS; ELECTRICITY; GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; PHYSICS; PULSE TECHNIQUE; TESTING

PURPOSE:To obtain a voltage, proportional to a distance, at a wide range, by a method wherein a feedback amount to a resonance circuit is minutely controlled. CONSTITUTION:A means, which can minutely control a feedback amount to a resonance circuit, is provided. For example, one end of an LC oscillating circuit 20 is connected to a base of a transistor 11, and the other end to an emitter via a variable resistance 5 to perform a positive feedback from a collector via a resistance 10. The output of the transistor 11 is inputted to another transistor 16 via a smoothing circuit 21. This causes changing of an inductance if an object to be detected approaches a detecting coil 1, and the change is produced into the damping of an oscillating output. The adjustment of the variable resistance 5 permits the rapid or the gradual stoppage of an oscillation to obtain a sensor having a high resolution.