Position sensor

• US 4,339,953 A
• Filed: 08/29/1980
• Issued: 07/20/1982
• Est. Priority Date: 08/29/1980
• Status: Expired due to Term

• Current Assignee: Aisin Seiki Co., Ltd. (Aisin Corp.)
• Original Assignee: Aisin Seiki Co., Ltd. (Aisin Corp.)
• Inventors: Iwasaki, Shinichiro
• Primary Examiner(s): Gill, James J.
• Application Number:
  US06/182,842
• Time in Patent Office: 690 Days
• Field of Search: 73/517 R, 73/517 B, 73/654, 324/207, 324/208, 336/30, 336/110
• US Class Current: 73/654
• CPC Class Codes: G01B 7/003 for measuring position, not involving coordinate determination coordinate measuring G01B7/004
• CPC Class Codes: G01D 5/12 using electric or magnetic means G01D5/06 takes precedence
• CPC Class Codes: G01D 5/20 by varying inductance, e.g. by a movable armature

Abstract

A position sensor comprising a ferromagnetic member operatively connected to an operation means and movable in response to displacement of the operation means, a magnetically soft member surrounded by an electrical coil secured adjacent to a range of movement of the ferromagnetic member, and a displacement pulse phase conversion unit including a permanent magnet. Voltage pulses are applied to one end of the electrical coil, the other end of which is connected in series with a resistor. A voltage drop across the resistor is detected and a time lag of the resistor voltage, which time lag corresponds to displacement of the operation means, is provided in the form of an analog voltage or a digital code.

Claims

1. A position sensor for detecting operational displacement of an operation means, comprising:

a ferromagnetic member movable in response to displacement of said operation means;

permanent magnet means for providing a magnetic field;

core means including a magnetically soft material disposed adjacent said ferromagnetic member and said permanent magnet means for forming a magnetic circuit therewith;

at least one electrical coil disposed on said core means;

detector means for detecting a change of intensity of magnetic flux produced in said core means by the magnetic field of said permanent magnet means in response to a displacement of said strong ferromagnetic member, comprising

means for applying a pulse voltage to said at least one coil; and

means for measuring the time delay occurring from the application of said pulse voltage until saturation of said core means.

2. A position sensor according to claim 1, further comprising;

non-magnetic connection means for connecting said ferromagnetic member to said operation means.

3. A position sensor according to claim 1, in which said core means of magnetically soft material consists of:

an amorphous magnetic member.

4. A position sensor according to claim 1, in which said ferromagnetic member consists of:

an amorphous magnetic member.

5. A position sensor according to claim 1, further comprising:

said core means of magnetically soft material comprising a pair of magnetically soft members disposed adjacent said permanent magnet means at opposite sides thereof.

6. A position sensor according to claim 1, further comprising:

said permanent magnet means comprising a pair of permanent magnets; and

a pair of magnetically soft members disposed in opposing relationship with the respective permanent magnets.