Two-state Hall element proximity sensor device with lamp indicator

• US 4,296,410 A
• Filed: 02/25/1980
• Issued: 10/20/1981
• Est. Priority Date: 02/25/1980
• Status: Expired due to Term

• Current Assignee: Allegro Microsystems Incorporated (Sanken Electric Company Limited)
• Original Assignee: Sprague Electric Company
• Inventors: Higgs, Jacob K., Avery, Grant D.
• Primary Examiner(s): Caldwell, Sr., John W.
• Assistant Examiner(s): Nowicki, Joseph E.
• Application Number:
  US06/124,389
• Time in Patent Office: 603 Days
• Field of Search: 340/686, 324/251, 323/89 H, 323/94 H, 323/368, 307/309, 338/32 H, 361/376
• US Class Current: 340/679
• CPC Class Codes: H03K 17/18 Modifications for indicating state of switch
• CPC Class Codes: H03K 17/9517 using galvanomagnetic devices

Abstract

An integrated circuit including a Hall element and a threshold detector is encased in a plastic housing with the plane of the Hall element parallel with a face of the housing, providing a two-state Hall element proximity sensor. A light emitting diode (L.E.D.) is mounted in the housing and is connected to the output of the detector, providing visual indication of the state of the sensor. A kit includes the sensor and a compatible magnet to provide to users of little skill, proximity sensor parts that are easily assembled and made immediately effective in use.

Claims

1. A proximity sensor kit having two basic component parts capable of being mounted to a fixed and a movable member of a machine, respectively, for producing an electrical output signal and a visual indication when a portion of said movable member moves to within a predetermined distance with respect to a portion of said fixed member, said kit comprising the combination of said parts, namely:

(a) a two-state Hall element proximity sensor device, adapted to be mounted to said fixed member portion, comprising a Hall element and a voltage-threshold detector means being connected to the output of said Hall element for generating a particular electrical signal only when the magnetic field at said element exceeds a predetermined magnitude in a predetermined polarity;

a housing containing said sensor device, the plane of said element being positioned parallel to and adjacent to an outer face of said housing; and

an indicator lamp means for providing one state of illumination only when excited by said signal, said lamp means including a lamp that is connected to the output of said detector means and is attached to and protrudes from another face of said housing to be seen from many directions of viewing and to provide visual indication whether said particular electrical signal is present;

(b) a magnet adapted to be mounted to said movable member portion in such a position that when said fixed portion is within said predetermined distance, one of the poles of said magnet substantially faces said sensor, said magnet providing an ambient magnetic field at said Hall element of said predetermined polarity and of said predetermined magnitude.

2. The proximity sensor kit of claim 1 wherein said sensor device additionally includes an electrical termination means at said housing for connecting an electrical energy source to said Hall element and to said detector means and for connecting said output of said detector means to a remote voltage or current responsive device.

3. The proximity sensor kit of claim 2 wherein said termination means is comprised of three lead wires extending from a surface of said housing.

4. The proximity sensor kit of claim 1 wherein said sensor device additionally includes a mounting flange extending in a first plane from said housing, the plane of said Hall element being in a second plane that is at right angles to said first plane.

5. The proximity sensor kit of claim 1 wherein said sensor device is a silicon integrated circuit.

6. The proximity sensor kit of claim 1 wherein said lamp is a discrete light emitting diode having a transluscent dome portion.