Pulse generation by changing magnetic field

• US 4,309,628 A
• Filed: 02/22/1980
• Issued: 01/05/1982
• Est. Priority Date: 02/22/1980
• Status: Expired due to Term

• Current Assignee: The Echlin Manufacturing Company
• Original Assignee: The Echlin Manufacturing Company
• Inventors: Wiegand, John R.
• Primary Examiner(s): Moffitt, James W.
• Application Number:
  US06/123,703
• Time in Patent Office: 683 Days
• Field of Search: 307/419, 365/133, 310/154, 310/155, 310/156, 310/152
• US Class Current: 307/419
• CPC Class Codes: F02P 7/0672 using Wiegand effect
• CPC Class Codes: G01P 3/4815 using a pulse wire sensor, e.g. Wiegand wire
• CPC Class Codes: G01P 3/488 delivered by variable reluctance detectors
• CPC Class Codes: H03K 17/97 using a magnetic movable element
• CPC Class Codes: H03K 3/45 by the use, as active elements, of non-linear magnetic or dielectric devices

Abstract

A pulser unit is composed of two high strength magnets spaced apart from one another and establishing an intense magnetic field therebetween. Forward faces of the two magnets establish a working surface for the pulser unit. A Wiegand wire module consisting of a Wiegand wire segment around which a pickup coil is wound is mounted in the pulser unit immediately behind the working surface of the pulser unit and adjacent the sides of the two spaced apart magnets. The magnetic field is sufficiently strong to determine the state of the Wiegand wire. When a low reluctance element is brought adjacent to the front of the working surface, the field is substantially distorted and the field to which the Wiegand wire is subjected changes materially. The result is that the Wiegand wire switches state and the substantial rate of change of the flux in that switching of state is sensed by the pickup coil to provide an output pulse. Similarly, removal of the low reluctance element causes the field to revert so that the wire switches state back thereby inducing an output pulse in the pickup coil. The pulser can conveniently be kept stationary while the actuating low reluctance element is moved past the working face of the pulser.

Claims

1. A pulser for use in the generation of a pulse in response to magnetic field distortion comprising:

first and second magnets spaced apart from one another and oriented relative to one another so that a first pole of said first magnet and a second pole of said second magnet define a working surface of said pulser, the polarity of said magnets having opposite orientation so that said first pole of said first magnet and said second pole of said second magnet have opposite polarities,

said magnets establishing a magnetic field between them,

a Wiegand wire module having a predetermined position in the field between said magnets, said module including a Wiegand wire segment and a pickup coil,

said first and second magnets and said module all being positioned rearward of said working surface of the pulser,

the configuration of said magnetic field between said magnets distorting materially in response to a material change in the reluctance path provided adjacent to and forward of said working surface of the pulser,

said position of said Wiegand wire in said field being such that said wire switches state in response to said material distortion of said field.

2. The pulser of claim 1 wherein said module is positioned along a plane adjacent a side of said magnets.

3. The pulser of claims 1 or 2 wherein said module is positioned along a plane adjacent said working surface.

4. The pulser of claims 1 or 2 wherein said magnets are high energy magnets. PG,13

5. The pulser of claim 3 wherein said magnets are samarium cobalt.

6. The pulser of claim 4 wherein said magnets are samarium cobalt.

7. A pulse generator comprising:

a pulser having a working surface, and a low reluctance element,

said pulser and said element being movable relative to each other such that said element traverses across said working surface of said pulser, adjacent to and in front of said working surface,

said pulser including first and second spaced apart magnets determining a magnetic field therebetween and a Wiegand wire module positioned in said magnetic field between said first and second magnets, said magnets and module all being positioned rearward of said working surface,

said Wiegand wire module including a Wiegand wire segment and a pickup coil wrapped around said segment,

said first and second magnets having essentially parallel magnetic axes and opposite polarities, a first pole of said first magnet having a first polarity and a second pole of said second magnet having a second polarity, said first pole of said first magnet and said second pole of said second magnet substantially defining said working surface of said pulser,

the permeability of said low reluctance element being sufficient to materially distort said magnetic field between said magnets in the vicinity of said wire, when said element is adjacent said working surface,

said wire switching state in response to said material distortion of said field.

8. The pulser of claim 7 wherein said module is positioned along a plane adjacent a side of said magnets.

9. The pulser of claims 7 or 8 wherein said module is positioned along a plane adjacent said working surface.

10. The pulser of claims 7 or 8 wherein said magnets are high energy magnets.

11. The pulser of claim 9 wherein said magnets are samarium cobalt.

12. The pulser of claim 10 wherein said magnets are samarium cobalt.

13. The method of generating a pulse in response to the switching of state of a Wiegand wire wherein the wire is provided in a module having a pickup coil wrapped around a segment of Wiegand wire comprising the steps of:

establishing a relatively intense magnetic field between first and second magnets spaced from one another and polarized in opposite directions from one another,

deploying the Wiegand wire module in said field between said magnets and along a plane adjacent a side of said magnets, and

bringing a low reluctance element adjacent to a plane defined by a south pole of said first magnet and a north pole of said second magnet to materially distort the configuration of the field in the vicinity of said module.