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US4803425A Expired / Lapsed US ⏱️ 0.0 years remaining

Multi-phase printed circuit board tachometer

Assignee: Xerox Corp
•
Filing: 1987-10-05
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Granted: 1989-02-07
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Expires: 2007-10-05
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Abstract

Abstract This invention relates to a multi-phase printed circuit board (PCB) tachometer for accurate measurement of the rotational speed and direction of an electric motor. The multi-phase output not only provides rotation velocity in the form of the conventional a-c output signal, but also provides rotation direction information, in addition to providing a higher rotational resolution than conventional PCB tachometers. According to a first embodiment of the present invention, a multi "winding", multi-phase PCB tachometer that uses a single multi-pole magnet is constructed by using double sided boards with plated through holes. In a second embodiment, a multi-phase tachometer configuration is disclosed in which the number of radial printed circuit traces and the number of pole magnets are not equal, whereby the individual voltages generated across each radial segment will not be in phase, and thus can provide rotational direction information as well as velocity information.

Inventors

  • 👤 Melvin E. Swanberg

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 14:40
CPC Classifications
H; H02; H02K; H02K21/00; H02K21/12; H02K21/24; G; G01; G01P; G01P13/00; G01P13/02; G01P13/04; G01P13/045; G01P3/00; G01P3/42; G01P3/44; G01P3/48; G01P3/481; G01P3/487; H02K3/00; H02K3/04; H02K3/26

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 217 words
A printed circuit winding pair for use in AC tachometers comprising: a first winding on a board substrate, said winding having a first terminal and a second terminal, a continuous conductive trace from said first terminal to said second terminal, said trace following a generally serpentine pattern, said pattern being circular in shape, such that said serpentine pattern comprises radial loops extending outwardly from a central point, a second winding on said board substrate, said second winding having a first terminal and a second terminal, a continuous conductive trace from said first terminal to said second terminal, said trace following a generally serpentine pattern, said pattern being circular in shape, such that said serpentine patterns comprises radial loops extending outwardly from a central point, said second winding being rotated slightly from and interwined with said first winding, wherein the outer circular parts of said first winding is formed on the reverse side of said board substrate and connected to the radial traces of said first winding by plated through holes, and wherein the inner circular parts of said secured winding is formed on the reverse side of said board substrate and connected to the radial traces of said second winding by plated through holes, such that said first and second windings are electrically isolated from each other.
Claim 2
Dependent Claim 217 words
A printed circuit winding pair for use in AC tachometers comprising: a first winding on a board substrate, said winding having a first terminal and a second terminal, a continuous conductive trace from said first terminal to said second terminal, said trace following a generally serpentine pattern, said pattern being circular in shape, such that said serpentine pattern comprises radial loops extending outwardly from a central point, a second winding on said board substrate, said second winding having a first terminal and a second terminal, a continuous conductive trace from said first terminal to said second terminal, said trace following a generally serpentine pattern, said pattern being circular in shape, such that said serpentine patterns comprises radial loops extending outwardly from a central point, said second winding being rotated slightly from and interwined with said first winding, wherein the outer circular parts of said first winding is formed on the reverse side of said board substrate and connected to the radial traces of said first winding by plated through holes, and wherein the inner circular parts of said secured winding is formed on the reverse side of said board substrate and connected to the radial traces of said second winding by plated through holes, such that said first and second windings are electrically isolated from each other.

References Cited (Backward Citations)

US2915721A Cited
US3765082A Cited
US4551676A Cited
US4494100A Cited
US4488076A Cited
US4697144A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-02-07 1992-08-08 1993-02-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-02-07 1996-08-08 1997-02-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-02-07 2000-08-08 2001-02-07 $7700.00 Window Closed / Lapsed

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