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US4491794A Expired / Lapsed US ⏱️ 0.0 years remaining

Hall effect device test circuit

Assignee: AG Communication Systems Corp
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Filing: 1982-10-29
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Granted: 1985-01-01
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Expires: 2002-10-29
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Abstract

Abstract A Hall effect device test circuit which detects Hall effect device operate and release point failures. A magnetic field circuit, an analog-to-digital conversion circuit, a storage circuit, a comparison circuit and a visual indicator circuit are included. The magnetic field circuit causes the Hall effect device under test to switch between its operate and release states. The analog-to-digital conversion circuit provides a digital value, representative of the intensity of the magnetic field existing at the time of switching. These digital values are then stored in the storage circuit. The comparison circuit compares the stored switching values to predetermined thresholds and causes an appropriate visual pass/fail visual signal to be provided.

Inventors

  • 👤 William J. Daley
  • 👤 Hendrik W. Van Husen

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 18:20
CPC Classifications
G; G01; G01R; G01R35/00; G01R33/00; G01R33/02; G01R33/06; G01R33/07

Claims Analysis

Total Claims: 16
Claim 1
Independent Claim 426 words
A Hall effect device test circuit for use in a test system including a source of a power signal, said test circuit comprising: magnetic field means connected to said source and operative in response to said power signal to periodically provide a magnetic field of varying intensity; voltage reference means connected to said source and operative in response to said power signal to periodically provide a sample voltage of varying magnitude and proportional to the intensity of said magnetic field; a Hall effect device connected in magnetic field proximity to said magnetic field means and operative in response to each occurrence of said magnetic field of a first predetermined intensity to provide an electrical signal of a first characteristic, and operative in response to each occurrence of said magnetic field of a second predetermined intensity to provide an electrical signal of a second characteristic; conversion means connected to said Hall effect device and said voltage reference means, and operative in response to each electrical signal of said first characteristic and said sample voltage to provide a first digital representation of said sample voltage; said conversion means further operative in response to each electrical signal of said second characteristic and said sample voltage to provide a second digital representation of said sample voltage; first threshold means operative to provide a first predetermined digital signal; second threshold means operative to provide a second predetermined digital signal; third threshold means operative to provide a third predetermined digital signal; fourth threshold means operative to provide a fourth predetermined digital signal; comparison means connected to said conversion means and operative in response to said electrical signal of said first characteristic being less than or equal to said first predetermined digital signal to provide a first operate-pass signal and further operative in response to said electrical signal of said first characteristic being greater than or equal to said second predetermined digital signal to provide a second operate-pass signal; and further operative in response to said electrical signal of said second characteristic being less than or equal to said third predetermined digital signal to provide a first release-pass signal, and further operative in response to said electrical signal of said second characteristic being greater than or equal to said fourth predetermined digital signal to provide a second release-pass signal; and first indicating means connected to said comparison means and operative in response to said first and second operate-pass signal to provide a sensible operate-pass signal, and further operative in response to said first and second release-pass signals to provide a sensible release-pass signal.
Claim 2
Dependent Claim 426 words
A Hall effect device test circuit for use in a test system including a source of a power signal, said test circuit comprising: magnetic field means connected to said source and operative in response to said power signal to periodically provide a magnetic field of varying intensity; voltage reference means connected to said source and operative in response to said power signal to periodically provide a sample voltage of varying magnitude and proportional to the intensity of said magnetic field; a Hall effect device connected in magnetic field proximity to said magnetic field means and operative in response to each occurrence of said magnetic field of a first predetermined intensity to provide an electrical signal of a first characteristic, and operative in response to each occurrence of said magnetic field of a second predetermined intensity to provide an electrical signal of a second characteristic; conversion means connected to said Hall effect device and said voltage reference means, and operative in response to each electrical signal of said first characteristic and said sample voltage to provide a first digital representation of said sample voltage; said conversion means further operative in response to each electrical signal of said second characteristic and said sample voltage to provide a second digital representation of said sample voltage; first threshold means operative to provide a first predetermined digital signal; second threshold means operative to provide a second predetermined digital signal; third threshold means operative to provide a third predetermined digital signal; fourth threshold means operative to provide a fourth predetermined digital signal; comparison means connected to said conversion means and operative in response to said electrical signal of said first characteristic being less than or equal to said first predetermined digital signal to provide a first operate-pass signal and further operative in response to said electrical signal of said first characteristic being greater than or equal to said second predetermined digital signal to provide a second operate-pass signal; and further operative in response to said electrical signal of said second characteristic being less than or equal to said third predetermined digital signal to provide a first release-pass signal, and further operative in response to said electrical signal of said second characteristic being greater than or equal to said fourth predetermined digital signal to provide a second release-pass signal; and first indicating means connected to said comparison means and operative in response to said first and second operate-pass signal to provide a sensible operate-pass signal, and further operative in response to said first and second release-pass signals to provide a sensible release-pass signal.
Claim 3
Dependent Claim 84 words
A Hall effect device test circuit as claimed in claim 1, wherein said first indicating means is further operative to provide a gated operate-pass signal associated with said sensible operate-pass signal and further operative to provide a gated release-pass signal associated with said sensible release-pass signal, said Hall effect device test circuit further comprising: second indicating means connected to said first indicating means, and operative in response to said gated operate-pass signal and said gated release-pass signal to provide a sensible HED pass signal.
Claim 4
Dependent Claim 57 words
A Hall effect device test circuit as claimed in claim 1, wherein said first indicating means comprises: a first AND gate and a first light emitting diode connected thereto, and operative to provide said sensible operate-pass signal; and second AND gate and a second light emitting diode connected thereto, and operative to provide said sensible release-pass signal.
Claim 5
Dependent Claim 27 words
A Hall effect device test circuit as claimed in claim 2, wherein said second indicating means comprises: an AND gate and a light emitting diode connected thereto.
Claim 6
Dependent Claim 89 words
A Hall effect device test circuit as claimed in claim 1, wherein there is further included: second indicating means operative in response to said electrical signal of said first characteristic being either greater than said first predetermined digital signal or less than said second predetermined digital signal, to provide a sensible operate-fail signal; and further operative in response to said electrical signal of said second characteristic being either greater than said third predetermined digital signal or less than said fourth predetermined digital signal to provide a sensible release-fail signal.
Claim 7
Dependent Claim 85 words
A Hall effect device test circuit as claimed in claim 5, wherein said second indicating means is further operative to provide a gated operate-fail signal associated with said sensible operate-fail signal, and further operative to provide a gated release-fail signal associated with said sensible release-fail signal, said Hall effect device test circuit further comprising: third indicating means connected to said second indicating means, and operative in response to either said gated operate-fail signal or said gated release-fail signal to provide a sensible HED fail signal.
Claim 8
Dependent Claim 57 words
A Hall effect device test circuit as claimed in claim 6, wherein said second indicating means comprises: a first OR gate and a first light emitting diode connected thereto and operative to provide said sensible operate-fail signal; and a second OR gate and a light emitting diode connected thereto, and operative to provide said sensible release-fail signal.
Claim 9
Dependent Claim 27 words
A Hall effect device test circuit as claimed in claim 6, wherein said third indicating means comprises an OR gate and a light emitting diode connected thereto.
Claim 10
Dependent Claim 97 words
A Hall effect device test circuit as claimed in claim 1, wherein said comparison means comprises: a first binary comparator operative to compare said electrical signal of said first characteristic to said first predetermined digital signal; a second binary comparator operative to compare said electrical signal of said first characteristic to said second predetermined digital signal; a third binary comparator operative to compare said electrical signal of said second characteristic to said third predetermined digital signal; and a fourth binary comparator operative to compare said electrical signal of said second characteristic to said fourth predetermined digital signal.
Claim 11
Dependent Claim 229 words
A Hall effect device test circuit as claimed in claim 1, wherein said conversion means comprises: pulsing means connected to said Hall effect device and operative in response to said electrical signals of said first and second characteristics to provide pulsing signals of first and second characteristics; an analog-to-digital converter connected to said pulsing means and said sample voltage resistor and operative in response to said pulsing signal of said first characteristic and said sample voltage to provide a first digital signal, and further operative in response to said pulsing signal of said second characteristic and said sample voltage to provide a second digital signal; and further operative in response to each of said pulsing signals to provide a status signal; and gating means connected to said pulsing means and said analog-to-digital converter and operative in response to said pulsing signal of said first characteristic and said status signal to provide a first gating signal and further operative in response to said pulsing signal of said second characteristic and said status signal to provide a second gating signal; first and second storage means connected to said analog-to-digital conversion means and said gating means and operative in response to said first and second gating signals to store said digital signals of said first and second characteristics, respectively, and provide said first and second digital representations of said sample voltage, respectively.
Claim 12
Dependent Claim 99 words
A Hall effect device test circuit as claimed in claim 10, wherein there is further included third storage means connected between said pulsing means and said gating means and operative in response to said pulsing signals of said first and second characteristics to provide level signals of first and second characteristics, respectively; and said gating means operative in response to said status signal and said level signal of said first characteristic, and further operative in response to said status signal and said level signal of said second characteristic to provide said gating signals of first and second characteristics, respectively.
Claim 13
Dependent Claim 20 words
A Hall effect device test circuit as claimed in claim 11, wherein said third storage means comprises a latch circuit.
Claim 14
Dependent Claim 31 words
A Hall effect device test circuit as claimed in claim 10, wherein said pulsing means comprises first and second monostable miltivibrators operative to provide said first and second pulsing signals, respectively.
Claim 15
Dependent Claim 21 words
A Hall effect device test circuit as claimed in claim 1, wherein each of said threshold means comprises a dual-inline-package switch.
Claim 16
Dependent Claim 40 words
A Hall effect device test circuit as claimed in claim 10, wherein said first and second storage means comprises first and second groups of D-type flip-flops operative to provide said first and second digital representations of said sample voltage, respectively.

References Cited (Backward Citations)

US2979654A Cited
US3649912A Cited
US3614609A Cited
US4190799A Cited
US4230987A Cited
US4340861A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1988-01-01 1988-07-02 1989-01-01 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1992-01-01 1992-07-02 1993-01-01 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1996-01-01 1996-07-02 1997-01-01 $7700.00 Window Closed / Lapsed

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