Hall effect device test circuit
First Claim
1. 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.
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Accused Products
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.
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Citations
15 Claims
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1. A Hall effect device test circuit for use in a test system including a source of a power signal, said test circuit comprising:
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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; andfirst 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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Specification