Hall effect device test circuit
First Claim
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1. A Hall effect device test circuit for use in a test system including a power signal source, said test circuit comprising:
- magnetic field means connected to said power signal source, operated in response to said power signal to periodically provide a magnetic field of varying intensity;
voltage reference means connected to said power source, operated 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, operated in response to each magnetic field of a first predetermined intensity to provide an operate signal, and operated in response to each magnetic field of a second predetermined intensity to provide a release signal;
comparison means connected to said voltage reference means operated in response to said sample voltage having a magnitude less than a first predetermined threshold to provide a first comparison signal and further operated in response to said sample voltage having a magnitude greater than a second predetermined threshold to provide a second comparison signal;
storage means connected to said comparison means and said Hall effect device, operated in response to each operate signal and said first comparison signal to provide a first storage signal and further operated in response to each release signal and said second comparison signal to provide a second storage signal; and
signaling means connected to said storage means, operated in response to said first storage signal to provide a first status signal and further operated in response to said second storage signal to provide a second status signal.
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Abstract
A test circuit which detects Hall effect device operate and release time failures. This circuit includes a magnetic field circuit, a comparison circuit, a storage circuit and a visual indication circuit. The magnetic field circuit causes a Hall effect device under test to periodically switch states. The operate and release times of such switching is compared to predetermined thresholds by the comparison circuit. Switching times within the allowable thresholds cause the storage circuit to operate the visual indication circuit.
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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 power signal source, said test circuit comprising:
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magnetic field means connected to said power signal source, operated in response to said power signal to periodically provide a magnetic field of varying intensity; voltage reference means connected to said power source, operated 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, operated in response to each magnetic field of a first predetermined intensity to provide an operate signal, and operated in response to each magnetic field of a second predetermined intensity to provide a release signal; comparison means connected to said voltage reference means operated in response to said sample voltage having a magnitude less than a first predetermined threshold to provide a first comparison signal and further operated in response to said sample voltage having a magnitude greater than a second predetermined threshold to provide a second comparison signal; storage means connected to said comparison means and said Hall effect device, operated in response to each operate signal and said first comparison signal to provide a first storage signal and further operated in response to each release signal and said second comparison signal to provide a second storage signal; and signaling means connected to said storage means, operated in response to said first storage signal to provide a first status signal and further operated in response to said second storage signal to provide a second status signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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Specification