Field coil fault detector for automotive alternator battery charging systems
First Claim
1. In a multiphase alternator and voltage regulator battery charging system, said alternator having a field coil and diode connected in a parallel circuit, said voltage regulator supplying excitation current to said field coil in response to a detected system voltage, a detector monitoring the operational status of said field coil circuit comprising:
- means monitoring a first signal at a first terminal of said field coil circuit;
means generating sampling intervals on a repetitive basis;
means coupled to said voltage regulator and responsive to said sampling means, for interrupting said excitation signal supplied by said voltage regulator to said field coil circuit during sampling intervals;
means coupled to a second terminal of said field coil circuit and operative only during said sampling intervals to measure a second signal in said circuit; and
comparator means comparing said first and second signals producing an output signal when said comparison varies from a predetermined value.
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Accused Products
Abstract
A detector monitoring the operational status of the field coil circuit in a multiphase alternator and voltage regulator battery charging system is disclosed. Circuit means monitor a first signal at a first terminal of the field coil circuit. Means generate sampling intervals on a repetitive basis. Circuit means interrupt the excitation signal supplied to the field coil by the voltage regulator during the sampling intervals. A second signal is measured during sampling intervals at a second terminal of the field coil circuit. Comparator means compare the first and second signals and produce an output signal when the comparison varies from a predetermined value.
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Citations
7 Claims
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1. In a multiphase alternator and voltage regulator battery charging system, said alternator having a field coil and diode connected in a parallel circuit, said voltage regulator supplying excitation current to said field coil in response to a detected system voltage, a detector monitoring the operational status of said field coil circuit comprising:
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means monitoring a first signal at a first terminal of said field coil circuit; means generating sampling intervals on a repetitive basis; means coupled to said voltage regulator and responsive to said sampling means, for interrupting said excitation signal supplied by said voltage regulator to said field coil circuit during sampling intervals; means coupled to a second terminal of said field coil circuit and operative only during said sampling intervals to measure a second signal in said circuit; and comparator means comparing said first and second signals producing an output signal when said comparison varies from a predetermined value. - View Dependent Claims (2, 3, 4, 5, 6)
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7. The method of detecting the operational status of the field coil circuit in an alternator and voltage regulator battery charging system comprising the steps of:
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monitoring a first signal at a first terminal of the field coil circuit; generating sampling intervals on a repetitive basis; interrupting, during sampling intervals, the excitation signal supplied to said field coil circuit by said voltage regulator; measuring during said sampling intervals a second signal at a second terminal of said field coil circuit; and comparing said first and second signals and producing an output signal when the comparison varies from a predetermined value.
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Specification