Resonant circuit for increasing variable reluctance sensor output
First Claim
1. An apparatus that measures a characteristic of a machine, comprising:
- a variable reluctance sensor (VRS) coupled to said machine and operative to generate a basic output signal having a variable amplitude and a basic frequency representative of said characteristic; and
a first switching device electrically coupled to said VRS, operative to generate a modified output signal, and having a control input for receiving signals at a resonant frequency.
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Accused Products
Abstract
An apparatus and method for measuring a characteristic of a machine. A variable reluctance sensor (VRS) is coupled to the machine. A first switching device and capacitor, coupled in parallel with the VRS, boosts a variable amplitude of a basic output signal generated by the VRS to increase the signal-to-noise ratio. A control input of the first switching device receives signals, and a modified output signal is generated by the first switching device, having a variable amplitude that is substantially higher than the variable amplitude of the VRS. The modified output signal has an increased signal-to-noise ratio such that machine speed can be more accurately measured during a start-up phase.
6 Citations
17 Claims
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1. An apparatus that measures a characteristic of a machine, comprising:
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a variable reluctance sensor (VRS) coupled to said machine and operative to generate a basic output signal having a variable amplitude and a basic frequency representative of said characteristic; and
a first switching device electrically coupled to said VRS, operative to generate a modified output signal, and having a control input for receiving signals at a resonant frequency. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A method of measuring a characteristic of a machine having a variable reluctance sensor (VRS), comprising:
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generating a first output from said VRS having a variable amplitude and a basic frequency representative of said characteristic; and
generating a second output having a variable amplitude that is greater than said variable amplitude of said first output as the result of a charge stored in a charge storage device. - View Dependent Claims (10, 11, 12, 13, 14)
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15. A machine system, comprising:
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a machine having a camshaft with a speed wheel mounted thereon, said speed wheel including at least one gear tooth; and
a sensing system electrically coupled to said machine, said sensing system comprising, a variable reluctance sensor (VRS) adapted to detect a position of said gear tooth and to generate a basic output signal having a variable amplitude and a basic frequency representative of said position, a first switching device electrically coupled in parallel with said VRS, said first switching device generating a modified output signal and having a control input adapted to receive signals at a resonant frequency, and a charge storage device coupled in parallel with said first switching device and adapted to measure a voltage if said first switching device is in a first position, said charge storage device operative to boost a variable amplitude of said modified output signal to a level greater than said variable amplitude of said basic output signal. - View Dependent Claims (16, 17)
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Specification