Electronic speedometer calibration device
First Claim
1. A method of correcting the speed displayed on an electronic speedometer, comprising the steps of:
- (a) determining a multiplication factor;
(b) obtaining an electrical speed signal from a motor vehicle drive system;
(c) multiplying a frequency of said electrical speed signal by said multiplication factor to produce a modified electrical speed signal; and
(d) inputing said modified electrical speed signal into the electronic speedometer.
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Accused Products
Abstract
An electronic speedometer calibration device includes a microcontroller and an entry device. The microcontroller receives an electrical speed signal from the speed sensor. The microcontroller is instructed to change the frequency of the electrical speed signal by some multiplication factor. The multiplication factor may be entered through a keypad, a computer download, or through any other suitable device. The multiplication factor is preferably shown on a display device. The multiplication factor may be greater than or less than one. The microcontroller will output an electrical speed signal to the electronic speedometer with a frequency which has been modified by the multiplication factor. The speedometer will display the corrected speed. A second embodiment of the electronic speedometer calibration device includes a digital frequency multiplier and a digital frequency divider. A third embodiment of the electronic speedometer calibration device includes a frequency to voltage converter, variable gain amplifier, and voltage to frequency converter.
8 Citations
12 Claims
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1. A method of correcting the speed displayed on an electronic speedometer, comprising the steps of:
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(a) determining a multiplication factor;
(b) obtaining an electrical speed signal from a motor vehicle drive system;
(c) multiplying a frequency of said electrical speed signal by said multiplication factor to produce a modified electrical speed signal; and
(d) inputing said modified electrical speed signal into the electronic speedometer.
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2. The method of correcting the speed displayed on an electronic speedometer, further comprising:
a microcontroller receiving said electrical speed signal, said microcontroller multiplying the frequency of said electrical speed signal by said multiplication factor, said microcontroller outputing said modified electrical speed signal.
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3. The method of correcting the speed displayed on an electronic speedometer, further comprising:
a frequency multiplier receiving said electrical speed signal and multiplying the frequency thereof by a multiplication factor, said output of said frequency multiplier being input into a frequency divider, said frequency divider dividing said output of said frequency multiplier to produce said modified electrical speed signal.
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4. The method of correcting the speed displayed on an electronic speedometer, further comprising:
a frequency to voltage converter receiving said electrical speed signal, a variable gain amplifier inputing a proportional voltage from said frequency to voltage converter, a voltage to frequency converter receiving the output of said variable gain amplifier, said voltage to frequency converter outputing said modified electrical speed signal.
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5. An electronic speedometer calibration device comprising:
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a microcontroller receiving an electrical speed signal from a motor vehicle drive system; and
an entry device capable of entering a multiplication factor into said microcontroller, said microcontroller multiplying the frequency of said electrical speed signal by said multiplication factor to produce a modified electrical speed signal, an electronic speedometer receiving said modified electrical speed signal. - View Dependent Claims (6, 7, 8)
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9. An electronic speedometer calibration device comprising:
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a frequency multiplier receiving an electrical speed signal from a motor vehicle and multiplying the frequency thereof by a multiplication factor; and
a frequency divider receiving the output of said frequency multiplier and dividing the frequency thereof by a dividing factor to produce said modified electrical speed signal for input into an electronic speedometer. - View Dependent Claims (10)
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11. An electronic speedometer calibration device comprising:
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a frequency to voltage converter receiving an electrical speed signal from a motor vehicle drive system, said frequency to voltage converter outputing a proportional voltage;
a variable gain amplifier inputing said proportional voltage and multiplying thereof by a set value of gain; and
a voltage to frequency converter receiving the output of said variable gain amplifier and outputing a modified electrical speed signal for input into an electronic speedometer. - View Dependent Claims (12)
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Specification