Input circuit for inductive engine speed sensor
First Claim
1. An input circuit for receiving and processing signals from an inductive speed sensor, comprising:
- a comparator;
a switchable voltage divider which includes first and second resistors; and
first and second circuit inputs each of which is connected to an input of the comparator for evaluating signals from the inductive speed sensor and to the switchable voltage divider;
wherein the first circuit input is connected via the first resistor to a first input of the comparator, and the second circuit input is connected via the second resistor, which is disconnectable by a switching device, to the first input of the comparator as well;
the switching element is switchable, depending on speed detected by the speed sensor such that, if the speed value is above a predetermined speed, the second resistor is connected, and, if the speed value is below the predetermined speed, the second resistor is disconnected from the second circuit input.
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Accused Products
Abstract
A circuit for inputting and processing a signal from a speed sensor element, includes a comparator having first and second input terminals and first and second input circuits connected to receive the signal. The first input circuit is connected to a first input terminal of said comparator, and the second input circuit is connected to a reference voltage and to the second input terminal of said comparator. A switchable voltage divider circuit interruptibly connecting a voltage divider circuit for reducing an amplitude of the signal on said first input circuit; and a microprocessor is connected to receive and process an output of the comparator and to determine a speed value based thereon. The microprocessor controls switchable voltage divider based on the magnitude of determined vehicle speed.
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Citations
9 Claims
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1. An input circuit for receiving and processing signals from an inductive speed sensor, comprising:
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a comparator;
a switchable voltage divider which includes first and second resistors; and
first and second circuit inputs each of which is connected to an input of the comparator for evaluating signals from the inductive speed sensor and to the switchable voltage divider;
whereinthe first circuit input is connected via the first resistor to a first input of the comparator, and the second circuit input is connected via the second resistor, which is disconnectable by a switching device, to the first input of the comparator as well;
the switching element is switchable, depending on speed detected by the speed sensor such that, if the speed value is above a predetermined speed, the second resistor is connected, and, if the speed value is below the predetermined speed, the second resistor is disconnected from the second circuit input. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A circuit for inputting and processing a signal from a speed sensor element, comprising:
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a comparator having first and second input terminals;
first and second input circuits connected to receive said signal, said first input circuit being connected to a first input terminal of said comparator, and said second input circuit being connected to a reference voltage and to said second input terminal of said comparator;
a switchable voltage divider circuit interruptible connecting a voltage divider circuit for reducing an amplitude of the signal on said first input circuit; and
a microprocessor connected to receive and process an output of said comparator and for determining a speed value based thereon;
wherein said microprocessor controls switching said switchable voltage divider based on a magnitude of determined vehicle speed.
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Specification