Oil deterioration detection apparatus
First Claim
1. An oil deterioration detection apparatus comprising:
- a sensor that detects a characteristic of oil and produces a characteristic signal;
a malfunction detecting circuit that has a switch connected in parallel with the sensor;
an evaluation circuit that evaluates whether the oil is deteriorated based on the characteristic signal, which is detected when the switch is opened so that the malfunction detecting circuit is not electrically conducted in parallel with the sensor; and
a determination circuit that determines whether the sensor malfunctions based on the characteristic signal, which is detected when the switch is closed so that the malfunction detecting circuit is electrically conducted in parallel with the sensor;
wherein the switch connects the malfunction detecting circuit in parallel with the sensor in a time period, and disconnects the malfunction detecting circuit from the sensor in another time period.
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Accused Products
Abstract
An oil deterioration detection apparatus includes a sensor, an evaluation circuit, and a malfunction detecting circuit. The evaluation circuit has a determination circuit. The malfunction detecting circuit has a resistor and a switch. The evaluation circuit evaluates a condition of the oil based on a normal voltage. The normal voltage is measured when the switch is opened so that the resistor is not electrically conducted. The determination circuit determines whether the sensor malfunctions based on a relation between the normal voltage and a divided voltage. The divided voltage is measured when the switch is closed so that the resistor is electrically conducted in parallel with the sensor.
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Citations
20 Claims
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1. An oil deterioration detection apparatus comprising:
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a sensor that detects a characteristic of oil and produces a characteristic signal; a malfunction detecting circuit that has a switch connected in parallel with the sensor; an evaluation circuit that evaluates whether the oil is deteriorated based on the characteristic signal, which is detected when the switch is opened so that the malfunction detecting circuit is not electrically conducted in parallel with the sensor; and a determination circuit that determines whether the sensor malfunctions based on the characteristic signal, which is detected when the switch is closed so that the malfunction detecting circuit is electrically conducted in parallel with the sensor; wherein the switch connects the malfunction detecting circuit in parallel with the sensor in a time period, and disconnects the malfunction detecting circuit from the sensor in another time period. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method of detecting oil deterioration, the method comprising:
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detecting a characteristic of oil and producing a characteristic signal via a sensor; providing a malfunction detecting circuit that has a switch connected in parallel with the sensor; evaluating whether the oil is deteriorated based on the characteristic signal detected when the switch is opened so that the malfunction detecting circuit is not electrically conducted in parallel with the sensor; and determining whether the sensor malfunctions based on the characteristic signal detected when the switch is closed so that the malfunction detecting circuit is electrically conducted in parallel with the sensor; wherein the switch connects the malfunction detecting circuit in parallel with the sensor in a time period and disconnects the malfunction detecting circuit with the sensor in a separate time period so that oil deterioration evaluation and sensor malfunction detection can be performed in separate time periods. - View Dependent Claims (17, 18, 19, 20)
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Specification