Motor Speed Control Circuit
First Claim
Patent Images
1. A motor speed control circuit comprising:
- a voltage generating circuit configured to output a reference voltage corresponding to a target rotation speed of a motor and a speed voltage corresponding to a rotation speed of the motor, and change either the reference voltage or the speed voltage according to a temperature;
a comparison circuit configured to compare the speed voltage with the reference voltage; and
a driving circuit configured to drive the motor so as to match a level of the speed voltage to a level of the reference voltage, based on a comparison result from the comparison circuit.
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Abstract
A motor speed control circuit includes: a voltage generating circuit configured to output a reference voltage corresponding to a target rotation speed of a motor and a speed voltage corresponding to a rotation speed of the motor, and change either the reference voltage or the speed voltage according to a temperature; a comparison circuit configured to compare the speed voltage with the reference voltage; and a driving circuit configured to drive the motor so as to match a level of the speed voltage to a level of the reference voltage, based on a comparison result from the comparison circuit.
22 Citations
14 Claims
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1. A motor speed control circuit comprising:
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a voltage generating circuit configured to output a reference voltage corresponding to a target rotation speed of a motor and a speed voltage corresponding to a rotation speed of the motor, and change either the reference voltage or the speed voltage according to a temperature; a comparison circuit configured to compare the speed voltage with the reference voltage; and a driving circuit configured to drive the motor so as to match a level of the speed voltage to a level of the reference voltage, based on a comparison result from the comparison circuit.
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2. A motor speed control circuit comprising:
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a reference voltage circuit configured to output a reference voltage corresponding to a target rotation speed of a motor and a temperature, based on a speed control signal corresponding to the target rotation speed and a temperature signal corresponding to the temperature; a comparison circuit configured to compare a speed voltage corresponding to a rotation speed of the motor with the reference voltage; and a driving circuit configured to drive the motor so as to match a level of the speed voltage to a level of the reference voltage, based on a comparison result from the comparison circuit, the reference voltage circuit outputting the reference voltage at a predetermined level when the speed control signal for minimizing the target rotation speed of the motor is input.
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3. A motor speed control circuit comprising:
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a first current generating circuit configured to generate a first current corresponding to a target rotation speed of a motor based on a speed control signal corresponding to the target rotation speed; a second current generating circuit configured to generate a second current corresponding to a temperature based on a temperature signal corresponding to the temperature; a third current generating circuit configured to generate a third current corresponding to a product of the first current and the second current; a current-to-voltage conversion circuit configured to convert the third current to a reference voltage; a comparison circuit configured to compare a speed voltage corresponding to a rotation speed of the motor with the reference voltage; and a driving circuit configured to drive the motor so as to match a level of the speed voltage to a level of the reference voltage, based on a comparison result from the comparison circuit. - View Dependent Claims (4, 5, 6, 7, 8)
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9. A motor speed control circuit comprising:
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a speed voltage circuit configured to output a speed voltage corresponding to a rotation speed of a motor and a temperature, based on a speed signal corresponding to the rotation speed and a temperature signal corresponding to the temperature; a comparison circuit configured to compare a reference voltage corresponding to a target rotation speed of the motor with the speed voltage; and a driving circuit configured to drive the motor so as to match a level of the speed voltage to a level of the reference voltage, based on a comparison result from the comparison circuit. - View Dependent Claims (10, 11, 12, 13, 14)
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Specification