Load drive apparatus
First Claim
1. A load drive apparatus for driving a load with a power source comprising:
- first switch means for controlling supply of power from the power source to the load;
a noise filter including a coil and second switch means, the coil being connected in series between the power source and the load, and the second switch means being connected in parallel with, at least, part of the coil; and
a control circuit for driving the load by turning on or off the first switch means, the control circuit turning off the second switch means thereby to filter noise appearing on a power supply path including the coil, and the control circuit turning on the second switch means thereby to short-circuit, at least, a part of the coil between the power source and the load.
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Accused Products
Abstract
A load drive apparatus includes a noise filter, which includes a coil connected in series between a power source and a load, and a switching transistor connected in parallel across the coil, and a control circuit which is operated based on a drive signal. The control circuit turns on the switching transistor of the noise filter in case of subjecting the load to a full-on drive, thereby to short-circuit the coil and to form a power supply path including the switching transistor without the coil. The control circuit turns off the switching transistor of the noise filter in case of subjecting the load to a PWM drive, thereby to form a power supply path including the coil.
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Citations
7 Claims
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1. A load drive apparatus for driving a load with a power source comprising:
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first switch means for controlling supply of power from the power source to the load; a noise filter including a coil and second switch means, the coil being connected in series between the power source and the load, and the second switch means being connected in parallel with, at least, part of the coil; and a control circuit for driving the load by turning on or off the first switch means, the control circuit turning off the second switch means thereby to filter noise appearing on a power supply path including the coil, and the control circuit turning on the second switch means thereby to short-circuit, at least, a part of the coil between the power source and the load. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification