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, whereinthe coil includes a first coil and a second coil connected in series to each other;
the first switch means includes an inverter circuit; and
the control circuit drives the load by either a full-on drive or a switching drive based on a drive signal applied from an external side;
the control circuit turns on the second switch means to short-circuit the second coil and provide a power supply path that includes only the first coil, and performs a full-on drive of the load by the inverter circuit, so that the load is full-on driven; and
the control circuit turns off the second switch means to provide a power supply path that includes both the first coil and the second coil, and performs a switching drive of the load by the inverter circuit, so that the load is switching driven.
1 Assignment
0 Petitions
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.
11 Citations
6 Claims
-
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, wherein the coil includes a first coil and a second coil connected in series to each other; the first switch means includes an inverter circuit; and the control circuit drives the load by either a full-on drive or a switching drive based on a drive signal applied from an external side; the control circuit turns on the second switch means to short-circuit the second coil and provide a power supply path that includes only the first coil, and performs a full-on drive of the load by the inverter circuit, so that the load is full-on driven; and the control circuit turns off the second switch means to provide a power supply path that includes both the first coil and the second coil, and performs a switching drive of the load by the inverter circuit, so that the load is switching driven. - View Dependent Claims (2, 3, 4, 5, 6)
-
Specification