Patent ID: 7612511

Claim:
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.