Patent ID: 8144447

Claim:
A load controller for controlling an electromagnetic load, said load controller comprising: a power supply for supplying power to the electromagnetic load; a driver for the electromagnetic load, said driver being disposed between the electromagnetic load and at least one of the power supply and ground; and diagnosing means for diagnosing a fault in a circuit configuration by detecting a voltage abnormality between the electromagnetic load and driver; wherein, interruption and energization of the electromagnetic load are performed repeatedly; timing of detection of voltage abnormality is set to synchronize with energization start timing of the electromagnetic load; the load controller further includes a first current source controller for rapidly attenuating counter electromotive energy that is generated at a time of interruption of the electromagnetic load; the first current source controller is located between a position at which a jumping voltage is generated by the counter electromotive energy and ground, in parallel with a current source of a second current source controller that causes a current in the electromagnetic load to converge to and remain at, a given level; and the electromagnetic load controller further includes switching means for switching the first current source controller and the current source according to a given voltage threshold.