Electrical load driving apparatus

摘要

The electrical load driving apparatus includes means for alternately lowering the gate voltages of two current supply transistors connected in parallel to each other at regular time intervals, a current being supplied to an electrical load through drain-source paths of both the current supply transistors, and means for detecting wire breakage in two current supply wires in which the current supply transistors are interposed respectively at portions opposite the electrical load with respect to the current supply transistors based on the drain-source voltages of the current supply transistors.

主权项

1. An electrical load driving apparatus comprising:
a plurality of current supply wires connected in parallel with one another, each of the current supply wires being connected to one of a high side terminal and a low side terminal of a power source at one end thereof, and being connected to one end of an electrical load at the other end thereof, the other end of the electrical load being electrically connected with the other end of the high side terminal and the low side terminal of the power source; a plurality of current supply transistors each having one control terminal and two output terminals, each of the current supply transistors being interposed in a corresponding one of the current supply wires at the two output terminals to supply a current to the electrical load when being turned on during a current supply period in which the electrical load is supplied with the current continuously; a check period generating means for generating, within the current supply period, a check period in which all of the current supply transistors are turned on in a low current supply performance state where a voltage difference between the two output terminals of each of the current supply transistors is higher than or equal to a predetermined voltage; and a wire breakage determination means connected to the two output terminals of each current supply transistor to detect whether or not the voltage difference between the two output terminals of any one of the current supply transistors is lower than the predetermined voltage, and determine, upon detecting that the voltage difference between the two output terminals of one of the current supply transistors is lower than the predetermined voltage, that the current supply wire interposed by the detected current supply transistor is broken at an opposite load side portion thereof located on the opposite side of the detected current supply transistor with respect to the electrical load.