| 摘要 |
PURPOSE:To realize space saving by preventing in advance an event that a load control function is lost even a short circuit takes place to a power supply line to sensors. CONSTITUTION:A voltage reply means 16 includes a transistor(TR) 17 interposed between a power supply terminal 11a connecting to an onvehicle battery and a power supply line PL, adjusts an output voltage Vp of the power supply line PL equal to an output voltage (5V) of a power supply IC 14 and turns off the TR 17 by inverting an output of an operational amplifier 19 when the output voltage gets higher than 5V. A TR 24 is turned on when both comparators 25, 26 output a high level signal to turn off the TR 17. The comparator 25 outputs a high level signal when an output voltage Vp is drops to OV, and the comparator 26 is latched to output a high level signal by a voltage signal Vd outputted from a CPU 15 in the normal state. |
