| 摘要 |
PURPOSE:To reduce the extent of power consumption as well as to prevent a power source from coming into uproarious and dangerous conditions due to wrong operation, by letting a power controlling device stop a power supply to a car-mounted machine from the power source at a time when a car is in a running state and there is no burglarious warning state. CONSTITUTION:A burglar alarm control circuit is constituted of a burglar alarm controlling microcomputer 10. And, a terminal of an ignition coil 26 is connected to one input of a comparator 38, and output of this comparator 38 is connected to a base of a transistor 40, therefore, it is L at driving but H at stoppage. When a car is in a running state and unalarmingness, both bases of transistors 40 and 42 are L and both are off whereby a transistor 44 is off, thus a power supply to the burglar alarm controlling microcomputer 10 from a power source is stopped. |
