| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce a cost and to save a space for a wiring without changing a rule of fail safe by a method wherein a signal transmitted through a communication line is compared with a source switch recognition signal and according to the comparing result, closing and breaking of a power source to a device are controlled. SOLUTION: A switch signal is inputted to an ECU 1 through one signal input wire W to effect processing of a signal. A system source control part 2 first decides it from an input signal (b) forming an L level whether press of a switch SW1 is effected and secondly decides it from a signal (a) forming an L level whether the main switch SW1 is pressed. A power source is controlled on that particular time when both the signals (a) and (b) are an L level. Further, when abnormality occurs in a signal processing part 4, the signal a always produces an H level. When the signal wire W is disconnected, a signal equivalent to a cancel switch S4 is inputted to the ECU 1, thereby ensuring safety of a device.</p> |
