| 摘要 |
<p>PURPOSE:To suppress the malfunction of a system at the time of resetting, by setting forcibly an interface means which receives directly an output of a main control means, to the inactive state for a prescribed time from the time when an electric power source is turned on or the system is reset. CONSTITUTION:When an electric power source switch 3 is turned on, an electric power source for an electronic circuit, which is smoothed by a capacitor 27 through an electric power source transformer 5 and diodes 6, 7 is aroused. A constant-voltage circuit CV supplies DC constant-voltage to a main control means MCU46. Rise of power supply voltage of the MCU46 is not attained instantaneously, but a time delay is generated. On the other hand, voltage of a resetting circuit RE also rises slowly. A Zener diode 37 does not conduct until reaching breakdown voltage, and a transistor 45 remains off. Accordingly, a ground terminal 43T of a driving circuit 43 being an interface means is in a floating state, and is set forcibly to the inactive state. Therefore, a control signal of malfunction of the MCU46 is not transferred to loads 9, 16 and 20.</p> |
