| 摘要 |
<p>PURPOSE:To simplify the constitution of a circuit, to easily select parts and to precisely initialize a microcomputer even at the time of instantaneous service interruption by constituting the device of a voltage detector, a counter and a gate without using a time constant circuit consisting of a resistor and a capacitor. CONSTITUTION:When an output voltage Va exceeds a voltage V2 at time T2, a transistor (TR) 11 in the voltage detector 8 is turned on, the output of a terminal 17 is changed to zero potential ('L' level) and a reset terminal 18b is turned to the 'L' level, so that the counter 18 is turned to the operating state. On the other hand, a clock pulse generator 3 starts oscillating operation prior to the time T2 when the voltage Va reaches the V1 and clock pulses are applied to an input terminal of the counter 18 through an AND gate. Since the counter 18 is reset up to the time T2, the clock pulses are not counted yet and the counting of clock pulses is started immediately after the time T2.</p> |
