| 摘要 |
<p>PURPOSE:To execute a program normally all the time by initializing a computer securely at adequate time after power is turned OFF in case of a momentary power failure or power break of a controller using a one-chip microcomputer. CONSTITUTION:Between the power input terminal of constant-volgate circuit PS supplying power to one-chip microcomputer MCON and MCON, voltage detection circuit CCT1 is connected. This voltage detection circuit CCT1 absorbs variation in input to constant-voltage circuit PS and detects voltages across a rectifier circuit and smoothing circuit approximating to a regulation start voltage, and the output of voltage detection circuit CCT1 turns transistor TrQ4 ON to discharge capacitor C1. Then, a potential at terminal INIT of MCON is nearly equalized to voltage Vss within fixed time to obtain fixed characteristics as to a rise when power supply AC100V is turned ON, and MCON is initialized to executing a program in a normal state all the time.</p> |
