| 摘要 |
PROBLEM TO BE SOLVED: To provide a circuit for generating control signals at the point of time at which prescribed time elapses from the rise of an input voltage by simple constitution after power supply turned on. SOLUTION: A transistor Q1 is provided to be conductive when the output voltage of a power source circuit 11 becomes a prescribed voltage in response to it and charging and discharging to/from the capacitor C of a time counting circuit 13 constituted of a resistor R4 and the capacitor C are controlled by the transistor Q2 further. Then, the transistor Q2 is controlled by the transistor Q1, the capacitor C is charged by the transistor Q2 when the transistor Q1 becomes conductive and the capacitor C is discharged when the transistor Q1 is off. Since the rise of an input power source is detected based on the output voltage of the power source circuit 11, that is a constant voltage, it is not required to newly generate a constant voltage for detecting the rise of the input power source.
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