| 摘要 |
PURPOSE:To ensure stable oscillation regardless of the fluctuation of power supply voltage, by stabilizing the charge/discharge control of the capacitance of a CR circuit. CONSTITUTION:When a power supply VCC is applied to a capacitance C0 via a resistance R0, charging is carried out to increase voltage Va. When the voltage Va reaches the voltage VHT, a transistor TR1 is turned on. Then the divided voltage Vg at the joint between resistances R21 and R22 is equal to the voltage VCC, and a TR21 is turned off. At the same time, a TR23 of a control circuit 31 is turned on. As a result, the capacitance C0 is discharged to lower suddenly the voltage Va. When the Va lowers down to the voltage VLT, the TR1 is turned off. Thus the voltage Vg lowers to turn on the TR21 with the TR23 turned off, respectively. As a result, the capacitance C0 is charged to increase the voltage Va again. Thus the oscillation is performed. |
