| 摘要 |
PURPOSE:To obtain a reset pulse regardless of a gentle rise of voltage during application of power supply, by actuating a switching element with a difference between the signal that answers to the controlling reference voltage source of an output voltage control transistor of a voltage stabilizing circuit and the signal that answers to the output of the said stabilizing circuit. CONSTITUTION:When a power supply switch SW1 is turned on, capacitors C4 and C2 start charging by a power source E. Then the collector voltage and the base voltage of a transistor TRQ1 rise, and later the emitter voltage reaches the maximum level to be applied to the emitter of a TRQ2. At the same time, the voltage obtained at the point of connection between a Zener diode D4 and a diode D3 is applied to the base of the TRQ2. When the emitter voltage of the TRQ2 rises up to a level that is sufficiently higher than the base voltage, the TRQ2 switches to on from off. Thus, a differential pulse can be obtained at an output terminal A of a differentiating circuit. |
