| 摘要 |
PURPOSE:To enable to start operation from the initial condition even after a quick change is operated in a contact point, by inserting a resistor, a transistor, and a Zener diode between a capacitor and a resistor in a constant voltage circuit, in the titled device having timer ICs for setting the operation time and the stopping time for a ventilating fan. CONSTITUTION:When a changing switch contact point 3 is turned off and on quickly to contact it with the side 4, the smooth all waves rectifying voltage is generated by a transistor 8, a diode bridge 9 and a capacitor 10. If the voltage generated is higher than the Zener voltage of a Zener diode 46, the Zener diode 46 and a transistor 45 are charged with electricity, and the direct current voltage is applied to the ICs 20 and 29 in timer circuits, so that timers 20 and 29 are brought into operation. If the changing switch contact point 3 is contacted with the side 5, the voltage of capacitor 10 is gradually lowered, until the voltage of timer ICs 20 and 29 comes down to OV. After that, if the contact point 3 is quickly contacted with the side 4, the capacitor 10 is turned into a charged condition in the middle of discharging. But operation can be started from the initial condition, because the timer ICs 20 and 29 are in OV. In such a manner, a ventilating fan can be started from the initial condition without fail. |
