| 摘要 |
PURPOSE:To make it possible to prevent a forced air intake/exhaust unit type heating apparatus from malfunctioning by inhibiting the power from being supplied to a load within a constant time after the power is turned OFF, by controlling a electric discharge type time constant circuit composed of a resistance and capacitor connected to an anode. CONSTITUTION:With switch 2 opened, DC power supply 1 is disconnected and relay 10 is undriven, so that capacitor C3 will be discharged via resistance R5. At this time, even if switch 2 would be closed before charge comes into effect sufficiently, the anode potential of PUT6 is increased by the voltage of C3, and consequently PUT6 is disabled to turn ON, so that relay 10 will not be driven. The moment C3 is discharged sufficiently, it becomes possible to restart relay 10 for the first time. Additionally, the timer time of this circuit is determined by the time constant, the product of C3 and R5. |
