| 摘要 |
PURPOSE:To eliminate useless operation or the continuance of ventilating operation to be carried out even after a satisfactorily ventilated state is available by operating automatically a ventilating fan interlocked with the operation of a lighting switch after having left a room and halting the operation of said ventilating fan in automatic mode after a preset time has lapsed. CONSTITUTION:When it is light indoors during daytime, a photoelectric switch EE is turned off so that electric current may not flow to a relay M2. As a result, a constantly open contact a21 remains under an off-state and a lighting device L will not light up. On the other hand, the constantly open contact b1 of the relay M1 is under an off-state by turning on a switch S, which halts the operation of a ventilating fan F. When having left a room, the switch S is turned off by manipulating the knob of a door so that a constantly open contact a12 of the relay M1 may be kept under an off-state, thereby putting out the lighting device L. On the other hand, a constantly open contact a11 is turned in an off-state, but a timer means T maintains a constantly open contact at under an on-state during preset time. By turning off the switch S, the constantly open contact b1 returns to the off-state so that the ventilating fan may be operated while it may be suspended after the preset time is over. |
