| 摘要 |
This invention relates to a ventilator wherein an electronic circuit is actuated when a detecting element detects the existence of any smoke or gas while a fan is in a manually selected slow rotating node of operation or in a stand-by halting position, and then the fan is automatically put into full rotation in order to expel smoke or such gas as carbon monoxide, and also for a specified period after completion of this expelling operation the fan is kept rotating during the above operation through the function of a delay-off circuit, with a shutter of a ventilating window being kept open by means of a switch network. |
