SER-1 fan speed controllers have an emergency button to activate smoke extraction (full speed). They control the speed of single phase voltage controllable motors with a maximum current of 7,5 A. The AC fan speed is regulated by varying the motor voltage in steps. The smoke extraction can also be activated via the digital input.
.jpg "Fan speed controller with smoke extraction")
.jpg "5-step fan speed controller with emergency smoke extraction")
.jpg "Emergency smoke extraction AC fan speed controller")