... hall-free, power,etc.Applications: External rotor motor, centrifugal fan, centrifugal blower, axial fan in HVAC,Tele-communication, refrigeration, clean room, IT industry ... of Brushless DC Fan Motor speed controller:DC and EC Centrifugal fan, DC and EC axial fan, DC and EC circular duct fan, EC Gas ... EC motor, energy saving motor,etc. Low noise 48V BLDC Fan motor driver or controller with tach output