Being a programmer just getting started with electronics, I'm wanting to control the speed of an EC fan. They should be very easy to control from what I understand, but I'm not sure how to do it from Arduino.
The unit has a potentiometer which the manufacturer suggests to replace to control the speed. There is not much info on the unit. (Söderman EC100) The info I did find is a swedish PDF, but with English wiring diagram: http://www.soliduct.com/redirect.php?action=url&goto=delat.ws%2Fdownload%2FC-Instruction+manual+for+EC.pdf
The wiring diagram shows three wires used for speed control. 1. Labeled "UN (+)", and is currently connected to 10v on pot. 2. Labeled "PWM" and currently connected to "ADJ" on pot. 3. Ground
It seems like most ec motors offer the ability to control speed either with variable voltage or PWM, but looking at a few datasheets I can't see any requirements for the PWM signal other than details about duty cycles. Should one assume that the voltage needed for PWM control would be 10v? It seems like I'm missing something that would be inferred by some basic knowledge :blush:
Would it be possible to simply connect a PWM pin on the arduino directly to the PWM input? Since it is only a control signal, and the motor is driven by 220v, I'm guessing the voltage should not matter that much as long as the signal is strong enough to pick up the duty cycles?