PWM control of an EBM-Pabst G1G170-AB05-20

Discussion in 'The Projects Forum' started by fuzer_guy, Oct 27, 2011.

  1. fuzer_guy

    Thread Starter New Member

    Oct 26, 2011
    Howdy Everyone,

    I need to computer-control an EBM-Pabst G1G170-AB05-20 electric motor. The spec sheet
    contains a circuit diagram for the control on page 4. The fan itself runs on AC plugged into the wall, but the control circuit is a 2-6 kHz PWM signal with an amplitude of ~30V.

    Right now the best option I have for the actual computer control is using a 0-5V output on a NI USB-6009 using labview. That part is covered.

    For the actual analog voltage to PWM control I picked up a kit at my local electronics shop.

    I will have to amplify my 5V output voltage to range between 5-15V for the control signal (I plan to use an op amp, will cover that later), and I will have to modify the components from the kit I purchased to output the proper PWM frequency (I am shooting for around 3 kHz) using the formula provided by the manufacturer.

    I have included a schematic of how I would wire this once the PWM control is complete. The input/output "ports" on the PWM in my schematic match the available input/outputs according to the kit I bought.

    My question, will this work with my setup?

    I know there are many threads on the PWM, but all of them appear to be for direct control of the motor (i.e. a DC motor), and the person at the electronics store indicated that a control frequency of 2-6 kHz was beyond normal.

    *Edit* To clarify, the motor runs at full speed without any PWM control. Also, I have attached another diagram with a setup I tried recently just to see if I was on the right track. The function generator was set to output a 3kHz square wave at 50% duty cycle. I then connected it as shown. That really didnt work.. the wires connecting the 40V supply to the system melted ><
    Why didnt it work? And the motor still works so I guess it didnt do any permanent damage to anything except my alligator clips.
    *End Edit*

    Thank you for reading, I look forward to your replies/additional questions.
    Last edited: Oct 27, 2011