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How to control motor using ESC, Ardiuno, and a potentiometer

  1. Jun 11, 2013 #1
    So I want to build an electric longboard. I have access to pretty much any machining equipment but don't have much knowledge on the electrical side of things. I know I will need a LiPo battery (I am aware of the dangers of them), and an electronic speed controller (ESC) hooked up to the motor. I am thinking of putting in an Arduino to control the motor (using a wired potentiometer) using PWM signal to make the acceleration smoother.

    But I am unaware of all the different specs on these I would need. Also, how would I be able to brake using this configuration? because I know there is a way.

    I am thinking of using these following things:
    motor: http://www.hobbyking.com/hobbyking/store/__22036__NTM_Prop_Drive_50_60_270KV_2400W.html

    ESC: http://www.hobbyking.com/hobbyking/store/__18014__HobbyKing_Red_Brick_125A_ESC_Opto_.html [Broken]

    Battery: http://www.hobbyking.com/hobbyking/store/__8586__ZIPPY_Flightmax_5000mAh_6S1P_25C.html



    Thanks for the help
     
    Last edited by a moderator: May 6, 2017
  2. jcsd
  3. Jun 12, 2013 #2
    I'm not quite sure what an "ESC" does, even after skimming over the manual. I think it may translate "hobby servo" PWM signals to speed control for larger motors. If that's the case you may only need a variable pulse width oscillator (maybe made from at 555 chip) or commercial hobby servo controller and can skip the arduino bit entirely.

    But the thing that jumps out is that your motor is speced for 30V at 90A (max) and your battery is 22.5V at 5Ah. So you will be able to go about 10 feet before the battery is discharged... The AmpHour rating is usually how many amps you can get out of the battery when discharged over a period of 20hours and you generally want to use less than half that rating to extend the battery recharge life.
     
  4. Jun 13, 2013 #3
    The ESC - is usually just a DC chopper, unless it has directional control then it is a Full (H) bridge. The issue with breaking is that you need the ESC to pass current back to something ( Resistor, Capacitors or the battery) - typically hobby set ups are not made to do that. The MOSFETs in the ESC have a body diode that will let the current go from the motor back to the battery, but the battery probably will not want to absorb that much energy that fast - you may see an overvoltage - and blow the ESC - they are very voltage sensitive. I would suggest looking for a broken electric razor scooter (craigslist)- it has the same elements, and hacking into it and see what you can learn...
    Oh the arduino does have a motor controller shield - both its design and the code to run it will be open source.
     
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