How do I: Convert 110vac to 90vdc

Discussion in 'The Projects Forum' started by Nevalist, Apr 12, 2015.

  1. Nevalist

    Thread Starter New Member

    Apr 12, 2015
    Desired final device: Floor sander
    Motor used: Johnson treadmill motor. Variable motor 90vdc max 15A max and drives are already built in.

    So friend had a treadmill his wife wanted gone and I have been thinking this for a while. I have been looking for AC motors like something off a compressor but this fell into my lap. I have read many articles for much lower voltages and almost no amperage. This topic isn't in my wheelhouse of expertise.

    A bit of background on me I am a heavy truck mechanic and fabricator. Building the housing for the sander and making the arm will literally take me an hour to cut and weld all of it together.

    The motor can be run up to 90v so the conversion doesn't have to be exact. And I would prefer the device to be variable to accommodate different uses. I would prefer this to be as simple as possible. If converting 110 to 110 is easier and to use a switch at different speeds i.e. a 4 speed switch where 25%, 50%, 75%, 100% power are delivered I would use it on 100%. But again not my wheelhouse. So if anyone knows or has built something like this please let me know.

    Thanks for reading.
  2. MaxHeadRoom


    Jul 18, 2013
    These T.M. motors are ran directly off of 120vac input supply, they generally use a DC SCR bridge type controller, these can be had on ebay made by KB & Baldor.
    The speed is adjustable via a 5k potentiometer.