DC motor PSU

Discussion in 'The Projects Forum' started by xf8u39, Jul 31, 2014.

  1. xf8u39

    Thread Starter New Member

    Jul 31, 2014
    2
    0
    Hi, I have a 200V DC motor, 1Hp 4.8A 2800rpm

    I would like to build a power supply for it.

    It's main use will be to drive motorcycle engines at upto 1000rpm on my test bench.

    I plan to rebuild plenty of engines in future and run them (without spark plugs) to check they are mechanically sound.

    Any ideas?

    Mike
     
  2. alfacliff

    Well-Known Member

    Dec 13, 2013
    2,449
    428
    that would be a 200 volt supply capable of around 4.67 amps continously, and have a high surge rating for startup. that would require a large transformer, some not so large rectifiers and such. its the startup current that will be the problem, why not go with an ac motor?
     
  3. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,510
    2,369
    Depending where you are located, you may want to look at one of the KB/Baldor DC drives on ebay, I have picked them up for as low as $15.00.
    The other way is a simple Triac controller and Bridge rectifier for control.
    With the Pot control you will not get an intially high current.
    Max.
     
  4. inwo

    Well-Known Member

    Nov 7, 2013
    2,433
    315
    I believe a 120vac-90vdc control, similar to what Max recommends will work for you. Baldor (or such) scr dc motor control.

    To see, just connect motor to 120vac thru a bridge. If you get enough speed and torque, you're good to go.

    If not, same advice, use the 240vac-180vdc out Baldor or similar, connected to 240V circuit or transformer.

    Depending on your junk pile, a variac thru a bridge will get an increase in voltage and very simple speed control. (that's what I do all the time for motor testing)
     
  5. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,510
    2,369
    Either way, an adjustable supply is needed if you want to control at a certain RPM, in any case it is not a good idea to place the motor directly across the 180dc due to the initial inrush current.
    Max.
     
  6. inwo

    Well-Known Member

    Nov 7, 2013
    2,433
    315
    Did pretty good.:D

    I suggested listening to Max, before he posted.

    He still beat me though!

    edit.
    I've thrown 180V motors across 120v+bridge without issue.
    Start with single diode if worried.
    The 1hp may be overkill is my thinking.
    Motor has to be solidly mounted of course.
     
    Last edited: Jul 31, 2014
  7. xf8u39

    Thread Starter New Member

    Jul 31, 2014
    2
    0
    Thanks for help guys. Just to give you more info. I am UK, so 220-240V mains
    Also, I will only be controlling the motor from zero to about 1000rpm so the surge of current will not be an issue.
    It will never be run flat out i.e max speed and torque.

    Please attach any links you see fit to point me in the right direction.

    Mike
     
  8. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,510
    2,369
    Last edited: Jul 31, 2014
  9. alfacliff

    Well-Known Member

    Dec 13, 2013
    2,449
    428
    another source of small ac and dc drives is dart controls available from the granger catalog here and has a uk distributor on their web page.
     
Loading...