DC Motor Query

Discussion in 'General Electronics Chat' started by Rapporman, Nov 3, 2012.

  1. Rapporman

    Thread Starter New Member

    Nov 3, 2012
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    I expect this query is a very simple one but not being electronically minded, I just do not know the answer and would appreciate your help.

    My query is that I have an electric golf trolley run by a DC motor and 12 volt battery. It has an "On" button that makes the system live and a "Start" button which then operates the variable speed motor and moves the trolley forward. The wheels incorporate a clutch system which enables the motor to move the trolley forward or allows me to push the trolley forward manually when the motor is turned off. However, there are numerous occasions when I have to pull the trolley backwards to, say, avoid an obstruction /casual water etc and when I do so I have time to turn off the motor but for expedience sake, I leave the system live.

    My query is :- Am I doing any damage to the motor when I pull the trolley backwards as mentioned above, bearing in mind the motor is not exactly operational but nevertheless turns in reverse when I pull it backwards. Would it make any difference if the system is on or off?

    Any advice would be much appreciated
     
  2. PackratKing

    Well-Known Member

    Jul 13, 2008
    850
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    Stab ----> :D I would guess, that the rheostat that allows you to advance under power, is at a "rest" phase when stopped, so do not really see how it would bother it to pull bkwds , since no forward current is being fed to the motor..........hope that made sense ............
     
  3. Rapporman

    Thread Starter New Member

    Nov 3, 2012
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    0
    Many thanks Patratking. From what you are saying I gather that a simple motor can be turned in both directions manually without damage, provided there is no current activating it. Unless I hear from you or anyone else to the contrary, I will assume that is the case.

    Thank you.:)
     
  4. praondevou

    AAC Fanatic!

    Jul 9, 2011
    2,936
    488
    You probably won't harm your motor. But if this is a permanent magnet DC motor it will generate a voltage when you turn it. If this can be harmful to your regulator I can not say from here.
    In theory a vehicle should have a device to deal with power generated from a drive motor.

    Anyways, if that was my trolley and I didn't want to waste time on this issue I would always make sure the motor doesn't turn when pushing/pulling the trolley manually.
     
  5. PackratKing

    Well-Known Member

    Jul 13, 2008
    850
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    Praondevou has a point.......as long as you are not trying to break landspeed records pushing bkwds...............and you really don't go bkwds that often ?? you should be ok.

    in the event it has belt drive... this isn't necessarily easy, one pulley or the motor shaft can be fitted w/ a one-way clutch..........tho' that is likely more involved than you want to get.
     
  6. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
    If there is a "free wheeling diode" that is always connected across the motor, it may cause dynamic braking when pushing in reverse.
     
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