treadmill motor controller problem?

Discussion in 'General Electronics Chat' started by toki111, Aug 25, 2012.

  1. toki111

    Thread Starter New Member

    Aug 25, 2012
    8
    0
    hi all

    i'm hoping one of the electronic gods on here can guide me to solve a problem with a tredmill :)

    i'm not very knowledgeable as you's about electronics, but i know the basic stuff....an i'm a trier, an electronics has always fascinated me...

    ok the problem...

    the treadmill just stopped working, it had blown the internal fuse on the MCB...i replaced the fuse an it blow again.

    i disconnect the motor (180dc) an tried it with a car battery an it turns ok....then i noticed with the motor unplugged the fuse did not blow, but as soon as you plug the motor back in the fuse blows? i'm not getting any voltage at the terminals wear the motor plugs in to the MCB, theres no obvious sign on the MCB of any broken components on the board itself....

    couple of pics...

    http://i.imgur.com/HBTjX.jpg
    http://i.imgur.com/jRnlr.jpg
    http://i.imgur.com/E529C.jpg

    thanks guys
     
  2. trini1

    New Member

    Aug 24, 2012
    6
    0
    Try replacing the rectifer and mosfet the same time an see if it help.
     
  3. PackratKing

    Well-Known Member

    Jul 13, 2008
    850
    215
    I suspect *trini1* is on track, though can you add a picture of the underside of the PCB shown ? I'm amazed that those tiny diodes are the rectifier for a treadmill motor.........:eek:
     
  4. BSomer

    Member

    Dec 28, 2011
    433
    106
    Actually, I think those small diodes are for something else. The rectifier looks to be on the bottom side of the PCB next to the large capacitor and what looks like a NTC/PTC. It is probably about a 15 - 20A bridge rectifier.
     
  5. toki111

    Thread Starter New Member

    Aug 25, 2012
    8
    0
  6. PackratKing

    Well-Known Member

    Jul 13, 2008
    850
    215
    That picture is more like it, and that monolithic bridge is more than likely the culprit. Have you any room for a substantial heatsink in the chassis box ?? 'cuz those puppies can put up some heat.........forced ventilation wouldn't hurt either.....
     
  7. toki111

    Thread Starter New Member

    Aug 25, 2012
    8
    0
    the bridge rectifier sits directly on the chassis box, i could put a small fan in there?
     
  8. toki111

    Thread Starter New Member

    Aug 25, 2012
    8
    0
    thanks guys!! the culprit was the mosfet, unfortunately they had stopped making the one i was after, so had to get a similar one.......but its up an running now :) i'm glad i found this forum, lots of interesting stuff to read an learn :) thankyou again guys
     
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