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rectifier problem

Discussion in 'General Electronics Chat' started by milosz125, Mar 25, 2013.

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  1. milosz125

    Thread Starter New Member

    Apr 6, 2012
    Hello All

    I have problem with electric drive project.

    The drive consist of 220V DC motor (classic with brushes ) and control circuit which controls the motor. Motor is controlled in left/right style via two contactors.

    The available power supply is 230 V AC 50 Hz (European type) 1 phase - TN-C type (L and PEN wires).

    To supply the motor, a bridge rectifier is used. However without seperation transformer; drawing is attached to post.

    My question is , is it done correctly to supply that motor in that configuration ?

    What type of system is that part behind bridge?
    I think grounding should be done carefully because if negative (-) wire of DC side will be grounded, it causes (when AC current starts to flow in negative period) high faulty current flow from source, through earthing, (-) wire, diode D1 and to source (V1).

    So in DC side connection between negative wire and PE wire is not allowed.

    Anyway designer of that circuit claims that everything is correctly designed.

    Are there any regulations concerning AC/DC system interaction?

    Please help.


  2. BillB3857

    AAC Fanatic!

    Feb 28, 2009
    Look at your circuit. Does it make any sense at all to have ground at both ends of the lower right diode? Likewise, you are right about high currents through D1 on the negative transitions of the AC line. Remove the ground from the motor lead.
  3. Wendy


    Mar 24, 2008
    This is very close to being a transformerless power supply, which is against our Terms of Service. I am going to close this thread due to this.
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