Pulsemotor control

Discussion in 'The Projects Forum' started by MR2, Jan 15, 2007.

  1. MR2

    Thread Starter New Member

    Dec 25, 2006
    4
    0
    Hello

    I would be glad for help building a pulsecontroller to my new motor.
    I have tried with relays, solid state relays, igbt's and transistors.
    My knowledge to electronics is very bad, and all that has happened is blown fuses (16Amp), burned relays, and exploded transistors. Or nothing happens...

    I have attached a pic that show the essential of the circuit.
    The relays are triggered from a PLS, that has 24V DC output signals.
    The input signal from motor to PLS is via a inductive sensor. That part is all OK.
    The problem is giving the capacitor its charge, and then pulse the charge to the electromagnet. The measured resistance of the electromagnet is 5.1 ohm.

    At this moment I am using only 230V AC from wall outlet, but are planning to use 1500V DC and 3000V DC at a later stage.

    I have bought 2 IGBT's, irg4pc40s ( http://download.siliconexpert.com/pdfs/transistor/inr/irg4pc40s.pdf
    ) that I think should be enough at this moment. Pulsed amps is 120 @ 600V.

    I have read that IGBT's are "new version" of spark gaps.

    Is there anybody that can help me with a complete circuit with these IGBT's?
     
  2. MR2

    Thread Starter New Member

    Dec 25, 2006
    4
    0
    This is the circuit that I have tested.

    Mecanical relays is too slow, and produces sparks, and burns.
    K1 and K2 is pulsed by PLS.
     
  3. mrmeval

    Distinguished Member

    Jun 30, 2006
    833
    2
    What are you trying to do that needs this form of control? What is the motors specifications? I don't know your level of knowledge but it sounds like you should go buy a compatible controller.
     
  4. MR2

    Thread Starter New Member

    Dec 25, 2006
    4
    0
    All timings and so is ok.. it is only the "power circuit" I need. That can handle the large currents from the capacitor.

    According to the formula of charge/discharge of capacitors i have 5ms dischargetime to release 55.4 Joules to 5 ohms. That is 66 Amps / 22000 watts at the switchingpoint.

    Earlier this problem has been solved with spark gaps/brushes, but I want to switch my capacitors with electronics.
     
  5. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    The IGBT you've chosen can't handle the current unless your pulse rate is less than about 300Hz.
     
  6. MR2

    Thread Starter New Member

    Dec 25, 2006
    4
    0
    The pulses now is about 5 ms.. that will be 200 hz.. Then I have theoretical 1653 RPM's on my motor. I need 1500, so that is in range.
     
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