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Dummy load

Discussion in 'Electronic Projects Design/Ideas/Reviews' started by Doctore, Aug 17, 2013.

  1. ronv

    ronv Well-Known Member Most Helpful Member

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    What are you trying to load with 500 amps?
    There may be better ways for that much current.
     
    • Like Like x 1
  2. Doctore

    Doctore Member

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    Im thinking about making universal dummy load, for many kinds of psu, batteries, dc-dc converters etc.
    So there is no specified voltage or current.
    Sup57n20 seems be still best mosfet, I was digging around for better mosfet and I dont find nothing better at good price.
     
  3. Tony Stewart

    Tony Stewart Well-Known Member Most Helpful Member

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    Check out this design http://www.edn.com/design/analog/4368416/Design-a-100A-active-load-to-test-power-supplies


    translated https://translate.google.ca/translate?sl=auto&tl=pl&js=y&prev=_t&hl=en&ie=UTF-8&u=http://www.edn.com/design/analog/4368416/Design-a-100A-active-load-to-test-power-supplies&edit-text=

    Digikey site says....

    Shipping Rates for POLAND
    Order Amount: Under $200.00
    Ship Rate: $60.00
    FREE* $200.00 or more

    UPS World Wide
    FedEx International Priority
    DHL Express International

    All costs listed in USD
     
    Last edited: Oct 27, 2015
  4. dave

    Dave New Member

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  5. Tony Stewart

    Tony Stewart Well-Known Member Most Helpful Member

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    my best choice

    XFH340N075T2-ND
    Price Break Unit Price Extended Price
    1 8.45000 8.45
    10 7.60500 76.05
    100 6.25300 625.30
    250 5.74600 1,436.50
    500 5.23900 2,619.50
    1,000 4.56300 4,563.00
    2,500 4.39400 10,985.00
    5,000 4.22500 21,125.00
    10,000 4.15740 41,574.00
    Quantity Available Digi-Key Stock: 90
    Can ship immediately

    [​IMG] 1 [​IMG] IXFH340N075T2-ND MOSFET N-CH 75V 340A TO-247 5 1kW max.
    Immediate 0
    $8.45000 x5= $42.25

    Use semi-rigid copper plumbing pipe for connections. ie. LOW INDUCTANCE. Hollow better for skin effect for low R and low cost.
     
  6. Doctore

    Doctore Member

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    Thanks Tony, I will look at this project.
    But I dont think that I will use that mosfets because they are almost 4 times more expensive than sup57n20 and sups have 50W more Pd.
    They are also 75V, I would like to run up to 100V and have some spare for errors, like that faulty 2kW SMPS with above 200V spikes, because crowabar circuit need few ms to run, and then fuse also need few ms to burn.
    I also can get that sup57n20 for free(samples).
    And because mosfets will be soldered it can be problematic to replace them, so I would like to protect them by any possible way.

    What about fuse on each mosfet?
    But then we also need some control, to detect burned fuse and turn off all other mosfets to prevent "chain reaction" ;p

    But anyway, I want to bulid DIY lab PSU first, because at this time psu is more important/needed.
     

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