Current limiting to 5A at 240V

Discussion in 'General Electronics Chat' started by Atton, Aug 30, 2015.

  1. Atton

    Thread Starter New Member

    Aug 30, 2015
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    So I have an inverter that is capable of producing about 3000 watts. I am wondering how I could keep this inverter at 1200 watts or 5A, I know this can be done with an inductive ballast however I am not certain how this should be done. Above all I would like to avoid turning the inverter into a burning mush.
     
  2. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    What happens when you connect a 2W lamp to a 12V starting battery that is capable of 2000W?
     
  3. Atton

    Thread Starter New Member

    Aug 30, 2015
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    The resistance of said lamp limits the current to what said lamp is specified. That is something I have come to understand pretty well. However I must ask how can this be done with a transformer in order to limit current in safe fashion.
    I mean I've tried making some on Yenka that can do it.
     
  4. tcmtech

    Well-Known Member

    Nov 4, 2013
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    You could just put a fast acting 5 amp fuse or circuit breaker in line with the output. :rolleyes:
     
  5. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    Current draw from the transformer takes care of itself due to the effective resistance of the device you are connecting. Wire between the transformer and your device is sized for the expected current.

    Fusing is done to protect against a fire in the event that a short-circuit due to a breakdown in insulation, or other critical failure in your device that causes huge currents (several times the expected current) to flow in wire (circuits) not designed to carry that much current. Fusing is always placed between the source (your transformer), and the wires feeding your device.
     
  6. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    Why? Given that the inverter output current is set by the load characteristics, are you trying to limit the current to one load so that the rest of the current is guaranteed available to some other load? And note that current limiter circuits work by reducing the output voltage when the current demand exceeds the set point. This can be done with a brick wall device like a circuit breaker, or a variable impedance device like a constant current circuit, but one way or another, when the current exceeds 5 A the voltage is gonna drop. Can the 5 A load handle that?

    ak
     
  7. Atton

    Thread Starter New Member

    Aug 30, 2015
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    The reason is pretty simple and I should have given more detail. But I was thinking of attaching a step down mot to the inverter for giggles and so on. The inverter can only run about 1.5kw constantly so I want to be sure that I can prevent it from going over that.
     
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