Using two or more relays for large currents.

Discussion in 'The Projects Forum' started by stoichiometry, Jan 14, 2011.

  1. stoichiometry

    Thread Starter New Member

    Jan 14, 2011
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    Hello,

    I am working on a windturbine for an off-grid application. I have a circuit diagram for a small charge controller that functions well with small 12 Volt relays. The problem (well, not really problem :D) is that I've created a turbine that produces some large current ... I am not interested (yet) in making a new stator for higher voltage/lower current.

    So, my question ... is there a way to split the incoming 12 Volt DC current (160 amp max @ high wind speeds) over two or more automotive style relays?

    Kindly,
    Matt
     
  2. GetDeviceInfo

    Senior Member

    Jun 7, 2009
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    if you could limit your current to the value of an individual relay, switch the relay, increase one more step, switch the next relay, etc., that may work. Trying to pull multiple relays in to service the total current would likely end up in an explosion of contacts.

    I'm sure you could find an old motor starter contact capable of your current, kicking around somewhere.
     
  3. CDRIVE

    Senior Member

    Jul 1, 2008
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  4. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    Loads will automatically "split" based on the amount of resistance they have (current they draw).

    If you put 2 12V 10W light bulbs on the output, they would both draw the same current. Current isn't going to be forced through the bulbs unless the voltage increases.
     
  5. stoichiometry

    Thread Starter New Member

    Jan 14, 2011
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    Sorry about that ... I thought I was editing my title to a more appropriate title, and must have used the browsers 'back' button and reposted.
     
  6. CDRIVE

    Senior Member

    Jul 1, 2008
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  7. SgtWookie

    Expert

    Jul 17, 2007
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    You might just use a Ford automotive starter solenoid (relay). Not sure how well the coil will stand up under continuous use, but you could use a solenoid driver circuit to reduce the current flow through the coil once the relay engages.
     
  8. soda

    Active Member

    Dec 7, 2008
    174
    13
    Hi

    What you need to switch those type of amperages is a contacter-relay wich is a heavy duty relay. Don't even think of using a normal low voltage relay because it will burn up instantly.

    When we use electronics with our high voltages, we usually use stud triacs which then drive the contacter- relays.

    The one i show you is only a small 230vac type and can switch currents up to 20A

    I think, to be able to buy one you need to show a high voltage(50kv) license.
     
  9. stoichiometry

    Thread Starter New Member

    Jan 14, 2011
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    CDrive,

    I am making the following -- save for I want to replace (or use more than one relay for ca 160 amps input).

    [​IMG]
     
  10. GetDeviceInfo

    Senior Member

    Jun 7, 2009
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    why are you not regulating the alternators field? Switching load current can be done as a safety, but not as regulation.
     
  11. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    I have the same question, especially when dumping the load simply to create heat.

    If the dump load is active a lot, you may want to get a bigger inverter and run more stuff from wind power, or do a grid-tied system.
     
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