140 volt zener

Discussion in 'General Electronics Chat' started by aac9876, Jun 3, 2014.

  1. aac9876

    Thread Starter Active Member

    Dec 9, 2006
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    Some voltage clippers that are designed to protect wind turbines use a combination of resistors and zeners to do it.If you look at most Zeners they can have high voltage but most seem to have very low current limits...
    Can you buy a 140 volt Zener that has a high amp/watt rating too
    like 1000 watts that will stand up to the power coming out of a wind generator??
     
  2. Papabravo

    Expert

    Feb 24, 2006
    10,135
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    Why do you think a zener has to dissipate that much power?
    Can you show us a schematic?
     
  3. crutschow

    Expert

    Mar 14, 2008
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    No, a zener can't dissipate that amount of power by itself. To dissipate that power you could use a zener to turn on some power transistors connected to a large heat sink or to switch on some large power resistors (room heaters).
     
  4. #12

    Expert

    Nov 30, 2010
    16,248
    6,745
    You're missing some basics here. How much power?
    Do you want this pseudo-zener to dump 10 amps? 100 amps? a thousand amps?
    Wouldn't it be better to use the regulator on the turbine to reduce its power conversion rate? Kind of, "un-harness" it?
     
  5. aac9876

    Thread Starter Active Member

    Dec 9, 2006
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    so you think it would be good to use a zener to switch on a resistor of some kind to slow it down..
    would that be sufficient to protect the charge controller against an instantaneous voltage
    spike,150v, of some kind...
    ??
     
  6. inwo

    Well-Known Member

    Nov 7, 2013
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    Selenium are available up to 200 amps at least.
     
  7. ronv

    AAC Fanatic!

    Nov 12, 2008
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    I think those are called load dump controllers. Usually something like a zener turns on a transistor and the current is "dumped" into something like a resistor bank or electric water heater. The mechanical design usually turns them away from the wind at a certain speed as well.
     
  8. #12

    Expert

    Nov 30, 2010
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    Do you mean something like this?
     
    Last edited: Jun 4, 2014
  9. alfacliff

    Well-Known Member

    Dec 13, 2013
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    considering theinertia of the blades and generator, a high sppeed voltage spike from a wind generator is unlikely. and to protect against too high output, just size the blades so the load on the generator can hold the speed down to safe speeds, then the dump load will not be used very much.
     
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