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ZENER BREAKDOWN has caused me a breakdown

  1. Nov 20, 2009 #1
    could any1 plz explain avalance effect
    i can understand that the electrons minority carriers are accelerated by high voltage and collide with valence electrons break free them and what happens after that
    do they all go back to the positive terminal plz explain after the production of avalanche of electrons
     
  2. jcsd
  3. Nov 22, 2009 #2
    The newly liberated electrons, provided they have enough energy, do the same to other stationary electrons.

    Hence the term avalanche.
     
  4. Nov 23, 2009 #3
    after that what will happen thats what my question
     
  5. Nov 24, 2009 #4
    you'll observe high amounts of current at the external circuit.
     
  6. Nov 25, 2009 #5
    ok high amount of current will flow from the n type to the + terminal
    but then who will fill the holes caused now in the n type due to collision by the minority carriers on the valence band electrons of n type
    those places will be vacant and there will be holes in n type what will happen next????
     
  7. Nov 25, 2009 #6
    Unsure from your wording exactly what's bothering you, you seem to be questioning both the avalanche effect itself and then what happens after that when the Zener diode is switched on....but free electrons drift in a circuit with a zener diode just like any another other circuit, filling holes .

    Try: http://en.wikipedia.org/wiki/Electrical_current for a general discussion

    Also try here, it seems applicable to your concerns:
    http://en.wikipedia.org/wiki/Zener_diode
     
  8. Nov 25, 2009 #7
    ok i 'll come straight to the point now
    plz explain the flow of electrons through the entire circuit till it completes one cycle in
    1) avalanche breakdown
    2) zener breakdown
     
  9. Nov 25, 2009 #8
    I don't know where you are going with this.

    There are far too many electrons around, to fill those "vacancies" in extremely fast timescales.

    Is there any experimental or theoretical motivation behind all this?

    Or are you just feeding your curiosity?

    There are effects like "source starvation" observed in small devices where the source cannot supply enough electrons to the circuit, and all that is seen by a decrease in current.

    But such a thing will NEVER happen in a Avalanche breakdown mechanism, because you are NOT budging the CORE electrons at ALL ! Ripping a few outer shell electrons and seeing a large current is all you see. Before you can rip the core electrons, you'd need much greater voltages and by that time you'd have burned up your whole circuit anyway...
     
  10. Nov 25, 2009 #9
    ok then explain zener diode and zener breakdown
    how there it does not happen what happens in avalanche breakdown
    in both the same will happen
    but in zener diode what special will happen which does not happen in avalanche breakdown
     
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