Avalanche transistor

Discussion in 'The Projects Forum' started by jaysnoe, Mar 10, 2011.

  1. jaysnoe

    Thread Starter New Member

    Mar 10, 2011
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    Hi,
    Im trying to build a Marx generator using Avalanche Transistors as switches. I Need to get pulses of 1kV or More. I have HAve done the schematic on LtSpice as seen on the attached Schematic. However, i need to characterize one of the Avalanche transistors to be the triggering switch rather than the Power MOSFET used.

    I dont know how to do this and i would appreciate it if you could help as this is my last glitch before i can build it on a pcb.
    Thank you in advance
    Regards
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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    What is the application?
     
  3. jaysnoe

    Thread Starter New Member

    Mar 10, 2011
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    Sorry, what do you mean "whats the application"?
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
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    Marx generators are used to produce extremely high voltages. What will your generator be used for?
     
  5. jaysnoe

    Thread Starter New Member

    Mar 10, 2011
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    Oh Ok, sorry. Its a University project and as a cost cutting measure i have been advised I no longer have any extra money to purchase the MOSFET used on the simulation. So i have been told that i can characterize or condition the ZTX415 transistor for a Marx bank. I hope that clarifies everything.
    Thanks
     
  6. beenthere

    Retired Moderator

    Apr 20, 2004
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    Have you got a data sheet on that transistor? It will go 60 amps peak, but only 20 ns pulses.
     
  7. jaysnoe

    Thread Starter New Member

    Mar 10, 2011
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    I have looked at the schematic and im indeed aware of that.
    Ok, hear is the schematic of what im trying to do and a brief explanation of what i need from the circuit.
    I want the transitor to conduct when it reaches breakdown, currently what im getting from the switch is a continous current and the transistor will not conduct which if allowed to continue will infact burn the transistors. I have been informed the shematic here attached will perform this requirement, with the right settings however i seem not to be getting that to happen.
    Please help:confused::confused::confused::confused::confused:
    Thanks
     
  8. jaysnoe

    Thread Starter New Member

    Mar 10, 2011
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    I have finally cracked and i will be posting the results asap. Thank you all for your effort.
     
  9. jaysnoe

    Thread Starter New Member

    Mar 10, 2011
    6
    0
    Hi,
    Here is the circuit simulation i used to test the breakdown. Basically the circuit was the same as the one i attached earlier on.
    for the Circuit transistor to conduct, there has to a minimum of 1A current flowing between the collector and emitter anything lower than that will not make the transistor conduct. The transistor breaks down at 300V conducts to nearly ZERO then recharges again.
     
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