Very High Voltage Audio Amplifier

Discussion in 'The Projects Forum' started by tedh_PA, Jun 26, 2008.

  1. tedh_PA

    Thread Starter New Member

    Jun 26, 2008
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    I've read about high power audio amplifiers running with a supply rail of a couple hundred volts, but can an amplifier be designed to run with a supply of over 2000V and achieve an output swing as near as possible to that rail?
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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    Almost certainly, but what would handle the output? Why would you be concerned about swinging to 1995 volts as opposed to 1999 volts? Is this about a mega audio amp, or for some other application?
     
  3. mik3

    Senior Member

    Feb 4, 2008
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    You have to use special design transistors which can handle this high voltage which are expensive. Also, they must be able to switch the voltage from 0 to almost 2000 Volts in less than 12.5 us .

    Why do you need this kind of amplifier?
     
  4. Audioguru

    New Member

    Dec 20, 2007
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    There is an article on the web where a guy made a very high power audio amplifier from radio station transmitter huge vacuum tubes.

    The MTX Jackhammer 22" sub-woofer is rated at 6000W RMS. It needs 4 strong guys to lift it. There is a funny video on the web where some guys installed one in a car. The windows and the guys' ears didn't last very long.
     
  5. tedh_PA

    Thread Starter New Member

    Jun 26, 2008
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    This circuit is not for a standard audio application. The input signal is band-limited <1 kHz and is pulsed (or gated) so average power is low although instantaneous power will be high. Pulses are about 1/2 second duration and duty cycle is about 1%. It needs to be quite small (< 12 sq. in.) and weigh less than 1 lb. The circuit will drive a rather large step-up transformer.
     
  6. tedh_PA

    Thread Starter New Member

    Jun 26, 2008
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    Being band-limited to 1kHz sinusoidal, a 2000 Vpp signal requires a slew rate of about Pi V/uS.
     
  7. JoeJester

    AAC Fanatic!

    Apr 26, 2005
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    I'm sure these water cooled tubes would fit the bill and give you lots of kW output.

    Just to let you know, the filaments were 12V at 275 Amperes. Being you would need a class B or AB1 or AB2 operation, that's two tubes.

    I can provide the specs for these ITT tubes ...

    p.s. Let me know if you intend to use these tubes. I'd want to buy stock in your electric company. :D
     
    Last edited: Jun 26, 2008
  8. beenthere

    Retired Moderator

    Apr 20, 2004
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    Possibly, Ebay might still have one of those old Electro-Voice speakers with the response rated from DC to blue light. Too bad it takes 3 train cars to haul one.
     
  9. Externet

    AAC Fanatic!

    Nov 29, 2005
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  10. tedh_PA

    Thread Starter New Member

    Jun 26, 2008
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    Oops... mistyped. I meant 2*Pi V/uS.

    Tubes are not an option here. Must be solid state. I'm wondering if there are BJTs that can handle this voltage. I know there are a few MOSFETs that come close. Is there a way to 'stack' transistors to spread the voltage drops evenly across multiple devices?

    This project is 'audio' in frequency only. I'm not driving a speaker. Distortion and linearity are less critical here than in normal audio.

    Thank you for the interesting comments.
     
  11. beenthere

    Retired Moderator

    Apr 20, 2004
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    A flip through the catalogs shows nothing in the line of FET's of IGBT's with Vce ratings above 1200 volts.

    If your interest is in controlling power to a load, can you rework things for a lower voltage and more current? What is the nature of the application?
     
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