Creating an oscillating waveform

Discussion in 'The Projects Forum' started by Cincy10, Feb 5, 2008.

  1. Cincy10

    Thread Starter New Member

    Feb 5, 2008
    2
    0
    I need to create an electrical signal that resembles the shape of a heartbeat pattern. I need it to carry 50-100W. I want to operate at 0V baseline. At t=0, I need a +5000V spike, immediately dropping it back to 0V, followed immediately by a -5000V spike, immediately returning to 0V. I want capability to repeat this cycle, varying the rest period between voltage spike pairs to generate an adjustable frequency between 40KHz and 1.5MHz.

    I originally thought I would start with a +/- 12V signal and boost it to 5000V; I picked 12V because I planned on using an automotive coil to transform voltages from 12 to 5000V. However, since coils operate today in the magnitude of 25kV output, perhaps I could use a smaller input voltage to get the Vout in the 5000V range. I seem to recall the DACs I formerly used output 1-5V.

    (I have a little experience with Process Control. It seems doable for me to use a computer and a lookup table, or subroutine to create an output waveform. It's been 20 years since I've done this sort of thing, and I can't remember exactly how to accomplish this)

    Can anyone give me input on how to generate this waveform?

    Can anyone direct me to a resource or tutorial that might be a good refresher for me?
     
  2. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    As a refresher tutorial, the eBook here at AAC is a spiffy resource. Links are at the bottom of this page.

    I don't know of any DAC able to output 50-100W. You'll need a push-pull current amplifier between the DAC and your coil.
     
  3. Ron H

    AAC Fanatic!

    Apr 14, 2005
    7,050
    657
    How wide (in time) do you want these spikes to be?
     
  4. Cincy10

    Thread Starter New Member

    Feb 5, 2008
    2
    0
    50 nanoseconds
     
  5. Ron H

    AAC Fanatic!

    Apr 14, 2005
    7,050
    657
    If you only had a 10pF load, you would need 5000V at 1Amp to slew 5000V in 50nS. If you want to go up in 25nS and back down in the other 25nS, it will require 2A, in each direction.
     
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