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Large Voltage Amplification for arbitrary signal generator — Parallax Forums

Large Voltage Amplification for arbitrary signal generator

ArchiverArchiver Posts: 46,084
edited 2003-01-23 06:57 in General Discussion
I'm in the process of using my Basic Stamp to build an arbitrary signal
generator. I'm going to use it to simulate signals that would be found in a
car. (I'm building automotive test equipment). I've gotten my BS to control
RAM and a DAC through a small CPLD. So I can generate very nice arbitrary
waveforms with the DAC at many frequencies, but my output voltage is limited
to +-5V.

My question to all you super-smart electronics people (I'm just a software
person myself) is this: how can I amplify those +-5V signals to get to
+-100V? The current requirements for the amplifier are very, very, very
small. (Like < 1ma would work just fine - It's only driving a 10MOhm input)

In fact, I couldn't even find equipment that I could buy that would do this!
Are the 'voltage amplifier' modules that anybody sells? It does not have to
be very precise (+-1% of output is more than enough) but it does have to be
fairly fast (I need to be able to reproduce signals that go from 0V to 100V
in about 10us).

Any ideas? Any circuits out there that I can use for ideas?

*Brian

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-01-23 02:11
    I am not sure if they will work in your case, but there are diode voltage
    multiplier networks that are used in television flyback high voltage
    circuits. These can generate upwards of 40,000 volts. But, I would think
    you could use a similar type of circuit for your application, they do not
    offer a lot of current but that seems to be OK for your application. You
    might want to give the NTE site a look and see if they have any on there. <A
    HREF="http://www.nteinc.com/">
    NTE Electronics, Inc. Web Site, Welcome</A>

    I hope this will help.

    Regards,

    Randy Abernathy
    4626 Old Stilesboro Road
    Acworth, GA 30101
    Phone / Fax: 770-974-5295
    E-mail: cnc002@a...
    We service, install and repair industrial woodworking machinery
    Specializing in SCM / SCMI CNC Panel Saws and Routers


    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-23 02:55
    Brian,

    You could use a backlight inverter for your high voltage source. I
    believe they output a couple hundred volts at 400Hz frequency. Some
    filtering and regulation with a HV Zener and you could easily
    generate your high voltage.

    For high voltage switches and mux's go to www.supertex.com

    http://www.supertex.com/products/selector_guides/100

    Some pretty cool stuff there. 200V, 2A, 8 channel analog mux
    controlled with 5V logic. They have a micro BGA package if board
    space is a consideration. I have interfaced one of these with a
    stamp. Code similar to driving a 74HC595. Totally cool.

    Jason


    --- In basicstamps@yahoogroups.com, Brian Schmalz <brian.s@l...>
    wrote:
    > I'm in the process of using my Basic Stamp to build an arbitrary
    signal
    > generator. I'm going to use it to simulate signals that would be
    found in a
    > car. (I'm building automotive test equipment). I've gotten my BS to
    control
    > RAM and a DAC through a small CPLD. So I can generate very nice
    arbitrary
    > waveforms with the DAC at many frequencies, but my output voltage
    is limited
    > to +-5V.
    >
    > My question to all you super-smart electronics people (I'm just a
    software
    > person myself) is this: how can I amplify those +-5V signals to get
    to
    > +-100V? The current requirements for the amplifier are very, very,
    very
    > small. (Like < 1ma would work just fine - It's only driving a
    10MOhm input)
    >
    > In fact, I couldn't even find equipment that I could buy that would
    do this!
    > Are the 'voltage amplifier' modules that anybody sells? It does not
    have to
    > be very precise (+-1% of output is more than enough) but it does
    have to be
    > fairly fast (I need to be able to reproduce signals that go from 0V
    to 100V
    > in about 10us).
    >
    > Any ideas? Any circuits out there that I can use for ideas?
    >
    > *Brian
  • ArchiverArchiver Posts: 46,084
    edited 2003-01-23 06:57
    >how can I amplify those +-5V signals to get to
    >+-100V? The current requirements for the amplifier are very, very, very
    >small. (Like < 1ma would work just fine - It's only driving a 10MOhm input)
    >
    >In fact, I couldn't even find equipment that I could buy that would do this!
    >Are the 'voltage amplifier' modules that anybody sells? It does not have to
    >be very precise (+-1% of output is more than enough) but it does have to be
    >fairly fast (I need to be able to reproduce signals that go from 0V to 100V
    >in about 10us).
    >
    >Any ideas? Any circuits out there that I can use for ideas?


    Hi Brian,

    There's a clever, relatively cheap circuit in "Art of Electronics",
    in connection with linear drive to a piezo actuator (rubber mirror
    for a telescope.) It uses a couple of 1 kilovolt, 3 amp mosfets in a
    feedback loop with a generic op amp. Gain of 100 volts per volt.

    Or, there are high voltage op amps available. The Burr-Brown (now
    Texas Instruments) 3584 will provide about 15 milliamps at +/- 150
    volts and 50mhz GBW. But they cost around $100 each.

    -- Tracy
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