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30kv .3mA DC power supply tips?

  1. Nov 11, 2011 #1
    Hello, I interesting in making a high voltage power supply for capillary electrophoresis. Not much power is required and the DC does not need totally noise free so I figure this gives me a lot of flexibility. I would love the ability to adjust the voltage at 5kv increments in maybe a 5-30kv range. It would be great if the voltage could be adjusted/turned on+off using a microcontroller whether I need analog output or to add a relay/transistor it doesnt matter. Also I would prefer to power this supply using either 5 or 12V DC.

    Can anyone point me in the right direction? I bet there are some exotic circuits that this would be perfect for.

    I am looking for something that uses less then 20$ worth of parts, or a commercially available unit for around that price.

    Any help would be great.
     
  2. jcsd
  3. Nov 11, 2011 #2
    I have been looking into a Cockcroft–Walton circuit for this. Apparently it can be run with either AC or pulsed DC.

    Running on of these on 12V DC would be a huge pain, around 1000 stages are needed.

    Does anyone know of a very low cost high voltage AC generator that runs off 12V that is commercially available?
     
  4. Nov 12, 2011 #3
    If you had around $200.00 availiable then maybe you could purchase a ready built supply or the parts to build one.
    You could check on ebay and you might find a power supply for $20.00.
     
  5. Nov 14, 2011 #4
    I would suggest using an inverter. You can use your house socket (120 VAC), a transformer (probably a step-up or some other high voltage transformer), some transistors, and switches.

    **Safety Warning**
    Very high voltage!! It can kill you!!

    Using that stuff would be a hack job though for $20 or less. The specifics that you request (5KV increment) requires custom design which is going to cost more whether you do it yourself or you find a commerical product. Your SAFEST bet is go buy it commerically because then it will most likely be UL listed.
     
  6. Nov 14, 2011 #5

    cmb

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    This is TV line output flyback territory. You can usually pick one up for a couple of bucks, then build a switching circuit.

    There are diy-level instructions at http://www.blazelabs.com/e-exp03.asp , where they are suggesting getting 2.2mA at 30kV from one.

    If you can wait 8 months, then [if anyone is interested] I'll pin up here a patent of mine that is currently filed but not published that can also accomplish your requirement with much less effort. (I have a 1 to 20kV 5mA prototype I've been using for HV work for the last year, which I built from new commercial stock parts for a total BOM = 12 euros, and which you can stack in parallel or serial with the same again as it is a DC uncoupled output.)
     
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