Need help!

Discussion in 'General Electronics Chat' started by xxredxpandaxx, Mar 28, 2011.

  1. xxredxpandaxx

    Thread Starter New Member

    Mar 28, 2011
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    I have a power source that is 680V DC and 5mA and I wanted to change it to 24mA. I wanted to know how to do this. thanks for any help.
     
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Hello redxpanda,
    Welcome to AAC.
    We generally like for our new posters to stay with low voltages. 680VDC is a dangerous voltage level. It doesn't take much current to kill a person at that voltage.

    What are you doing with this power source?

    What is the power source itself? Did you build it? Do you have a schematic of it?
     
  3. xxredxpandaxx

    Thread Starter New Member

    Mar 28, 2011
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    Thanks for the warning, I know that it doesn't take much to kill a person at high voltages. The power source is a driver for cold cathodes, and I wanted to replace it with leds instead of the cathodes, thats why I need the 20-24mA. I did not build it and I don't have a schematic of it sorry.
     
  4. SgtWookie

    Expert

    Jul 17, 2007
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    Well, instead of trying for 680VDC @ 20mA, why not run a bunch of series strings in parallel at a much lower voltage? It would be a lot more safe.
     
  5. xxredxpandaxx

    Thread Starter New Member

    Mar 28, 2011
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    Well I already have this power source and it is sound reactive and I don't want to go through the trouble to make one the same but with lower volts and higher amps. I just want to get more mA out of this power source.
     
  6. SgtWookie

    Expert

    Jul 17, 2007
    22,182
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    That would require a complete re-engineering of the existing supply, as the components would not be rated for 3x-4x the design current at that voltage.

    Just about everything would have to be replaced.
     
  7. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
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    Does the sound source supply power to the CFL inverter? If so, you may be able to simply remove the inverter and, by use of some current limiting resistors for your LEDs, use the sound source directly.
     
  8. xxredxpandaxx

    Thread Starter New Member

    Mar 28, 2011
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    could I build another component that would hook up to the out put of the power supply that I already have to give me 20-24mA?
     
  9. BillB3857

    Senior Member

    Feb 28, 2009
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    How much current does the CFL inverter draw? You may be able to simply substitute LEDs (with proper limit resistors) for the inverter.
     
  10. xxredxpandaxx

    Thread Starter New Member

    Mar 28, 2011
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    it draws 700mA at 12v dc
     
  11. BillB3857

    Senior Member

    Feb 28, 2009
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    IF, and again this is a big IF, the CFL inverter is being driven by the audio signal, you should be able to to use what is now the input to the CFL inverter to drive your LEDs. Do you have a scope? Can you verify that the input to the inverter is indeed audio or audio riding on top of a DC level?
     
  12. xxredxpandaxx

    Thread Starter New Member

    Mar 28, 2011
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    I am not really sure on all that stuff really. but I decided instead to try to build a large scale one of these.
     
  13. BillB3857

    Senior Member

    Feb 28, 2009
    2,400
    348
    Looks like a great project for you. Good luck with it. Let us know how it turns out.
     
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