PC power supply as bench power supply

Discussion in 'General Electronics Chat' started by xxxyyyba, Nov 19, 2015.

  1. xxxyyyba

    Thread Starter Member

    Aug 7, 2012
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    What do you think about converting pc power supply to bench power supply?
    Is it ok for amateur use?
     
  2. dl324

    Distinguished Member

    Mar 30, 2015
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  3. MrSoftware

    Active Member

    Oct 29, 2013
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  4. xxxyyyba

    Thread Starter Member

    Aug 7, 2012
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    Does PC power supply contains short circuit protection?
     
  5. wayneh

    Expert

    Sep 9, 2010
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    Yes, usually.
     
  6. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    Most PC supplies have enough power to run most home hobby electronic stuff. But the current limits are set way too high to protect most things. If you are firing up a preamp circuit or an Arduino thingy with a wiring problem, having a supply with the current limit at 20 amps is not going to protect your circuit. Also, neither the voltage nor the current limit levels are very adjustable, if at all. Finally, the output noise usually is at the max possible limit for what a computer can handle, and can cause problems for just about anything else. There is a lot of cheap, regulated power, but it has some serious baggage.

    ak
     
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  7. Dodgydave

    Distinguished Member

    Jun 22, 2012
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    I have made several of these Atx psus variable by modifying the pwm feedback, giving a voltage range of 1.9 to 28V @22 amps...its a matter of finding which chip is used in the atx.

    http://danyk.cz/s_atx_en.html
     
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  8. AnalogKid

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    Aug 1, 2013
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    True, but given the OP's self-description and the general content of his other posts, my guess is that such surgery is beyond his skill set.

    ak
     
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  9. Hypatia's Protege

    Distinguished Member

    Mar 1, 2015
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    Be advised also that stable, reasonably low noise, operation of PC PSUs requires a minimum load...

    Best regards
    HP
     
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  10. AnalogKid

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    Darn those 99 cent magnetics...
     
  11. wayneh

    Expert

    Sep 9, 2010
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    A great first project is to build yourself a LM317-based power supply with the input coming from an old PSU. The LM317 gets rid of the noise from the PSU and can handle plenty of juice for lab bench projects. And it will shut itself down if your project shorts.
     
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  12. Hypatia's Protege

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    Ok, I give up -- To what does "99 cent magnetics" refer?:)
     
  13. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    Minimum load requirements caused by undersized, low quality, ultra-low cost magnetics. OK, that and no internal minimum load resistor.

    ak
     
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