PSU to run a CB Radio

A co-worker has a 12v automotive CB radio he wishes to use in the house.
With it's amplifier he will need around 150w. Dedicated AC to DC converters are enormously expensive.

I see no reason he could not use a computer PSU to do the job. Jump the green to black wire, hook up a fan to ensure load on the PSU, connect red to red, black to black plus a ground wire from the case of the radio to the PSU, and it should work.

I am grateful for any thoughts you have on this. Thanks!
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  1. Best answer
  2. Interesting. I had not thought of that - nor had he I am sure. :) Thanks rolli59!

    Still, I am hoping for a positive response that my above idea is practical.
  3. If you draw power from the 4-pin Molex output connector of a PSU, here is the color coding:

    Note that Ground is Black, Yellow is +12 VDC, and Red is +5 VDC - not needed by your app (unless a small load is needed on the +5 VDC line to operate in this non-standard configuration).

    A Molex 4-pin often is not wired very heavily - after all, its intended use is for HDD's etc. that use less than 1 amp each. Your friend's system will need more like 13 to 15 amps available. But if you go to the 20-pin output that is supposed to plug into a mobo, the pinout diagram is here:

    Again, Black is Ground, Yellow is +12 VDC., and it is designed for higher currents.

    In buying a PSU, remember that not all its output Watts are on the +12 VDC line. For example, I checked a cheap ($25) 180W PSU and its +12VDC line can output only 10A - net enough for your friend's 150W application. Some cheap 250W units with SINGLE 12 VDC rails put out 13A to 16A max, depending on the unit, just barely enough. A DUAL-rail +12VDC PSU probably is NOT what you want because its +12VDC ouput is split, and you may not get enough from one rail to meet your 13 to 15 A requirement.
  4. I bookmarked this page and will ask my friend for exact numbers and get back.
    [:henry chinaski:8] I have never looked at pinouts. Dummy me!!
    Glad you mentioned it.
    I would have made a mistake.
  5. Talked to my coworker today, his wife made the final decision....! :)

    She seems to feel the converter recommended by rolli59 would pose less of a fire hazard (?) to the family.
    "When mama ain't happy, ain't no one gonna be happy"

    Thanks guys!
  6. Best answer selected by Noworldorder.
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