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Author Topic: Has anyone used a computer power supply for their rig?  (Read 1861 times)
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W4EWH
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« on: October 03, 2020, 10:10:50 PM »

I'm curious: have you used a PC computer power supply as a 12 volt source for a transceiver? I don't know how much current the 12v sections of PC supplies can source, but if they'll supply ~15 amps, they could run a lot of rigs.

Thanks for thinking about it.

Bill, W4EWH
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Pete, WA2CWA
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« Reply #1 on: October 04, 2020, 12:11:55 AM »

A lot depends on what the manufacturer puts into the computer as default. A lot of the older PC's used 200 to 300 watt power supplies. Some of the more recent PC's run 400 or 500 (or more) watt power supplies. A  lot of the newer video cards really suck up the current. It's not unusual on some of the newer PC power supplies where the +12 volt rail is rated at 25 or 30 amps.

I recall using an old PC power supply (I think it was from a 386 machine) to run a 12 volt 2m transceiver on the bench for some testing. I don't recall having any problems doing that but it was in the last century.
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WU2D
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CW is just a narrower version of AM


« Reply #2 on: October 04, 2020, 06:48:14 AM »

Takes about 2 hours max to do one. Add Bypassing and Ferrites! EMI can be an issue.

I converted a couple of them and can report that they both were capable of handling a small 100W solid state rig I have. But at only 12 VDC out, they are not as good as a fully charged battery with a trickle charger!

To fool the supply into activation, you have to connect a load resistor between ground (black wire) and +5 V (red wire). The minimum current is about 1 Amps (actually lower to activate my units, I think I used a 150 Ohm sand resistor). An ATX power supply has a green wire for power up. Connect the small green wire with any black wire. All black wires are connected to ground. I just tied ALL of the yellow wires together and half of the black wires and brought them out to big Standoffs.

Getting them up to 14 VDC can range from simple to impossible depending on the manufacturer, because they have an overvoltage shutdown feature. Some you can turn up a bit.

Be sure to connect the chassis together with a ground wire independent of the Black Power wire. Beads both on AC Cord and the Power Feed. And plenty of bypass caps across the power terminals inside and outside.

73's Mike

 


* ATX_Supply.JPG (181.2 KB, 1266x806 - viewed 296 times.)
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WD5JKO
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WD5JKO


« Reply #3 on: October 04, 2020, 01:25:52 PM »



Here is a 40m 550W AM Class E rig built into 4 computer power supply cases:


http://www.lu8jb.com/Transm_550w_2SK1520.htm

The cases can be used for a variety of projects.

Jim
Wd5JKO
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