Using a computer power supply?

thereverend2u2 · #1 (**permalink**) 12-23-2012, 11:32 AM

I was wondering if it is at all possible to use 1 COMPUTER POWER SUPPLY. to power my 5 12 volt units that i want to build a box for so i can have them all stacked in one nice looking rack. Has anyone done this and how is it done? How do i switch the power supply on and off etc?? Diagrams welcome..

MERRY CHRISTMAS TO ALL!

rfradioconsult · #2 (**permalink**) 12-23-2012, 4:19 PM

In the world of computers 12Volts means 12Volts, in the world of radios 12Volts actually means the radio is expecting to see around 13.8 Volts at the rated current draw of the device. If you are planning on running a transceiver from your power supply you may run into problems with the most common lower than expected transmit power output. In addition computer power supplies can generate unwanted noise and hash that can interfere with your radio, much better to go with a good commercial power supply large enough to power all your radios at the same time.

thereverend2u2 · #3 (**permalink**) 12-23-2012, 5:56 PM

Do you feel that hte Astron RS-20A unit would power 5 two way radios. The 5 radios would not be transmitting just Receiving. Please let me know.. Thanks

~~kb2vxa~~ · #4 (**permalink**) 12-23-2012, 6:18 PM

For 12V a computer supply is only suitable for low current applications like running the cooling fans. Radios in receive mode draw little current so the Astron is sufficient to handle a 50W transmitter plus the others receiving, just not more than one transmitting.

n8emr · #5 (**permalink**) 12-23-2012, 7:42 PM

Quote:

Originally Posted by kb2vxa

For 12V a computer supply is only suitable for low current applications like running the cooling fans. Radios in receive mode draw little current so the Astron is sufficient to handle a 50W transmitter plus the others receiving, just not more than one transmitting.

While you do have to content with the 12v vs 13.8v issue, modern computer power supplies can deliver a fair amount of current. some int he 15-20 amp range, Look at some of 750watt and up server power supplies and you can get 50amps at 12v..

~~kb2vxa~~ · #6 (**permalink**) 12-24-2012, 12:04 AM

I have a 750W PSU and not one of the wires will handle anywhere near 50A so I think Antec may disagree with you. That having been said and the OP's question answered it's time to move on.

NDRADIONUT · #7 (**permalink**) 12-24-2012, 1:23 AM

Several 12v wires together will increase the amperage...several 12v supplies i have are adjustable and will put out 13.8v or even up to 16v.....

k3cfc · #8 (**permalink**) 12-24-2012, 6:28 AM

Quote:

Originally Posted by thereverend2u2

I was wondering if it is at all possible to use 1 COMPUTER POWER SUPPLY. to power my 5 12 volt units that i want to build a box for so i can have them all stacked in one nice looking rack. Has anyone done this and how is it done? How do i switch the power supply on and off etc?? Diagrams welcome..

MERRY CHRISTMAS TO ALL!

Take a look at your pm for some interesting information.

prcguy · #9 (**permalink**) 12-24-2012, 7:51 AM

There was a magazine article, either QST or 73 that showed how to make a computer power supply into a 13.8v unit at around 20A. They only need minor modification and the RF hash is very easy to tame.

I have a 40m net every weekend with the guy who wrote the article and I'll get more details.
prcguy

fineshot1 · #10 (**permalink**) 12-24-2012, 2:44 PM

ok guys - this has been tried and even Motorola could not get it right.
I am surprised moto even tried as i would have thought their engineers
would have known it was not worth the try.

They are poor performers for especially 50W radios and they burn up
after a certain amount of time.

Batboard • View topic - XTL Consolette Pwr Supply HPN4005B

twjr80 · #11 (**permalink**) 01-10-2013, 9:21 PM

I use an old computer power supply with my Yaesu FT-7800. I see full 50 watts of output on VHF. No issues with it for the past 4 years.

fineshot1 · #12 (**permalink**) 01-19-2013, 11:06 AM

Quote:

Originally Posted by twjr80

I use an old computer power supply with my Yaesu FT-7800. I see full 50 watts of output on VHF. No issues with it for the past 4 years.

I would bet you do not use yours 24 x 7 in a public safety environment
and that is why i posted the above link.

KE4NYV · #13 (**permalink**) 02-03-2013, 7:46 PM

We sell a product that not only allows you to turn the power supply off and on, but also breaks out the +3.3V, +5V, +12V and -12V voltages to the popular PowerPole connector:

http://www.rpc-electronics.com/ps.php

wa8pyr · #14 (**permalink**) 02-03-2013, 8:22 PM

Quote:

Originally Posted by thereverend2u2

I was wondering if it is at all possible to use 1 COMPUTER POWER SUPPLY. to power my 5 12 volt units that i want to build a box for so i can have them all stacked in one nice looking rack. Has anyone done this and how is it done? How do i switch the power supply on and off etc?? Diagrams welcome..

A typical computer supply will work just fine for applications up to 7 amps or so. Here's a how-to:

Mark-Rodgers.com: Convert Computer Power Supply to use for CB / Ham radio

I've used one in the past to power several receivers. Worked just fine.

jim202 · #15 (**permalink**) 02-03-2013, 8:42 PM

Quote:

Originally Posted by kb2vxa

I have a 750W PSU and not one of the wires will handle anywhere near 50A so I think Antec may disagree with you. That having been said and the OP's question answered it's time to move on.

Come on down from your soap box and take another thought about the computer power supplies. Yes the wires supplied won't handle the 50 amps output individually, but no one is saying that. If you think about how those supplies are used, there are multiple wires that carry the current to the different devices. If you add up all the connectors, I think you will find the current has been spread between a number of different wire connections.

Unless I missed the comment in the first post, the person asked if in receive only, will the supply be enough. If that is in fact the case, I would guess that each radio might pull 250 ma. So you could have a number of radios in receive working just fine.

As to the output voltage, if you open up the computer supplies, most of them have a voltage adjustment. I have found that you can indeed adjust the voltage up to 13 or 13.5 volts. Just remember if you do that, all the other voltages will go up also.

jim202 · #16 (**permalink**) 02-03-2013, 8:46 PM

Quote:

Originally Posted by fineshot1

ok guys - this has been tried and even Motorola could not get it right.
I am surprised moto even tried as i would have thought their engineers
would have known it was not worth the try.

They are poor performers for especially 50W radios and they burn up
after a certain amount of time.

Batboard • View topic - XTL Consolette Pwr Supply HPN4005B

You have got to be kidding that Motorola has engineers working for them. If they did, they would have used a larger power supply in the consolette stations. You can fry an egg on one of those with the radio just in receive.

jim202 · #17 (**permalink**) 02-03-2013, 8:51 PM

Quote:

Originally Posted by thereverend2u2

I was wondering if it is at all possible to use 1 COMPUTER POWER SUPPLY. to power my 5 12 volt units that i want to build a box for so i can have them all stacked in one nice looking rack. Has anyone done this and how is it done? How do i switch the power supply on and off etc?? Diagrams welcome..

MERRY CHRISTMAS TO ALL!

I believe that if you use an AT type power supply, it has a green wire in about the center of the connector. If you ground that wire, it will turn on the supply. Remove the ground and it will shut off.

Pape · #18 (**permalink**) 02-25-2013, 7:41 PM

Quote:

Originally Posted by jim202

I believe that if you use an AT type power supply, it has a green wire in about the center of the connector. If you ground that wire, it will turn on the supply. Remove the ground and it will shut off.

ATX pwr supp sir, AT are the one with a big on/off switch.

Read the information out of your pwr supp sticker it will tell you how much amp the 12v rail can supply
there is so much different pwr supp out there only way to know if it work is to try it out.

PS use the power from the molex connector not the MB connector and make sure you use the -12v ground cable