Introduction: Recycled Power Supply

I needed a 12V power supply for a ham radio. It needed to be able to supply 10A intermittently and be cheap. I didn't want to purchase one so I went to the junk pile. I found a nice case that used to be a satellite receiver and a bare power supply board from a discarded computer peripheral. I have an ad on Craigslist for old printers and computers parts saying I will take them away for free. This is how I fill my junk pile.

Step 1: Mounting the Power Supply

After gutting the case I made a new face plate from a scrap piece of metal. Whenever I see a piece of ducting on the street I grab it and chop it into squares and add it to the pile. the same goes for microwave ovens and even dishwashers washing machines and dryers. My Jeep is more Maytag now than AMC....

its a tight fit but left room for a current shunt and the cute little volt/amp meter I had left over from another project.

I googled the part number and found a data sheet that said it is capable of starting up without a load. This is not common for many computer supplies but was a blessing to see. many times I just use an old fashioned incandescent pilot light and some fans to give the minimum start up load.

Step 2: Closing It Up

I didn't bother to make a new rear plate since you don't have to look at that all the time.

I added Binding posts for the main output and some small power jacks for accessory power.

Little things like this SWR meter can be powered with small jumper cables

Step 3: Load Test

I have a bunch of 12V car taillights soldered together using bare 14Ga copper wire.

They draw about 15 amps and come in handy for plenty of uses. Testing 12v supplies is the least of them.

they come in real handy to find intermittent shorts in a car. I just remove the blown fuse and replace it with these lights. then tug at the harness until the lights flash or flicker.

Step 4: Final Test

Works perfectly and shows no sag or problems from RF interference even sitting next to the radio.

At 50Watts out the radio draws about 7A so there plenty of power left for amplified speakers, cw filters and testing other 12v equipment.

Step 5: Other Options

Nothing says it has to be pretty.

I just used a grommet and 10mm LED to plug the original cord hole and added a couple of binding posts to a brick and there's an instant 12V 3.5A bench supply.

Then I took and old telephone speaker and added a small 12/5V supply and a fan and I have a simple supply to run computer drives on the bench.

I also found a multi output brick from an ancient Racal-Milgo modem. that provide +12(White), +5(Red), and -12V(green) outputs

I got these weird right angle plugs from MCM Electronics so you can turn the bricks into huge wall warts.

Comments

author
BeachsideHank (author)2014-08-21

You seem to know what you're doing, I'd be comfortable then
if you were given the remote launch codes for nuclear missiles with the promise
you'll wait for further instructions.

And a delightful, funny Instructable, B.T.W.

author
rjkorn (author)BeachsideHank2014-08-28

Thanks!

happen to have those codes handy????

author
BeachsideHank (author)rjkorn2014-08-28

I'll transmit them to your back molars, as usual. Don't forget to wear your aluminum foil lined hat to prevent government spies from intercepting this.

author
craftclarity (author)2014-05-28

I like how simple and clean it looks from the front...

author
rjkorn (author)craftclarity2014-06-02

That space in the center is begging for a sticker. I have some Avery clear labels but I don't want to mess up that clean look. Its hard not to put something there......

author
tomxu (author)2014-05-18

cool!

author
rjkorn (author)tomxu2014-06-02

Thank You

author
jedii72 (author)2014-05-12

Cool.

author
rjkorn (author)jedii722014-05-12

Thanks!. I'm going to build another tonight for use at work but this time use a +12V +5V hard drive supply.

author
jedii72 (author)rjkorn2014-05-12

I built this one and use it regularly. I like seeing what other people do with their power supplies. Let us know what else you come up with.

https://www.instructables.com/id/AT-ATX-Portable-Bench-Power-Supply-with-voltmeter-/

author
rjkorn (author)jedii722014-05-13

That's pretty nice!

author
nkapon (author)2014-05-12

well done!

author
rjkorn (author)nkapon2014-05-12

Thank You!

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