I have 2 Computer Power Supplies (PSU's) that I hooked together in Series to make a variable Voltage Power Supply. Going from 3 volts to 24 Volts DC. In Positive and Negative Ground, either way. But, it just sits under my Desk. Without an Enclose. With wires going everywhere. And it would be difficult to even move it, without the connections falling apart. Since my Resistors and Wiring Connections are just Bare Wires jammed into the Connectors. It works, just fine. But, I would like to do something like what Chris Osborn has done in this Project. His, enclosure is made of Wood. And it was fast and easy to build. He had Dado's in his pieces to make it easy to slide in the Front Panel or even replace it later, when he makes changes. I'm not sure if he cut his own Dado's. But, looks to me like some Pre-Made Drawer Stock would make this job even easier. And he actually found the Connectors and Parts to make the Connections easier too!:) Check out, this Project and more info and links below...

Update 12-08-15:

This is my original Post on Building my Power Supply Amp. Before I built it and put it in the Computer Case. I need to make an updated Post. When I have time. With my Build Pics. I could make a Video, by viewing the best Pics, in Gwenview, in Full Screen. While making a Desktop Video and Narrating it. I did Post the Pics, I have on flickr.com. My best Pics are at, Don's Power Supply Amp Project, https://www.flickr.com/photos/dweb98/albums/72157659308193109. And they can be viewed as a Slide Show, too. Here's the Sharing Link, https://flic.kr/s/aHskmqLBrx.

Don

Published on | Jul 12, 2010 | by Chris Osborn

Left my power supply at work, so I had to build a new one

I meant to bring home my power supply this weekend, but I forgot and left it at work. It was the motivation I finally needed to build a new one. I had been thinking about it for a long time, but since the old one still works, there wasn't any real reason to do it.

My old AT power supply My old power supply is a modified AT power supply. It was easier to work with because of the way the power switch was wired. In fact, after removing the huge bundle of cables, the hole was the perfect size for a switch from Radio Shack. But it was also the last AT supply I had, so if it ever died I wasn't going to easily make another. And if it ever died, I would have to go to a lot of trouble to make a new one. On the old one I opened it up and removed a lot of wires, drilled holes in the sheet metal case, and soldered in new jumpers to the binding posts. The other thing I didn't like was with the binding posts on top, I couldn't exactly stack things on top of it or fit it into a nice bench setup with easy access.

My new ATX power supply The new power supply uses an ATX power supply. An ATX supply doesn't turn itself on the same way, it's always in a sort of standby state and you have to short a lead to ground in order to get it on. Not quite as easy to modify, but not too hard either. I also wanted to leave all the wiring intact so that if it should ever die, or I ever wanted to upgrade it, I could swap it out.
Read More...
http://www.insentricity.com/a.cl/151/LeftMyPowerSupplyAtW

Here's an interesting PSU Adapter, mad by Mike. This entry was posted in Other Projects, Test Equipment by Mike.

Don

ATX Desktop Supply Adapter

ATX Power Supply Adapter

Posted on December 16, 2010

Built one of the ubiquitous ‘Desktop Power Supply’ from a recycled, ATX-form, PC power Supply. Actually used it occasionally to power a 12V charger in the garage. Unfortunately, it fizzled an electrolytic capacitor and it’s really not worth repairing.
So, I rescued all my hardware and built a reusable adapter for ANY standard ATX power supply.
Parts List:

Read More...
http://km5z.us/blog/?p=33

About Mike

I keep an electronics test bench and I love repairing old radios or building other electronic or amateur radio projects, usually late at night listening to shortwave or talking with other hams. My Amateur call sign is KM5Z.

Go to his Blog to see his other Projects...
http://km5z.us/blog/?author=1

Here's one of the Tutorials that I used in Converting my PSU's into a Desktop Power Supply. This is jut for using one PSU and it has the info on using Resistors to get the PSU to Power Up, without being Plugged into a Mother Board.

Don

Desktop Power Supply from a PC (PSU)

Updated March 13, 2009

A completed 145 watt ATX power supply with switch, binding posts, labels and feet. Notice the zip ties in the ventilation slots
that hold the load resistor.

If you find building your own desktop powersupply from a recycled PSU and a few parts from the local electronics store appealing, then grab some tools, pour yourself a cup of coffee (or personal preference) and let's get started. The LED (light emitting diode) was also salvaged from an old PC. If you want to add a power on indicator, LED's add a nice touch and can easily be wired into the +5v rail. I do strongly encourage you to read the contents of this site and associated links before beginning your conversion -- there are a number of hints included in the associated pages.

Excerpt from Page...

Power supplies in today's computers are known as SWITCHMODE or Switching Mode power supplies and require a load to continue to operate after being switched on (the term switching mode actually applies to the technique of A/C to D/C conversion and not to the power up action). This load is provided by a 10 watt, 10 ohm wire wound load resistor (sandbar - about $0.80 at Radio Shack) across the +5 volt supply. While many of the newer power supplies will Latch_On without a preload, you will find that adding the resistor will (1) increase the measured voltage on the 12 volt rail slightly and (2) help stabilize the voltage level in this rail by minimizing voltage drop when the powersupply is loaded with a charger. Some inexpensive power supplies may fail if forced on without a load although the Design Guide states that the supplies should not be damaged if run without a sufficient load.

		And, these Pages are the ones I used to learn now to Connect my 2 PSU's in Series to get 24 Volts DC out of them. As well as all of the standard lower voltages from 3 to 12 volts that a Computer Power Supply Produces... Don
		How to link multiple AT PSU's into one BIG PSU. By: OnDaEdg How to Run 2, 4, or even 10 (AT) Power Supplies In Parallel or Series at 5, 12, 18, or 24 Volts! Excerpts form the Page by OnDaEdg...

Now that we have everything we need, let's get to work. First off, I am going to give a bit of advice. Make sure they are unplugged. Also, there are high voltage capacitors inside these power supplies. DO NOT TOUCH THEM! They are in excess of 300 volts and can be very dangerous. If you are unsure as to what a capacitor is, you probably shouldn't go about attempting this modification for your safety's sake. This project is to be done at your own risk and myself or Procooling.com are not responsible for any injury or damage caused by improper use or modifications done to these supplies. I discharged these capacitors by placing a high watt/high ohm resistor across the capacitor leads. Back to the modification. If you plan on using two supplies, you only have to perform this modification to just one of them. If you plan on running three or more in parallel or series, you will have to perform the modification to all but one. I am using two so let's get one of these things opened up. Using a small Phillips screwdriver, I remove the four screws on the top.



	Now you can see those two capacitors on the right side that I warned you about. Be careful of them. The first and most important thing we have to determine is whether or not the negative side (black wires) are connected to case (3rd wire) ground. When I say case, I am referring to the actual metal case that the supply is sitting in. So how do we determine whether or not the negative side is connected to the case? We must perform either a continuity test (tells whether two points are connected by a conductive material) or an ohm reading using a multimeter. Either one of these tests will work Taking my multi meter, I touch one of the probes to the negative (black wires are negative) and the other probe to the case of the power supply.



	If the continuity test is positive, the multi meter will tell you (mine beeps). If you perform an ohm reading and it comes up 00.0 ohms, or very close to 0, then you have a floating ground as well. Then it is determined that the negative side is directly connected to the case. Most AT supplies within the last couple of years will more than likely have the negative connected to case. At any rate, the supplies I am using have the negative connected to case/3rd ground. Determining whether or not the negative is connected to ground is very important. This next part I am going to quote August Hoecker directly : "IF THE BLACK LEADS ARE COMMON TO CHASSIS GROUND IN THESE SUPPLIES AND YOU TRY TO CONNECT THEM IN SERIES OR PARALLEL THEY WILL SHORT OUT PERHAPS DAMAGING THE SUPPLIES!!!" Heh, you think he was trying to tell me something ? Now that we have determined that the negative is connected directly to the case, what do we have to do to be able to run two power supplies in series or parallel? Simply, we have to insulate or cut all of the connections to chassis ground. So let's find where the negative is connected to or touching the case. In order to do this, we have to unscrew the circuit board from the case and lift it up so we can see the bottom of it. First thing we use is our eyes. What we are looking for is a place where the negative side (black wires) is connected to the case. After not spotting any wires, I found where mine was touching the case. It was touching the case directly from the bottom of the copper clad circuit board to the raised mounting holes that accept the securing screws. Take a look for yourself:

Go there...
http://www.procooling.com/index.php?func=articles&disp=52&pg=1

Make a 24v Power Supply with 2 12v Server Power Supplies.

Here's a quick how-to on how to take 2 12v server power supplies and run them in series for 24v.

Read More...
http://www.rcgroups.com/forums/showthread.php?t=1431528#post18099804