Awesome Bench Power Supply

Step by step instructions to build what according to my cousin (7 years old but smart like a 8) is: "The best homemade bench power supply starting from a PC power supply present on instructables".

First you have to ̶s̶t̶e̶a̶l̶ find a fixed PC power supply, better if you find one that works and that has the ON-OFF button on the back (̶t̶̶̶h̶̶̶e̶̶̶ ̶̶̶o̶̶̶n̶̶̶e̶̶̶ ̶̶̶f̶̶̶r̶̶̶o̶̶̶m̶̶̶ ̶̶̶1̶̶̶9̶̶̶9̶̶̶8̶̶̶ ̶̶̶t̶̶̶h̶̶̶a̶̶̶t̶̶̶ ̶̶̶y̶̶̶o̶̶̶u̶̶̶r̶̶̶ ̶̶̶f̶̶̶a̶̶̶t̶̶̶h̶̶̶e̶̶̶r̶̶̶ ̶̶̶s̶̶̶t̶̶̶i̶̶̶l̶̶̶l̶̶̶ ̶̶̶i̶̶̶n̶̶̶s̶̶̶i̶̶̶s̶̶̶t̶̶̶s̶̶̶ ̶̶̶o̶̶̶n̶̶̶ ̶̶̶c̶̶̶a̶̶̶l̶̶̶l̶̶̶i̶̶̶n̶̶̶g̶̶̶ ̶̶̶P̶C̶ ̶̶̶w̶̶̶i̶̶̶l̶̶̶l̶̶̶ ̶̶̶b̶̶̶e̶̶̶ ̶̶̶f̶̶̶i̶̶̶n̶̶̶e̶̶̶) .

Mine is a: DUAL FAN POWER SUPPLY NILOX 450W

After that to replicate my project you need (url links below) :

-1x ON-OFF switch (if you can't find the same switch, you can always edit or adapt the 3D file)
-1x GREEN Led
-1x RED Led
-4x BANANA JACK
-1x MINI DIGITAL AMP and VOLT display
-1x VOLTAGE REGULATOR DC-DC IN4-40V OUT1.25-36V
-1x USB female
-1x 12 POSITION SELECTOR
-1x Resistence 10W 47ohm
-2x Resistence 330 omh

-1x 3D project available on THINGIVERSE

and tools such as soldering iron, scissors, screwdrivers, cables, heat shrink tubing, patience amd a lot of bad words.

Before start assembling, print the walls of the power supply with a 3D printer.
Here's the link in thinghiverse: POWER BENCH SUPPLY_THINGIVERSE
If you don't have a 3D printer I also attach a sheet with all the measurements (and then don't say I leave something behind).

I sincerely suggest to try to fit all the walls' parts because, depending of the printer settings, it will can be necessary to work a little with glass-paper to make the joints easier.

Once printed and tested, also insert the components to check the dimensions and start the wiring.

Needless to say, but obviously all the following operations has be done without power.

If you have just tried the power supply testing all the outputs, remember that there are capacitors and that therefore, even disconnecting the current, there could be residual currents. If darwin's law has not run its course we can start with the first real operation.

1. Cut all the connectors to the maximum distance and roll the wires by same color
   • Red wires = +5V
   • Purple wire = +5VSB
   • Orange wires = +3V
   • Yellow wires =+12V
   • Black wires = GND
   • Green wire = On-Off
   • Grey wire = Not used
   • Blue wire = Not used

2. In my case for 3D printer I inserted a lightning bolt in the upper part, if you want to illuminate it, connect some LEDs in series and weld them together, we will connect them later.

Here an electrical scheme of the connections:

Taking care to weld the components where necessary and always use the insulation socks, the wiring passages are:

1. Connect the On-Off main switch to the Green wire and a Black wire.
2. Connect a Red wire to the ceramic resistance 10W 47 omh to make the 5V stable. Glue the resistor to the aluminium case to help the cooling.
3. Connect the rotative switch:
   • Connect one Orange wire to the pin 10 of the rotative switch.
   • Connect one Red wire to the pin 9 of the rotative switch.
   • Connect one Yellow wire to the pin 8 of the rotative switch.
   • Cut some portion of the Purple wire. Merge them and connect them to the pin 7 as the picture above.
4. Take the connector with 3 wires of the AMP-VOLT display:
   • Connect the White wire to the central pin A.
   • Connect the Red wire to a Red wire from the rolled wires.
   • Connect the Black wire to a Black wire from the rolled GND wires.
5. Connect an Organge wire to the anode (+) of the Green led through a 330 omh resistance (in the image it has been welded and is inside the insulating sock).
6. Connect the Purple wire from the rotative switch to the USB port on the + pin.
   • in this way the USB port will remain active even if the main On-Off switch it's turned Off.
7. Make a bridge with a 330 omh resistance to the Yellow Led's anode (+).
8. Make a bridge with the two Led's catodes (-) and the GND of the USB port connecting them to a Black wire.

Thanks for getting to the bottom of this guide, if you have only read it, it's perfect as it means nothing has burst and I am happy with that. If you have also built a power bench taking a cue from mine (and nothing has exploded) put ahere a few photos or it didn 't happend you know ;). Otherwise if something explode following my guide, i had to say that it's for sure your fault and i'm actually in a lone island of bahamas with my advocate so don't try to contact me (please).

And a big THANK YOU to Sorin DIY for the input and the idea! Practically the whole project is a copy paste of this video with some "artistic homage" made by me...but these are only details...no one likes details no? (I'm joking..Thank you very very much Sorin)

Cheers mate!