How to Build Your Own Variable Bench Power Supply Using an ATX Power Supply

Are you looking to build your own high wattage power supply? Are you looking to build it without having to spend money? Bench power supplies can cost you up to 250 dollars. This article will teach you how to build your own variable power supply using an ATX power supply from a computer. This comes in handy for students who are working on little projects at home and need a constant power source for their projects. This power supply will be able to give you a constant +5VDC,+12VDC,-12VDC and 1.2VDC-24VDC variable regulated voltage supply. On an average everything should cost about 50 dollars not including shipping charges. But it is still way cheaper then those 250 dollar supplies. Steps 1Unplug the power cord from the back of the computer.Make sure your computer is turned off first! 2Cut off the connectors.(Leave a few inches of wire on the connectors so that you can use them later on for other projects). 3Open up the power supply unit by removing the screws connecting the top and the bottom of the PSU case. 4Bundle wires of the same colors together.The color code for the wires is: Red = +5V, Black = Ground (0V), White = -5V (not used), Yellow = +12V, Blue = -12V, Orange = +3.3V (not used except if you have a brown wire in your supply, Purple = +5V Standby (not used), Gray = power is on (output), 5Start by drilling holes using a dremel tool or drill to the size of the banana jack post you are going to use.Also drill a hole for the LED, and also cut out square piece where the LCD will go and also drill room for a potentiometer with knob. 6Connect all the pieces together. *.Connect one of the red wires to the power resistor, connect all the remaining red wires to the red binding posts; *.Connect one of the black wires to the other end of the 10 ohm power resistor, one black wire to a resistor (330 ohm) attached to the cathode (shorter lead) of the LED and the other end of the LED (anode) connected to the gray wire,all the remaining black wires to the black binding post; *.Connect the +12VDC wires to the desired post( but leave one wire left alone so that you can use for variable voltage), the -12 VDC to desired post(the excess piece of wire cut and save for variable voltage section). *.Variable voltage binding should be left alone at this point and nothing should be soldered to it. *.Note some power supplies might have a brown sensing wire and or a pink wire. If you have a brown wire, solder it to the 3.3v orange wire and cut the rest out since you wont need to use them, and if you have a pink wire, solder it to the red wire. *.Please also notice the rubber grommets in the picture that are at the binding post. these are to be put on first then put on the nuts because this is to prevent metal nuts from making contact with the metal case so there for no shorting all the other binding posts together. 7Build the voltage regulator circuit. *.Using the components gathered, build the following circuit on a circuit board (if you need a datas