{"id":5433,"date":"2019-02-02T12:06:06","date_gmt":"2019-02-02T17:06:06","guid":{"rendered":"https:\/\/dronebotworkshop.com\/?p=5433"},"modified":"2023-04-11T17:40:19","modified_gmt":"2023-04-11T21:40:19","slug":"atx-bench-supply","status":"publish","type":"post","link":"https:\/\/dronebotworkshop.com\/atx-bench-supply\/","title":{"rendered":"Convert an ATX Computer Supply to a Bench Power Supply"},"content":{"rendered":"\n

\"Download \"Parts<\/a> \"View<\/a><\/p>\n

Introduction<\/span><\/h2>\n

Every workbench should have at least one power supply.<\/span><\/p>\n

When you\u2019re experimenting with electronics and microcontrollers a good power supply can be an essential piece of equipment. While you can certainly make do with USB power bricks and \u201cbattery eliminators\u201d nothing beats having a dedicated power supply with plenty of voltage selection and current capability.<\/span><\/p>\n

<\/div>\n


\n<\/span>An ideal workbench power supply should have both 5-volt and 12-volt outputs, with 3.3-volts being a nice option as well. It should be capable of providing several amperes of current for each voltage.<\/span><\/p>\n

You can buy bench power supplies of course, but they are not inexpensive. As the current capability and number of output voltages go up so does the price.<\/span><\/p>\n

While a commercial bench power supply is certainly a worthwhile investment there is a cheaper solution that you might want to consider. Adapt an old computer power supply to use on your workbench.<\/span><\/p>\n

\"Convert<\/p>\n

Computer power supplies have all the voltages you\u2019ll need and some very impressive current capabilities. And, thanks to mass production, they are cheap when compared to dedicated bench power supplies.<\/span><\/p>\n

In fact, if you have access to an old computer that is on its way to the junk heap you can rescue its power supply and put together a nice bench power supply for just a few dollars.<\/span><\/p>\n

That\u2019s what I did actually – an old Windows XP desktop computer has now become a useful addition to my workshop.<\/span><\/p>\n

ATX Supply<\/span><\/h2>\n

ATX (<\/span>Advanced Technology eXtended<\/span><\/i>) is a computer motherboard configuration developed by Intel in 1995. \u00a0It still is the most common motherboard configuration.<\/span><\/p>\n

ATX Power supplies have standard sizes and connectors for use with ATX motherboards. There are actually a few different ATX power supplies, all of them are designed to provide 3.3, 5 and 12 volt outputs.<\/span><\/p>\n

Main Power Connector<\/span><\/h3>\n

The main power connector supplies power to the motherboard of the computer. It also has connections for power switches and indicators.<\/span><\/p>\n

There are two types of connectors commonly used here, an older 20-pin variety (Version 1) and a newer one (Version 2) with 24-pins. Both use Molex connectors.<\/span><\/p>\n

The unit I will be experimenting with uses an older 20-pin power supply connector.<\/span><\/p>\n

Here are the two power connectors.<\/span><\/p>\n

\"ATX<\/p>\n

Note that the primary difference is that the 24-pin connector has additional voltage and ground lines.<\/span><\/p>\n

You\u2019ll notice that many connections (i.e. ground) have been repeated, this is done to increase the current carrying capability. \u00a0The actual connections from the power supply are as follows:<\/span><\/p>\n