ATX Power Supply
Lázaro Menezes
- 2 minutes read - 415 wordsNew year, new hobby!
For 2021 I decided to start a new hobby, electronics, and, while learning, build something that I can use within one of the other hobbies. It’s planned to be an year-long project and I expect coming back here to write a couple of lines as it progresses. I’ll bring more details into the project in a next post.
But, before actually start the main project, I needed something that could help me with the prototypes, so I started building a prototyping tool: a bench power supply capable to provide different tensions, easily accessible within the protoboards.
I knew it was possible to achieve it using an ATX power supply, used in desktops, but I didn’t know exactly how although I knew wire colors had something to do with it :D.
After doing some research - see references below - it turned out it wouldn’t be as complicated as I was thinking. Basically, each wire color represents an kind of output, with some of them having special functions. The map below shows it.
Special wires
Most of the wires gives you a specific tension output when the power supply is on, from -12V to +12V but some of them have special functions. Let’s highlight some of them
Green - Power On
The green wire is used for turning on the power supply. This is done by grounding. If you want a switch, you need to put it between the green and any of the black wires:
Grey - Power Good
The grey wire is powered when the power supply is working. It can be used to turn a led on to indicate it. It’s needed to use a resistor within the LED for not plugging it straight to the power source.
Purple - Stand By
I didn’t use this one but it worths mentioning.
The purple wire is powered as long as the power supply is plugged in a power source - wall output, per example. It provides +5V and can be used to turn an indication led on, per example.
All Wirings
This is the final wiring. My ATX supply doesn’t have the white wire, -5.0V, so I ended up with an empty spot for now, but I might use it on a future upgrade :)!
Final result
References
Check up the folloing references I used for building this bench power supply
Making off
