Revision as of 23:06, 15 December 2011

Status

On going...

Description

Create a lab Power Supply with an ATX PSU

Components

Price

Depends of connectors number and of availability of an old working ATX PSU.

Voltage

• +5VDC
• +3.3VDC
• +12VDC
• -12VDC

People involved

• Fred
• Speredenn

Links

http://www.semageek.com/diy-transformer-une-alimentation-atx-en-alimentation-de-laboratoire/

http://pinouts.ru/Power/atxpower_pinout.shtml

http://www.sinux.net/2011/09/alim-atx.html

Pictures

Update: PSU with regulate output

It is a better idea to have the ATX set up in a box and to use the ATX connector to connect to the banana plugs. Basically, it is then possible to have the 5 usual plugs (GND, +3.3, +5, +12, -12) and add a regulated output (0-12V). The visualization for that regulated output can be analogical.

That would be great to have a current limiter on that regulated output also. Linear regulators are excluded for this improvement because they dissipate way to much energy. A switch-mode power supply approach is favored <https://en.wikipedia.org/wiki/Switched-mode_power_supply>. So far, a Buck converter is considered : https://en.wikipedia.org/wiki/Buck_converter

Options

I suppose it is good to have at least 2 LEDs, a red and a green, each with a 220Ω resistor in series. turning on the PSU can be done with a SPDT switch, that is: on1 - on2.

• red LED is between on1 and purple (standby 5V)
• green LED is between grey (power OK) and on2 (or GND, for that matter)
• green cable is soldered onto on2
• middle point of the SPDT switch is on GND

this has the following consequences:

• when PSU is on mains and switched off, the red LED is on
• when flipping the switch, PSU turns on ; after about a second the green LED lights, indicating all is good.

I feel like wasting time, so here's some crappy ASCII art for this:

green-----------------
            (grn)    |
grey----R----|>|--o  o--------ON2
                  |          /      ←{ this here is the SPDT switch }
GND---------------o--------o/
            (red)
purple--R----|>|--------------ON1

Components