View source for Power Supply with an ATX PSU

[[Category:Closed_Projects]]

= Description =
Create a lab Power Supply from an [https://en.wikipedia.org/wiki/Power_Supply_Unit_%28Computer%29 ATX PSU].

= Components =

{| class="wikitable" style="text-align:left;"
|+ 
|-
! scope=col | Shop
! scope=col | Article N°
! scope=col | Description
! scope=col | Unit price (CHF)
|-
|Distrelec
|[http://www.distrelec.ch/borne-ronde-%C3%B8-4-mm-noir/ritel/24-15-003/100538/fr 100538]
|Laboratory socket black ø 4 mm
|4.-
|-
|Distrelec
||[http://www.distrelec.ch/borne-ronde-%C3%B8-4-mm-noir/ritel/24-15-003/100540/fr 100540]
|Laboratory socket red ø 4 mm
|4.-
|-
|Distrelec
||[http://www.distrelec.ch/borne-ronde-%C3%B8-4-mm-noir/ritel/24-15-003/100546/fr 100546]
|Laboratory socket green ø 4 mm
|4.-
|-
|Distrelec
||[http://www.distrelec.ch/borne-ronde-%C3%B8-4-mm-noir/ritel/24-15-003/100544/fr 100544]
|Laboratory socket yellow ø 4 mm
|4.-
|-
|Distrelec
||[http://www.distrelec.ch/borne-ronde-%C3%B8-4-mm-noir/ritel/24-15-003/100542/fr 100542]
|Laboratory socket blue ø 4 mm
|4.-
|-
|}


= 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

http://www.instructables.com/id/How-To-Build-A-Power-Supply-For-Electronics-Hobby/

= Pictures =
[[File:PSU_1.JPG|200px]]
[[File:PSU_2.JPG|200px]]
[[File:PSU_3.JPG|200px]]
[[File:PSU_4.JPG|200px]]

= 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. However, if the system uses a micro-controller (see Buck converter below), a digital screen could be an option. That would also be great to have a current limiter on that regulated output.

Linear regulators are excluded for this improvement because they dissipate way to much energy. A [https://en.wikipedia.org/wiki/Switched-mode_power_supply switch-mode power supply] approach is favored. So far, a [https://en.wikipedia.org/wiki/Buck_converter Buck converter] is considered.

= 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 =

{| class="wikitable" style="text-align:left;"
|+ 
|-
! scope=col | Shop
! scope=col | Article N°
! scope=col | Description
! scope=col | Unit price (CHF)
|-
|Distrelec
|[https://www.distrelec.ch/c%C3%A2ble-alimentation-atx-20-cm-24p-nt-20p-mb/maxxtro/aa-150-0613/679017/informatique/fr 679017]
|24-pin (NT) – 20-pin (MB)
|12.-
|-
|Distrelec
||[https://www.distrelec.ch/borne-ronde-%C3%B8-4-mm-gris-clair/ritel/24-15-001/100536/fr 100536]
|Laboratory socket light-gray ø 4 mm
|4.-
|-
|}