Main Restorations Software Audio/Jukebox/MP3 Everything Else Buy/Sell/Trade
Project Announcements Monitor/Video GroovyMAME Merit/JVL Touchscreen Meet Up Retail Vendors
Driving & Racing Woodworking Software Support Forums Consoles Project Arcade Reviews
Automated Projects Artwork Frontend Support Forums Pinball Forum Discussion Old Boards
Raspberry Pi & Dev Board controls.dat Linux Miscellaneous Arcade Wiki Discussion Old Archives
Lightguns Arcade1Up --- Bug Reports --- Site News

Unread posts | New Replies | Recent posts | Rules | Chatroom | Wiki | File Repository | RSS | Submit news

  

Author Topic: Need help! How to get -5v out of newer ATX Power Supply's  (Read 1051 times)

0 Members and 1 Guest are viewing this topic.

Savannan

  • Trade Count: (+1)
  • Full Member
  • ***
  • Offline Offline
  • Posts: 183
  • Last login:December 22, 2012, 10:53:06 pm
Need help! How to get -5v out of newer ATX Power Supply's
« on: September 23, 2011, 05:10:09 pm »
Hi all...

I need help...I picked up a cosair 600w power supply today for my multi-mk cab.   Everything was going good but I was looking at the Pinouts on the 24pin connector and it doesnt have -5v pin.  /cry   

I looked at wikipedia and found this
----------------------------------------
Pin 20 (formerly −5V, white wire) is absent in current power supplies; it was optional in ATX and ATX12V ver. 1.2, and deleted as of ver. 1.3.

---------------------------------

Is there a mod that I can do get achieve -5v out of this power supply? Or would I have to buy a older P/S?

Thanks!!!!!

Sav

BobA

  • Trade Count: (+14)
  • Full Member
  • ***
  • Offline Offline
  • Posts: 5943
  • Last login:July 11, 2018, 09:52:14 pm
  • What Me Worry?
Re: Need help! How to get -5v out of newer ATX Power Supply's
« Reply #1 on: September 23, 2011, 06:30:48 pm »
You can use a -5v regulator to get 1A -5V from your -12V supply.

Google LM7905

 :D

Thenasty

  • Trade Count: (+16)
  • Full Member
  • ***
  • Offline Offline
  • Posts: 4275
  • Last login:Yesterday at 03:16:10 pm
    • Thenasty's Arcademania Horizontal/Vertical monitor setup.
Re: Need help! How to get -5v out of newer ATX Power Supply's
« Reply #2 on: September 23, 2011, 09:46:43 pm »

Or would I have to buy a older P/S?

Thanks!!!!!

Sav

No need to buy

http://forum.arcadecontrols.com/index.php?topic=101280.0

also in the FREE Section
Thenasty's Arcademania Horizontal/Vertical setup.
http://forum.arcadecontrols.com/index.php?topic=26696.0

Free VGA Breakout Cable
http://forum.arcadecontrols.com/index.php?topic=38228.0

Ultimate All in One Coin Mech write up (Make your own)
http://forum.arcadecontrols.com/index.php?topic=19200.0

Franco B

  • Trade Count: (+10)
  • Full Member
  • ***
  • Offline Offline
  • Posts: 3766
  • Last login:August 21, 2020, 12:37:46 pm
Re: Need help! How to get -5v out of newer ATX Power Supply's
« Reply #3 on: September 24, 2011, 04:46:00 am »
For Jamma boards that require -5v I have used a Negatron wired to a Jamma pass-through. It may not be the solution for you but its worth noting for reference.



 

Savannan

  • Trade Count: (+1)
  • Full Member
  • ***
  • Offline Offline
  • Posts: 183
  • Last login:December 22, 2012, 10:53:06 pm
Re: Need help! How to get -5v out of newer ATX Power Supply's
« Reply #4 on: September 24, 2011, 10:17:49 am »
whta does that negatron do?

Franco B

  • Trade Count: (+10)
  • Full Member
  • ***
  • Offline Offline
  • Posts: 3766
  • Last login:August 21, 2020, 12:37:46 pm
Re: Need help! How to get -5v out of newer ATX Power Supply's
« Reply #5 on: September 24, 2011, 10:31:18 am »
Its a DC-DC convertor. You can input 4v to 14v and output -1.3v to -12v

I have the input wired to the 12v of the Jamma edge and the output set to -5v and wired to the -5v pin which provides 0.5A

I used it for games that require -5v for the audio amp as the PSU I had didn't supply -5v.

More details [here]

Savannan

  • Trade Count: (+1)
  • Full Member
  • ***
  • Offline Offline
  • Posts: 183
  • Last login:December 22, 2012, 10:53:06 pm
Re: Need help! How to get -5v out of newer ATX Power Supply's
« Reply #6 on: September 24, 2011, 11:15:53 am »
Wow..it sounds like its the thing I need..
But just wondering if it will work if I soldered that to my main jamma harness...plugged it into my 6 in 1 switcher and ran a midway game....?  Hmmm...
It would suck If I need one of these per game.

Sav

BobA

  • Trade Count: (+14)
  • Full Member
  • ***
  • Offline Offline
  • Posts: 5943
  • Last login:July 11, 2018, 09:52:14 pm
  • What Me Worry?
Re: Need help! How to get -5v out of newer ATX Power Supply's
« Reply #7 on: September 24, 2011, 02:20:01 pm »
A negatron costs about $20 and if you need one for each board it is quite pricy.  An LM 7905 is about $2 and with the 2 caps needed comes in less than $3.

Franco B

  • Trade Count: (+10)
  • Full Member
  • ***
  • Offline Offline
  • Posts: 3766
  • Last login:August 21, 2020, 12:37:46 pm
Re: Need help! How to get -5v out of newer ATX Power Supply's
« Reply #8 on: September 24, 2011, 04:36:30 pm »
I don't suppose you could provide a wiring diagram/parts list for the LM 7905 solution could you BobA, I would love to see it.

BobA

  • Trade Count: (+14)
  • Full Member
  • ***
  • Offline Offline
  • Posts: 5943
  • Last login:July 11, 2018, 09:52:14 pm
  • What Me Worry?
Re: Need help! How to get -5v out of newer ATX Power Supply's
« Reply #9 on: September 25, 2011, 02:01:49 am »
I don't suppose you could provide a wiring diagram/parts list for the LM 7905 solution could you BobA, I would love to see it.

Here is the data sheet with sample circuit.