NeilP
1 GW
Now what i m about to say may be old news to some of you, but it's news to me and wish I had know before..so i shall post it here.
I have been building my own NAS boxes for years now, using FreeNAS and now NAS4Free, and recently come across an issue where my vanilla 350w PSU in the case I was using was just not man enough for 8 SATA drives plus pair of IDE's plus CD rom and associated fans...so what to do?
If you have a PSU that is under powered for you machine, be it a NAS box, or your gaming machine or whatever, you no doubt think about buying a bigger PSU..then you see the price.
Like me you may have a stack of old consumer 350 to 400 W PSU's kicking around, but nothing of a decent power rating
Well you can use more than one PSU to run the same PC.
I now have my box running with two separate PSU's, been like that for a week or more now.
Before you do this...google it yourself to look up any potential risks. I am not holding your hand.
But the basics:
make sure they are all on a common ground, so common power coming in to the machine and ground a black from each of the PSU's to each other
DON'T parallel the outputs.
Use one PSU for mainboard and all connectors on that.
If you have powerful gaming machine with fancy high power graphics cards..I believe it is OK to run the graphics card from a separate PSU...but I have nto tried it..I don't have anything like that..but Google it to be sure..pretty sure it is OK, but don't blame me if you do not do your own research.
I have mine setup with original PSU running the mainboard, CD -ROM, IDE HDD,and Fans connected to the main board.
Aux case fans and the bank of 6 SATA HDD's are running from a separate PSU.
The trick is getting the second PSU to start when you start the first one from the power switch.
Various ways, but all revolve around the green wire and one black wire on the mainboard 20 or 24 pin plug.
The green wire needs to be shorted to ground to start the PSU .
This can be achieved in various way
1) Easiest is just a paperclip. On the second aux PSU, simply put a paper clip between the green and a black pin. May not come back on when disconnecting ht emain spower though , so needs to be done each time mains power is removed
2) Add a switch. Cut the green and a black near the plug on the second PSU..not the one connected to the mainboard. Connect a switch between the two.
3) Connect the green wire from the aux PSU to the green wire of the main psu, connect a black from aux PSU to black on the main psu. Not treid thsi one personally, but have readt that it works. Cant see why not.
4) Preferred method. Connect a 12v (automotive will do) relay between a yellow and black wire form the probably redundant floppy drive lead. Connect the switch side of the relay to the green and black wire on the second PSU.
Cut off and and prevent shorting of any spare leads you do not need from the aux PSU, such as the mass of wires going to the 20 or 24 pin plug. Watch out for pins on that plug that have two wires going to them..if you find some like this, cut them out the plug and short them together, and insulate.
I do all my cuts and joints by solder and heat shrink but not necessary as long as you make a neat job with twisting and insulation tape.
If you want to get fancy, then open up the PSU, and unsolder all the spare wires direct at the board.
Good luck
I have been building my own NAS boxes for years now, using FreeNAS and now NAS4Free, and recently come across an issue where my vanilla 350w PSU in the case I was using was just not man enough for 8 SATA drives plus pair of IDE's plus CD rom and associated fans...so what to do?
If you have a PSU that is under powered for you machine, be it a NAS box, or your gaming machine or whatever, you no doubt think about buying a bigger PSU..then you see the price.
Like me you may have a stack of old consumer 350 to 400 W PSU's kicking around, but nothing of a decent power rating
Well you can use more than one PSU to run the same PC.
I now have my box running with two separate PSU's, been like that for a week or more now.
Before you do this...google it yourself to look up any potential risks. I am not holding your hand.
But the basics:
make sure they are all on a common ground, so common power coming in to the machine and ground a black from each of the PSU's to each other
DON'T parallel the outputs.
Use one PSU for mainboard and all connectors on that.
If you have powerful gaming machine with fancy high power graphics cards..I believe it is OK to run the graphics card from a separate PSU...but I have nto tried it..I don't have anything like that..but Google it to be sure..pretty sure it is OK, but don't blame me if you do not do your own research.
I have mine setup with original PSU running the mainboard, CD -ROM, IDE HDD,and Fans connected to the main board.
Aux case fans and the bank of 6 SATA HDD's are running from a separate PSU.
The trick is getting the second PSU to start when you start the first one from the power switch.
Various ways, but all revolve around the green wire and one black wire on the mainboard 20 or 24 pin plug.
The green wire needs to be shorted to ground to start the PSU .
This can be achieved in various way
1) Easiest is just a paperclip. On the second aux PSU, simply put a paper clip between the green and a black pin. May not come back on when disconnecting ht emain spower though , so needs to be done each time mains power is removed
2) Add a switch. Cut the green and a black near the plug on the second PSU..not the one connected to the mainboard. Connect a switch between the two.
3) Connect the green wire from the aux PSU to the green wire of the main psu, connect a black from aux PSU to black on the main psu. Not treid thsi one personally, but have readt that it works. Cant see why not.
4) Preferred method. Connect a 12v (automotive will do) relay between a yellow and black wire form the probably redundant floppy drive lead. Connect the switch side of the relay to the green and black wire on the second PSU.
Cut off and and prevent shorting of any spare leads you do not need from the aux PSU, such as the mass of wires going to the 20 or 24 pin plug. Watch out for pins on that plug that have two wires going to them..if you find some like this, cut them out the plug and short them together, and insulate.
I do all my cuts and joints by solder and heat shrink but not necessary as long as you make a neat job with twisting and insulation tape.
If you want to get fancy, then open up the PSU, and unsolder all the spare wires direct at the board.
Good luck
