how to activate second PSU?

i want a second PSU for all the fans in the case... but my problem is how can i turn it on? i mean for a psu to actually transfer power to thepower cords it needs that on/off switch shortage between the pins on the mobo...

so if no mobo .. how can i do that?

thanks

Ground the green wire whenever you want the PSU on.
Note that some PSUs expect a load and therefore consider no load as a fault condition. Try adding some loads if it doesn't work.

Get a toggle switch and connect it to the green wire and a ground and flip the switch.

another thing you can do is connect the green wire to the green of the other ATX connector. Two ways to do this (i'll make my own variations )

The ***** way:

Get two ATX connector extensions. Connect each to the ATX leads of each PSU. Cut the GREEN wire in the middle of each extension. strip and tin them. Solder the green wire from the first ATX extension to the second ATX extension's green wire. plug in the first ATX extension, and it SHOULD work.

the non-***** way:

Instead of getting extensions, cut the wires off of the actual PSU's wires.

btw, SyberClock, who drew your avatar? It's really good, I like the style

SybrCLocK said:

i want a second PSU for all the fans in the case... but my problem is how can i turn it on? i mean for a psu to actually transfer power to thepower cords it needs that on/off switch shortage between the pins on the mobo...

so if no mobo .. how can i do that?

thanks

Click to expand...

Please see above sticky Dual PSU How-Tos that should give you all the info you need. I did this one about a year ago and my system is still running flawlessly.





If you have any questions feel free to PM me.

uhh thanks thats exactly what i needed and Electrons looks beutifull

the avatar: a friend sent it to me becouse it looks like me.. so i dont know who drew it...but i loved the manga style hair and glasses too

i dont think connecting them serial would be good becouse you get extra fluctuation on the diferent lines (12v, 5v, 3.3v)

thanks again

There is another way, without using extensions.
Get 12v 12v relay from radio shack or any auto parts store (used for fog lights), connect the switched leads to the green and black wires fron the secondary psu's atx plug. Then power the other two leads with any molex 12v (butcher a fan connector for readymade harness).
When the primary psu comes on, it will turn on the relay which effectively attaches the green to black of the secondary psu, turning it on. The devices attached to it will provide the load.

You can also use this psu to power other things like cd drives, lights etc to save the primary psu for the motherboard and main harddrive only...more power available for that monster overclock.

The extension way is nice, but I don't like the power loss from the connector the psu comes with, let alone using double connectors on the power line.
I'm just cranky that way 8)