VOGONS


First post, by snorg

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For one of my builds I've been thinking about making a PSU switch that allows power to be applied to one of two motherboards, so I can have 2 systems in one case.

I think I would need a 2 position 12 pole rotary switch to do this (since there are 12 leads on an AT power supply cable, and I have 2 states I am switching between).

It would probably be bad to switch between the 2 while the system was running, I can't imagine it would be good. Any thoughts on an interlock system to prevent that? Maybe a separate switch to arm the rotary switch? Once a motherboard is selected, if the interlock switch is active the rotary switch is either prevented from moving or moving it doesn't accomplish anything? I could rely on myself to not be stupid about it but I am absent minded and worry I might toggle it if the systems are actively running. Not likely, but possible. I don't have any children, but if I were to exhibit the system I can see little fingers finding that a temptation.

Good idea? Bad idea? Not practical without a lot of additional work/wiring (I am pretty confident I can wire up the switch without an interlock system, but not in my ability to design a proper interlock).

Reply 1 of 3, by snorg

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I guess the best and safest option would be to use an external power brick to power one of the motherboards and then just use a KVM to switch between the 2, that makes way more sense and would be easier to deal with. But if anyone has a better idea let me know.

Reply 2 of 3, by BloodyCactus

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snorg wrote:

Good idea? Bad idea? Not practical without a lot of additional work/wiring (I am pretty confident I can wire up the switch without an interlock system, but not in my ability to design a proper interlock).

can you get a rotary switch capable of having 20A run through it? Ive never see a 12 pole switch thats cheap or can handle such amounts of current.

probably better idea is relays and use simple logic level ones, then just tie 5v +gnd to the switch, use that to trigger the relays.

something like this? I have not checked its specs to verify its validity. wire up maybe NO to one, NC to other... if you can trust these relays, they are 10A, if you dont pull 10A off any rail you might be ok

http://www.ebay.com/itm/232106661468

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Reply 3 of 3, by snorg

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That's probably one way to do it but I think using an external power brick with an AT adapter on the other end (or a pico PSU or something) is probably the way to go, then use a KVM to switch between the 2 systems. Now that I recall I started another thread a while back about the same/similar thing (sorry guys --- guess I need to check my posts better).