I have 2 computers in 1 computer case. Computer A and B both function as stand alone computers. They simply share a Mountain Mods UFO Duality 18" cube case.

I want to extend my current water cooling loop from computer A over to computer B.

The problem is that I want to use a single 12v pump. This 12v pump needs to turn on when computer A and/or computer B are turned on.

Is there a way that I can use a relay to switch the pump on when either computer is turned on?

Thanks for taking the time to read.

Jason

 

Take the 12v supply from each computer via a diode from each to the 12v pump.
The question is would the pump still run effectively with a diode drop in voltage?

 

That's what I'm worried about. I'm pushing the maximum components through this water loop already and I'm not sure if I can afford any less head pressure.

I have a seperate power supply that I was trying to figure out a way to power the pump through a relay that both computers could trigger. I just can't find a relay that has 2 seperate triggers for the same output.

Does such a component exist?

Thanks,
Jason

 

Where does the 12V that actually powers the pump come from?

If supply A is on; but supply B is off, then does A power the pump?
If supply B is on; but supply A is off, then does B power the pump?
If both A & B are on, who powers the pump?

 

I have a seperate power supply that I was trying to figure out a way to power the pump through a relay that both computers could trigger. I just can't find a relay that has 2 seperate triggers for the same output.

Does such a component exist?

Yes, it is called an OR gate.
You can create an OR function using two diodes as I have described before.
If you do not want to power the pump via a 0.7v drop across the diode, use the two diode solution to close the relay and turn ON the AC power to your external 12v supply.

 

I would just try the diodes with the pump directly first to see if it works ok. Use high current Schottky diodes to minimize the voltage drop.

If that doesn't work properly then use the diodes with the relay.