H2o flow switch

I recently built a water flow switch and am looking for a way to drop out power if my pump fails.

I would like to output to a relay to turn off my rig if my water flow drops out. Any suggestions on how to make this work perferably without cutting into psu lines?

Here is the link to "how to build switch"
http://www.overclockers.com/tips642/

Hello there, I was interested in something similar a while back, had a thread on my idea here..
http://forum.oc-forums.com/vb/showthread.php?s=&threadid=48355

Anyway, that design looks over complicated, if you have a big enough magnet swinging free, a simple way to implement power off would be to use a reed switch as well/instead of the hall effect sensor. You could wire a 5v or 12v circuit through it to trip off a relay in the power cable to your PC. The relays coil would be 5 or 12 V and the contacts rated at wall voltage at sufficient amps for your PSU.

Myself, I wouldn't care if I lost data, I'd just want the power off NOW if there was a problem.

regards,

Road Warrior

welcome to the forums by the way

Interesting idea R.W. the link I posted was for anyone interested in the concept of flow switches, I took it a step further by milling 2 pcs of 1/2 in lexan and sandwiched together, with a swinging magnet and a prox switch. I'm also adding LEDS since it is see through and looks sharp. My cooling rig has an external pump, heat exchanger and an old AT PSU. I could very easily run my output from the relay to drop out my ATX PSU. But this seems too... how do you say... common? After brainstorming an idea I have would be to use the on/off header pins on the mobo and momentarily complete the circuit to do a soft shutdown
((ON SWITCH)short the pins once turns your computer on)
((OFF SWITCH)short the pins once more turns it off) However this is a soft shutdown and can take too long i.e 10 seconds.
Anyone know how to speed up a soft shutdown?
I've tried the instant shutdown setting in BIOS and in Win2000 but does not seem to speed up the shutdown.

Any ideas or suggestions would be great.

Tap into the PSU "power good" wire. If you break this connection, everything should shutdown rather quickly

Theres a circuit out there somewhere (i have it on file at home) where someone took a thermal switch and hooked it up to that wire. If the pump failed, and the block rose in temp enough to trip the switch, the PC shut off immediately.

Do you have the pin # for the power good wire? This may be what I'm looking for

its the fourth from the left on the side with the clip, its green, on the right of it is a black wire and on the left is black, then blue, then orange, when you turn on your computer, the mobo grounds this wire (it connects it to one of the various black wires on the connector), this is also how you also start a psu without a mobo