Water flow sensor

[BrilliantHome]

I'm outfitting my elderly mother's home with a series of sensors that allow me to track her activities. The system, which uses my own  software to analyze events & states, sends emails to my cell phone when something anomolous happens.

One of the things I need to track is whether she left the water running somewhere. For this I need a sensor that can detect that water is flowing in a pipe, and transmit a corresponding state message to the automation software system. I don't see anything cheap & readily available, so I've resorted to rolling my own.

My plan is to use a cheap EagleEye motion sensor (they're available in 3-packs for about $20 on Ebay) as the starting point. I would replace the pyro sensor with a remote microphone which would be affixed to the outside surface of a pipe near a point where water turbulance would cause a detectable sound. Next to the water meter or a valve would be likely monitoring points. I would modify the EagleEye circuit very slightly so that the output of the microphone would trigger an RF message, just as the output of the pyro detector would in the original EagleEye design.

The same technique could be used to measure that electric current is flowing in a wire (say the oven/stove) by using a hall-effect transducer in place of the pyro detector.

Am I re-inventing the wheel on this, and would anyone like to offer suggestions?

[EL34]

You could also put something like a solar pump housing only/ no motor in series with the water main.
The water would turn the pump cage and the shaft would turn.
You can measure the shaft turning.

Or maybe if you had the DC motor on the pump, would it generatea voltage?

Buddy of mine just gave me an older solar pump. Pretty simple inside and they are cheap.

On the electric deal, I have current sensors that just go around a wire.
When current flows through the wire, the sensor turns on a powerflash unit that then turns on X10 modules

[BrilliantHome]

EL34,

Thanks for the suggestion.

I'm trying to do this with a cheap wireless interface, thus the EagleEye foundation.

Yes, the hall-effect current sensor was what I had in mind for monitoring AC current

Joe