Flow sensor

Pyrotom

On a recent project (control system for the solar hot water heater on my house in Jamaica) I needed a flow sensor. Most of the ones I could find on the net were way too expensive. Some of the overclocker sites had plans for building ones for use on water cooling systems for overclocked computers. I was about to go that way when I came across this flow sensor:
<http://www.allelectronics.com/make-a-store/item/UFS-1/UNIDENTIFIED-FLOW-SENSOR/1.html&gt;
With the help of some folks here I figured out how to use it. So if you're projects, either current or future, might need a flow sensor, I'd try to scarf one of these up before thay are all gone - the site says their stock is low. A diagram of how mine is wired is shown below. I just connected the signal line to a Prop pin through a 1K resistor and used one of the counters as a leading edge detector to count the pulses coming from the flow sensor. Works like a charm!

lfreeze

Please tell me what the resolution of the sensor is, (gallons or quarts ·per minute)? I think I

might have an application for an aquarium· or pond filtering system. ·They are so cheap

at $3 , I'm going to pick up a few.

Thanks

Larry

Pyrotom

I don't know. The sensor has a little paddle wheel inside that turns with the liquid flow. A photo-sensor detects the passing of the spokes on the paddle wheel. My application only needs to know wheter there is flow or not, so I have not experimented with trying to calibrate it.

lfreeze

Thanks for the response. It would have been interesting to experiment with, but they are sold out.

Larry