On Aug 28, 8:24*pm, "Rick Hughes" wrote:
It would be handy to be able to have a detector that can give an audible
signal when it starts to rain.

I often have sports kit outside drying (Scuba, boat etc) *and can't rely on
it staying dry long enough to dry kit.

I have found a link to one projecthttp://www.techlib.com/electronics/raindetectors.htm

Anybody anything better .... the key would seem to be the sensor ... large
enough surface are to catch first few drops of rain, stable enough not to
corrode in a couple of weeks.

These sort of circuits are generally kids' projects. If you want the
sensor to last you need to avoid any dc on the sensor, to avoid
galvanic corrosion. Generate ac and feed it to the sensor, using it
with another C or R as a voltage divider. Level of output voltage
drops when wet, use that to trigger your yes/no circuit.


NT