Under Water Sound Project

Thread Starter


Joined Jan 28, 2014
Hello, I am currently working on a new product that requires a sound to be produced from small/thin waterproof speakers. The product is powered by a hydro turbine and micro-generator. The product will have the ability to be turned on and off but when it is turned on I would like it to produce the sound only when submerged.

Are there sensors that will detect when an object has been submerged to then signal the speakers to produce the sound?

Any help would be much appreciated!

Thank you.


Joined Apr 24, 2011
The sensor can be as simple as a single MOSFET and a resistor: use 100K plus to pull the gate up, make sensor leads connected to ground and the gate. Ground source, and the drain becomes a connect to ground in water switch.

Some ESD protection for that gate would be a good thing, or get it free from inside any CMOS gate.