Here is a simple high water sensor system to prevent costly to correct undetected water damage such as that caused by leaking pipes or corroded water heaters.
The high water sensor circuitry will detect any conductive non-flammable liquid, and it is triggered instantly by a moisture bridge across its sensor contacts.
The circuit uses 9V battery as the power source (V+). An external 9VDC power supply can also be used (DC IN). The drive output of the circuit (OUT) can be wired directly to a relay or can be used to actuate any external device such as an annunciator. The circuit also features a visual alarm light (LED1).
You can use a readymade or homemade water sensor (see below) with this circuit.
When connecting the water sensor probe to the sensor input port (WS) there is no need to observe the polarity. You can also use multiple water sensor probes (wired in parallel) in various locations around the area to be monitored.
After installation the water sensor probe should be tested with a wettish sponge or paper towel and inspected periodically. If there is any corrosion or damage the water sensor probe should be cleaned or replaced.
Now see my quick test setup of the high water sensor wired on a mini breadboard…
Nothing special, the output device connected during testing was a waterproof pink COB LED module (~150mA @ 9VDC).
So, the high water sensor provides a way to sense the presence of water. When water touches the sensor probe it turns on not only an onboard indicator but also an attached external annunciator.
The little circuitry uses a minimal number of low-cost, common parts (no microcontrollers) that can be assembled on a breadboard, perfboard, or a stamp-sized custom printed circuit board.
I hope you have been able to set up this circuit without any issues. If you do come across a problem, have feedback, I have missed something, or anything else you would like to say, then feel free to drop a comment below. See you next week!
