Apex DIY Water on floor sensor

[schwaggs]

Introduction
This is my Water On Floor sensor circuit that I have been using on my system for over a year. The cicuit is very simple and the sensor is very sensitive. I will include specific instructions for the Apex but the basic hardware could be applied to any controller that supports switch inputs.

Supplies needed
1- Small 12V Relay (I used Magnecraft W107 available from All Electronics)
1 - Typical LED (optional indicator to tell when the sensor is wet)
1 - 470 ohm resistor (optional indicator to tell when the sensor is wet)
1 - GRI-2800 Water Sensor (~$16 on eBay)
1 - project box
1 - 12V power source
1 - Neptune Input Breakout Box (you can either buy this or make your own with a Mini DIN 8 cable)
Small pieces of wire for connecting components

Tools needed
Soldering iron
Solder
Wire cutter, etc

Assembly
Wire up the circuit as illustrated in the attached scematic. Install in project box. Connect to one of your Apex switch inputs.

Program
The program is quite simple:

[Outlet Water Alarm]
Set OFF
If Switchx10_6 CLOSED Then ON

Examples
This is a picture of my combination Water On Floor sensor and breakout box. Using a small project box from Radio Shack, a DIN 8 cable from eBay (cut in half) and some screw patch connectors (blue items in the picture) from Fry's....
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<legend> Attached files </legend>

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class="gc-images" title="box2.jpg[/IMG] style="max-width:300px" /></a>

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class="gc-images" title="Water Sensor Circuit.jpg[/IMG] style="max-width:300px" /></a> </fieldset>

 

[rbredding]

Great Writeup !!

Can the setup be modified to use several detectors? (to monitor water at each end of a 6' cabinet, for example)

Couldn't you just wire the water sensor directly to the Apex (by using an additional switch input "always on" to provide the power source)? (why do you need the separate power source) ?

[obviously, i don't know much about how these sensors work]

 

[schwaggs]

You might be able to wire 2 sensors in series using this circuit. I'm not sure it will work, never tried it. I have 2 separate circuits for my 2 sensors.

The Apex switch inputs do not provide power, this is why you need to use the circuit above. These sensors will work without the relay when connected to a typical home alarm system.

 

[rbredding]

They have to transmit SOME power, otherwise they wouldn't know when a float switch (or other switch) was closed.. (I just don't know how much current flows through a completed sensor circuit.. haven't tested it)

 

[schwaggs]

Let me rephrase that, the switch inputs do not provide nearly enough to power the water sensor circuit. I'm sure it is in the order of micoamps.

 

[schwaggs]

I don't see why not... you would have to use a 5V suppy (obviously ) and a different resistor on the LED.

 

[ichthyoid]

Schwaggs;667343 wrote: You might be able to wire 2 sensors in series using this circuit. I'm not sure it will work, never tried it. I have 2 separate circuits for my 2 sensors.

The Apex switch inputs do not provide power, this is why you need to use the circuit above. These sensors will work without the relay when connected to a typical home alarm system.

To use more than one of these sensors, on the same input to a controller, they should be wired in parallel. In parallel, either one would activate the alarm.

Otherwise, if you wired them in series, both sensors would need to be wet for the alarm to activate.

 

[shafiq_hossain]

Mullins,

What option did you go for at the end?

Thanks...