Hello All,

I am doing a project and I am responsible about safety for aquarium light system, I am supposed to have a moisture detector ( Could not find online) that detects if the prototype falls in the water of the aquarium. If it did, the sensor then sends a signals to open up the MAIN power supply which will result in shutting down the whole system including the moisture detector (since I am getting my power from the MAIN power supply) so I guess I will need my own power supply probably. For the circuit breakers, I have a “Latch Relay” dual coil switch (DSP1-L2-DC5V)that has a magnet where it will save the last state it had before tripping so the user can not reset the system by just plugging and unplugging the wire in the outlet. I will also have two mechanical push buttons, one normally open and one normally closed to be able to reset the system manually. I also need Remote Control Circuit Breaker (RCCB), I have searched for RCCB for over a week now and could not find one that has current rating between 60 mA to 250 mA. They all operate with current ratings from 5A to 100A which is away from ideal for my project.


Please, I need help in finding:


1) 1) Moisture Detector
2) 2) Remote Control Circuit Breaker: Current Rating between 60mA and 250 mA


Thank you

 

You will likely be dead by the time your moisture sensor detects water and has shut down your circuit.
Typically a device like this is protected by a GFCI outlet.

Is this a project for school or something you intent to sell or what?

 

Thanks for replaying mcgyvr,

It is a project for school and I will use a moisture detector not a moisture sensor because the sensor needs couple seconds to respond where as the detector I am looking for comes in a package with the comparator implemented inside. My professor told me it is out there in the market but when I search for moisture detector I could not find any.

 

Simply Google.. "water leak detector schematic" there are hundreds of schematics to trigger a relay,etc... when the presence of water is detected.

No need for a remote circuit breaker either. You simply use a relay to open the main power circuit when the sensor detects water..

But again this isn't a practical real world solution to the problem like a GFCI outlet is. So please don't actually try it with your arm sticking in the fish tank.. you will be "shocked" to find out how bad of an idea this really is. You are just learning to detect water and respond to it

 

Nice, but do you know some GFCI's with a kind of memory to save the last state it was in before it tripped.

Bottom line, I need some kind of memory to keep track of the last state even after the disconnection of the power so it could save the last state

 

I can add some clarification about the project since its also mine (Im working on a seperate part). I referred abuyaser to this site.

From one aspect, the parameters of this design are from the professor. There are some things about it that dont make sense. The aquarium light all LED, with an external PS that converts AC to 24VDC, so that only 24VDC is even exposed to the water should the unit fall into the water in the first place. 28V is what the US-Navy considers the maximum "touch voltage" where any higher could cause a person a shock in direct contact conditions (touching the conductor). Since we are 24V across multiple channels and direct 'touch' is not really possible, even a GFCI is overkill. The production version was also intended to be waterproof as well, so yeah... its waaaaay overkill. But hey, the professor wants what the professor wants.

As for the prototype's water sensor, I figured we could get one of these and cut off the conductivity/TDS probes:
http://www.amazon.com/HM-Digital-DL...AZGW/ref=sr_1_8?ie=UTF8&qid=1303429579&sr=8-8