SteveQ
Active Member
Xap 1-Wire water leak detector
There have been sa few posts lately regarding the need for an inexpensive sensor to detect water leaks.
So if you have a 1-wire network here is a simple but very effective water sensor based on a DS2405 switch. The 1 -wire circuit will need +5V available.
A simple paper sensor is attached to a 1-wire switch. When the paper gets wet it triggers the switch. The circuit shown in the attached diagram consists of a piece of paper that has been impregnated with a salt solution and dried . When The paper gets wet, the salt water completes the circuit and triggers the DS2405 switch.
The water sensor consists of a pair of copper wires (stripped 1.5") in direct contact with a piece of filter paper (any absorbent paper 1/16 to 1/8 inch thick will work) see photo 1.
To make the paper,Prepare a salt water solution by dissolving 1 teaspoon of table salt in 4oz of water.
Saturate a 3" x 3" square of filter paper with the salt solution. Allow the saturated paper to dry overnight, or you can speed up the process with a hair dryer or your microwave oven. Be sure the paper is thoroughly dry. Cut the 3" square into 4 smaller squares. You will use 1 of the smaller squares for each sensor.
To finish the sensor; place the stripped pair of wires on the floor in the area where water is first likely to appear (low spot if possible). Put the dry filter paper on top of the wires and use duct tape to tape the paper to the floor. Be sure to leave at least one edge of the paper slightly exposed so that it can absorb any water that gets on the floor (see photo 2). Connect the other ends of the wires to the DS2405 switch circuit as indicated in the circuit diagram. That's it - Done!
When water touches the filter paper it is quickly absorbed and will trigger the DS2405 switch circuit in a matter of seconds.
Disclaimer: Prolonged exposure to high humidity may cause the sensor to collect enough water to trigger the sensor. The copper wires in contact with the salt will eventually corrode to the extent that they could become non-conductive.
Steve Q
There have been sa few posts lately regarding the need for an inexpensive sensor to detect water leaks.
So if you have a 1-wire network here is a simple but very effective water sensor based on a DS2405 switch. The 1 -wire circuit will need +5V available.
A simple paper sensor is attached to a 1-wire switch. When the paper gets wet it triggers the switch. The circuit shown in the attached diagram consists of a piece of paper that has been impregnated with a salt solution and dried . When The paper gets wet, the salt water completes the circuit and triggers the DS2405 switch.
The water sensor consists of a pair of copper wires (stripped 1.5") in direct contact with a piece of filter paper (any absorbent paper 1/16 to 1/8 inch thick will work) see photo 1.
To make the paper,Prepare a salt water solution by dissolving 1 teaspoon of table salt in 4oz of water.
Saturate a 3" x 3" square of filter paper with the salt solution. Allow the saturated paper to dry overnight, or you can speed up the process with a hair dryer or your microwave oven. Be sure the paper is thoroughly dry. Cut the 3" square into 4 smaller squares. You will use 1 of the smaller squares for each sensor.
To finish the sensor; place the stripped pair of wires on the floor in the area where water is first likely to appear (low spot if possible). Put the dry filter paper on top of the wires and use duct tape to tape the paper to the floor. Be sure to leave at least one edge of the paper slightly exposed so that it can absorb any water that gets on the floor (see photo 2). Connect the other ends of the wires to the DS2405 switch circuit as indicated in the circuit diagram. That's it - Done!
When water touches the filter paper it is quickly absorbed and will trigger the DS2405 switch circuit in a matter of seconds.
Disclaimer: Prolonged exposure to high humidity may cause the sensor to collect enough water to trigger the sensor. The copper wires in contact with the salt will eventually corrode to the extent that they could become non-conductive.
Steve Q
