Low-Power Toilet Leak Detection System

An electronic water detection device comprising:

• a. a first MOSFET coupled to a 3.0-volt coin cell battery and configured as a high-side switch to control a first LED;
• b. a voltage monitoring circuit electrically connected to the gate of the first MOSFET and configured to activate the first LED when the supply voltage falls below approximately 2.7 volts;
• c. a second MOSFET electrically isolated from the first MOSFET and configured as a high-side switch to control a second LED;
• d. a moisture detection circuit comprising a pair of metal pins embedded in an absorbent wick and electrically connected to the gate of the second MOSFET, the moisture detection circuit being configured to activate the second LED when electrical resistance between the electrodes falls below approximately 2.2 Mohms;
• and,
• e. wherein the first and second MOSFETs operate independently to indicate low battery voltage and the presence of moisture, respectively.

A method for detecting the presence of moisture under a toilet using an electronic device, the method comprising:

• a. positioning a printed circuit board on the base of a toilet, the printed circuit board supporting a voltage monitoring circuit and a moisture detection circuit;
• b. coupling a first MOSFET to a power supply and configuring it as a high-side switch to control a first LED;
• c. electrically connecting the voltage monitoring circuit to the gate of the first MOSFET;
• d. activating the first LED when the supply voltage falls below a predefined threshold;
• e. positioning an adapter plate beneath the toilet;
• f. extending an absorbent wick upward from the adapter plate into fluid communication with moisture accumulating in the adapter plate;
• g. embedding a pair of electrodes within the wick and electrically connecting them to the gate of a second MOSFET, the second MOSFET and configured as a high-side switch to control a second LED;
• h. activating the second LED when electrical resistance between the pair of electrodes falls below a predefined threshold;
• and,
• i. wherein the first and second MOSFETs operate independently to indicate low battery voltage and the presence of moisture, respectively.