The creator of the project was inspired by a leaking filter of an aquarium and a blocked drain of a combination boiler which could have been prevented if there was as early alarm.
Although water leaks are hard to be prevented, there is a possibility to discover them at an earlier time. A sensor can be created using two short wires with stripped off insulation. With the ends of the sensor wires, the circuit is sensitive enough to sense a drop of tap water. To prevent the noise from being picked up, the sensor can be connected to the circuit with twisted pairs. Along with the sensor is a buzzer that will produce sound upon the detection of water.
The circuit needs low power consumption if it has to run on batteries. To do this, the gate of a MOSFET is made as the input of our circuit. Also, the buzzer is intermittently turned ON when water is detected, to minimize the power consumption. This is done by activating the buzzer for about 1 to 1.5 seconds every 10 seconds. An astable multivibrator with two transistors is chosen to implement the discrete parts for the oscillator.
The buzzer is not paralleled with a capacitor which prevented the operation of the oscillator since it can make the buzzer to remain ON. The built-in oscillator can generate the bleeping noise for most active buzzers. The battery should be mounted separately to prevent leakage.
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