Water tank overflow liquid level sensor alarm circuit

Posted on Feb 6, 2014

Water tank overflow liquid level sensor alarm circuit is a simple electronics project for school students. In the previous articles we had discussed about numeric water level indicator and water level controller circuit, but those circuits are much complex and areadvanced projects for engineering students. The circuit schematic for water tank over

Water tank overflow liquid level sensor alarm circuit
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flow alarm is shown below. It produces a beep sound when the water tank is completely filled by water. The advantage of this projectcircuitis that it saves water fromaccidental over flow. The circuit simply consists of a liquid (water) level sensor or water level detector with BC547 transistors. Any electronics hobbyist can implement this circuit at your home or work places at a cheap rate ($0. 5). The heart of this water over flow circuit is the transistor switching part. So this circuit always prevents the wastage of water when you forget to switch OFF the motor pump set after switch ON. Initially the potential at point A in the circuit is Vcc, so the transistor Q1 remains in ON state (Read transistor act as a digital switch ) and its collector voltage at Vce sat (0. 02V). A connection from ground is dipped in the water reservoir. When water level rises, the ground comes in contact with the base terminal of transistor Q1. Thus it changes to OFF state and the collector voltage rises to Vcc. The high voltage at the collector of Q1 turns ON the transistor Q2 since this high voltage is connected to the base of transistor Q2, then a current flow occur though the buzzer circuit and it produces beep alarm sound. (Read transistor act as a load switch ) If you are interested in similar project circuits don`t forget tolike our facebook page and also subscribe via mail. Feel free to use the comment box below to clarify your doubts.

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