Water level indicator- Water alarm- DIY Water switch

Make your DIY water spill detector/water switch/water level indicator using transistors.

This is a simple project that uses NPN transistors to switch on the indicator LEDs and hence revealing the water level/water spill over the surface.

FEATURES-

1. Water spill indication
2. Water Based Switch
3. Water level indicator

Components Required-

1. BC547 Transistor - 4
2. Resistors - 220ohm - 4 and 1K ohm - 4
3. LEDs - 4
4. Battery (5-9V) - 1
5. Connection wires

Working -

In this project, we are using a transistor(NPN) as a switch. Initially, there is no voltage applied at the base of the transistor, therefore the transistor is in OFF state and no current flows through the collector and emitter junction. But when the water touches the transistor base contact wire, the current flows through the base of the transistor which turns switch ON and current flows through the LEDs.

Circuit schematics-

Here we are using 4 LEDs to indicate the water level -

Note- You can also add a buzzer as an alarm in the above circuit instead of LEDs

The 4 transistors are working as a switch that is triggered by the current through the base of the transistor used. When the water level reaches to the contact wires a small current flow through the base which turns ON the switch and hence the LED is turned on.

The 4 transistor triggers 4 different switches to indicate the water level.

This circuit can be modified into a water spill detector by connecting a buzzer/LED to the load and using a single transistor based switch.

 Buy resistors pack from here.