Easy Water Overflow Control Switch(No IC No MCU)




About: I am a Project Management Analyst at a reputed brand. Electronics and Photography are my hobby which I pursue on my weekends.


I wanted to build a simple circuit, no IC's no MCU's. So here what I have got.

What do I need

  1. Magnetic float switch.
  2. 12v Relay to handle 220v 30A.
  3. Buzzer 1.2-12V
  4. IN4001 or IN4007 Diode.
  5. 9V Battery

How do I make it

WARNING: This circuit involves 220V AC. Please use at your own risk.

  1. Install the float switch in water tank
  2. Connect the components as shown in circuit diagram
  3. Connect the Water pump motor to the relay.
  4. If required you can add a switch in case you need to power it Off/On

How it works

  • The circuit is power using 9V Battery.
  • A diode is used as a flyback to relay.
  • When the water level is low the float switch is in off state and this the relay, buzzer is off and thus the motor is off.
  • When water level reaches to full, the switch is on, this turns on the relay and buzzer. this turns off the motor.

Working design, i excluded the the relay, it only indicates when the tank is full.

Link of demo video:

Any questions feel free to ask.

Thanks for reading.



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