dilshan/electronic-limit-switch

Electronic Limit Switch

This is an open-source fluid level control module designed for reliable and automated liquid management in tanks.

Overview

This module can utilize two float-type limit switches or electronic sensor switches to detect fluid levels and control a relay accordingly. A microcontroller implements hysteresis logic to avoid unnecessary relay toggling caused by minor fluid level fluctuations, which enhances the system's reliability and lifespan.

How it works

1. The module monitors two limit switches:

   • Upper limit switch (J1): Closes when the fluid level falls below the upper threshold.
   • Lower limit switch (J2): Closes when the fluid level rises above the lower threshold.

2. Based on these inputs, the onboard microcontroller:

   • Activates or deactivates the relay.
   • Applies hysteresis logic to prevent rapid toggling.

3. The J4 terminal block provides:

   • AC mains input (up to 240V).
   • Relay output for controlling pumps or other devices.

License

This is a certified open-source hardware project. All design files, documentation, and firmware source code are available for download at the project source repository. The content of this project is distributed under the following licenses:

• Hardware license: CERN-OHL-W
• Software license: MIT License
• Documentation license: CC BY 4.0