Password-Based Circuit Breaker for Secure and Authorized Control of Electrical Systems

Electrical safety is a major concern during the operation and maintenance of electrical systems, particularly when personnel work on energized circuits. Unauthorized or accidental operation of circuit breakers can result in electrical shocks, equipment damage, and unsafe working conditions. This paper presents an embedded password-based circuit breaker system designed to provide secure and controlled access to electrical circuits. The proposed system uses a PIC16F877A microcontroller as the central control unit, interfaced with a numeric keypad, LCD display, relay, buzzer, LED indicators, and regulated power supply. Before operating the circuit, the user is required to enter a predefined password through the keypad. The microcontroller compares the entered password with the stored password and operates the relay only when authentication is successful. Incorrect password entries are rejected and an audible indication is provided through the buzzer. A lockout mechanism after three consecutive incorrect attempts improves protection against repeated unauthorized access. The system also supports password modification through an authorized procedure and provides an administrator-password facility. The developed prototype offers a low-cost and practical approach for improving electrical safety and preventing unauthorized switching of electrical equipment.