E.I. Ibhadode

Motion detection is now crucial for modern security frameworks and energy conservation efforts, offering superior protection and mitigating energy waste from appliances left running. This project addresses the need for a reliable, economical, and highly effective sensor system by focusing on the design, construction, and testing of a Passive Infrared (PIR) Motion Sensor prototype. The primary goal is to create a robust device capable of identifying movement across a complete three hundred and sixty degree field of view, enhancing its utility over standard directional sensors and providing a valuable contribution to localized security solutions. The technical implementation began with a robust Power Supply Unit built from scratch. This unit uses a step down transformer, a full wave bridge rectifier, and a large smoothing capacitor to transform high voltage AC into smooth DC. An LM7805 voltage regulator guarantees the stable five volt supply essential for the sensitive electronic components. The Sensing Circuit uses a PIR sensor and a Fresnel lens to detect infrared energy. The weak analog signal generated by moving heat sources is processed by an operational amplifier and a comparator to create a clear digital trigger. This trigger then activates a transistor to energize an electromagnetic relay and a buzzer, which serve as the system's immediate response mechanism. Testing confirmed that the prototype successfully met all objectives. This included the reliable detection of motion within the predetermined area, the empirical definition and adjustment of the effective detection range, and the successful fine tuning of system sensitivity. Furthermore, the strategic design achieved the critical goal of wide coverage. This project validates the construction of a low cost, energy efficient device, affirming the practical application of knowledge in electronics design, power management, and embedded systems, and establishing a successful framework for automated lighting and intruder alarm systems

Induction motors, though robust, are prone to electrical and thermal stresses that can cause costly failures, while traditional protection devices are either too slow, prone to nuisance trips, or too expensive for small industries. The problem therefore lies in
the lack of an affordable, reliable, and adaptable protection system that integrates both electrical and thermal monitoring. The aim of the project is to design a micro- controller-based protection system for three-phase induction motors to detect faults
such as single-phasing, under voltage, and overheating. A functional protection system was built using the PIC16F877A micro-controller to achieve real-time monitoring and automatic motor isolation. The design employed ZMPT101B voltage sensors, an ACS712 current sensor, a DS18B20 temperature sensor, LM7805 regulator, ULN2003 driver, relay/contractor, and a 16×2 LCD. The
methodology involved circuit design and simulation, hardware assembly, and programming in Embedded C to process sensor data, and control the relay for fault response for phase failure or for temperature above 60 degrees. The performance of the system was rigorously evaluated through testing in both faulty and normal operating conditions. During fault simulation, the system
accurately identified phase loss, displaying "Phase Failure" on the LCD followed by the specific faulty phase voltages. When the motor temperature exceeded 60°C, the display indicated "Over Temp" and subsequently showed the actual real-time temperature measurement. Conversely, once the faults were cleared and the system was restored to normal operation (with phases at 220V and temperature below 60°C), the LCD confirmed that the Relay was switched ON, reconnecting the motor to the power source. Following this restoration, the system resumed its standard monitoring mode, displaying the actual temperature and operational parameters, thereby proving the system’s reliability in managing transitions between fault detection and safe recovery.