This paper presents the design and implementation of a motion sensor circuit, demonstrating the integration of digital logic components to create a responsive system. The circuit's operation is based on the principle of motion-induced infrared detection. The IR sensor emits infrared radiation, which, upon detecting motion, triggers the CD-4017 IC to advance its outputs, sequentially activating the Triac BT136 and illuminating an LED. The paper elaborates on the theory of operation, the practical procedures for building the circuit, the cost analysis, challenges, and precautions. The results of the experiment confirm the circuit's functionality, demonstrating reliable motion sensing and response. This project not only provides hands-on experience in digital logic circuits but also underscores the significance of meticulous component selection, careful assembly, and safety in electronics projects. Building this motion sensor circuit offers valuable insights into motion detection technology with practical applications in security and automation systems.