2025-03-06http://itsupport.cu.edu.ng:4000/handle/123456789/28882This paper reports the design and construction of a security system. The system will produce sound of a barking dog at audible frequency of 9 KHz. The design procedure and principle of operation of the various modules as presented in this work are based on the locally available electronic componentsapplication/pdfQC PhysicsArticle