Abstract
A First-year Soldering and Analog Music to Light Modulator Electronics Lab ProjectThis paper describes an introductory electronics lab project which has been iteratively improvedover three years in an introduction to engineering course. This one credit course consists of asingle 100 minute lecture and lab each week during a 14 week semester and thus requires eachactivity to be as time efficient as possible. The project was implemented in a course that consistsof both electrical and mechanical engineering students at an urban, private institution in theMidwest.For this hands-on project students learn about analog electronic components and soldering whilebuilding a circuit which can be used to make lights turn off and on with a music signal. Thecircuit can be connected to many music sources using an auxiliary cable and incorporatesresistors, a potentiometer, an infra-red LED, an opto-triac, and a triac, as well as variousconnectors. Students spend two lab periods soldering their circuit together, making themechanical connections to mount it in a clear plastic box and testing its performance and areallowed to keep their project when complete. During operation, when the music signal hits athreshold voltage Christmas lights will turn on. A successfully built circuit excites threephysiologic senses (sight, hearing and touch) in that the base signal in music typicallycorresponds to the highest voltage which can trigger the lights. A user can hear and feel the basesignal and see the lights turn on correspondingly. By analyzing a music signal during lecture,and how the various components affect this signal, students gain a practical understanding of theelectronics and how they are integrated to create the circuit’s functionality.Surveys of 147 students used at the start of the semester have shown that only 37% of thestudents have prior experience with soldering or circuits. Of this 37%, only half still ratethemselves as confident in their soldering ability at the start of class. An end of class survey andexam questions specific to this project are used to assess the quality of the project, its deliveryand student learning. Results show that after completing this project 92% of students areconfident in their ability to solder without supervision and 93% of students use the circuit theybuild for this project outside of class. The overall rating for the project is a 4.8/5 using a Likertscale making it the highest rated project ever implemented in this class. This paper describes thecircuit, lab exercise, in-class curriculum and assessment of this project and provides a detailedbill of materials. Alterations to the current circuit which would provide a deeper experience withcircuits and electronic components, such as amplifiers and RC filters, are also discussed anddemonstrate the potential for this project to be applied in a variety of courses.