When feedback is used in electronic circuits, it is usually of a negative nature; positive feedback can be difficult to control, damage circuitry, and has limited uses. However, while positive feedback is often avoided, it can be exploited for specific needs. This project was an attempt to use and control positive feedback for the purpose of creating a self-oscillating device capable of exciting and sustaining the strings of an electric guitar. The device operates over a range of 80 to 1 kHz, uses a 9V battery for power, and incorporates several modules into the body of an electric guitar. This project looked at several approaches to the basic Wien-Bridge oscillator, in an attempt to replicate the functionality of the only product currently on the market; the EBow™. LTSpice™ software was for the simulation of circuitry, while an oscilloscope was used to observe circuit behavior. Due to the failure to replicate the functionality of an EBow, this project is a case study into positive feedback, self-oscillation, and the device itself.
