Executive Summary of the Automatic Instrument Tuner
A guitar tuner includes a manually graspable body with a head projecting outwardly from one end driven by a motor inside the body to rotate about an axis. The head includes a slot shaped opening for grasping the key of a conventional instrument such as a guitar. An input sensor in the body detects a tone from the string of the instrument and converts it to square wave of the detected frequency. This is compared by a microprocessor with the closest adjacent intended frequency of the instrument selected which acts to drive the motor to tighten or loosen the string as required to attain the required frequency. A digital display provides a readout of the number and letter of the string concerned. The user can select any one of a number of different states of the device for use with different instruments or different tunings. The user can also override the automatic string selection in cases where the string is a long way from its required frequency.