Tuning device for wind instruments - has electronic counter for setting to number corresp. to nominal frequency of tone

摘要

The tuning device consists of a circuit delivering the required instrument tone, a comparator, a display circuit for visual comparison of the two tones and a keyboard for the tome pitch adjustment and for octave switching over. The tome generating circuit converts thhe instrument tone into a rectangular oscillation, and has an oscillator whose fixed frequency is divided to obtain the tone nominal frequenncy. The latter is compared with the instrument tone and superposed on it. An electronic ccounter can be set to a number corresp. to the nominal frequency, and is automatically switched from backward to forward counting. L.e.d's are used as a display unit.