The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 29, 1977
Filed:
May. 22, 1975
Albert E Sanderson, Carlisle, MA (US);
Inventronics, Inc., Carlisle, MA (US);
Abstract
A musical tuning aid. The tuning aid generates a digital note signal at the frequency of a selected partial of a note being sounded and combines this note signal and a four-phase digital clock output having a reference frequency to produce four output signals which low-pass filters convert to dc output signals. Each output signal indicates the instantaneous phase difference between the note and a respective one of the clocking signals. Each dc output output signal controls the light from a pair of lamps. Individual lamps in each pair are diametrically opposed on a circle with all the pairs being equiangularly spaced. The lamp pairs reach maximum brightness in sequence, providing the illusion of a rotating light bar. The direction of rotation indicates whether the note being tuned is flat or sharp and the speed of rotation is proportional to the frequency deviation from the reference.