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:
Nov. 30, 1982
Filed:
Sep. 23, 1980
Richard H Peterson, Palos Park, IL (US);
James A Mornar, Crestwood, IL (US);
Other;
Abstract
An electronically controlled swell shutter operator for pipe organs includes an electric motor driving a speed reducer whose output is connected to move the shutters of a pipe organ swell chamber, in order to control the volume of sound heard by the listeners. A swell pedal controlled by the organ player operates a first potentiometer and establishes a first voltage of a given polarity, the magnitude of which represents the exact position that the shutters should be in. The output of the speed reducer operates a second potentiometer which establishes a second voltage of a polarity opposite to that of the swell pedal potentiometer, the magnitude of this second voltage being dependent on the position of the swell shutters. A system of integrated circuit comparators compares the above-mentioned first and second voltages to produce an error signal. A logic system responds to the comparison result to cause the shutters to move in a desired direction and at a suitable speed to reduce the error and to achieve a balance, whereby the swell shutters assume a position corresponding to the position of the swell pedal. Dynamic braking and a system of automatically adjustable dead bands prevents overshoot and hunting.