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. 21, 1989
Filed:
Feb. 23, 1988
Fred D Waldhauer, La Honda, CA (US);
Resound Corporation, Redwood City, CA (US);
Abstract
A programmable low voltage compressor circuit suitable for use with hearing aids is described. The compressor has a continuously variable compression ratio wherein the gain of the compressor may be programmably controlled over a wide range and the compressor may be powered from a power source as low as 1.1 volt. The compressor employs a variolosser wherein the gain is controlled by the ratio of the currents flowing out of first and second control terminals. A control circuit coupled to the variolosser controls the magnitude of the currents flowing out of the two control terminals. The control circuit includes a peak detector which generates a signal related to the peak positive envelope of the signal input to the compressor. A voltage to current converter is coupled to the peak detector for increasing the magnitude of the current flowing out of one of the control terminals of the variolosser as the voltage output of the peak detector increases. Furthermore, the gain and compression ratio of the compressor over a wide range is programmably controllable.