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:
Feb. 09, 1988
Filed:
Sep. 02, 1986
W David Pace, Tempe, AZ (US);
Dennis L Welty, Mesa, AZ (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A speakerphone circuit having fast sensitive switching between the receive mode and the transmit mode is disclosed which includes circuitry for providing four point sensing at the input and output of both the transmit and receive attenuators located in the transmit and receive signal paths thereof for controlling the gains of the attenuators in a complementary manner. A logic control circuit comprising a controller circuit provides an attenuator algorithm that first detects that voice signals are present in both signal paths then quickly causes the attenuators to be set to equal gains during a fast idle mode to then allow the stronger of the two signals to set the operating mode of the speakerphone.