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:
May. 16, 1989
Filed:
May. 16, 1988
Applicant:
Inventor:
Gary Grantland, Hartselle, AL (US);
Assignee:
Palco Telecom, Inc., Nashville, TN (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04M / ;
U.S. Cl.
CPC ...
379143 ; 379395 ; 379145 ;
Abstract
A paystation telephone level control system is disclosed including a telephone receiver driven by a local amplifier and wherein two sets of attenuating resistors, a coarse attenuation set and a fine attenuation set, interface with connectable terminals of a binary control crosspoint switch. The presence or absence of coin tones and dialing tones are detected and the crosspoint switch discretely controlled by their presence to effect discrete levels of attenuation of signals fed to the receiver. In addition, the lever of attenuation during voice communications is a function of a pre-adjusted attenuation and a user selection.