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:
Aug. 31, 1976
Filed:
Feb. 11, 1975
Applicant:
Inventor:
Petrie Johan van der Plaats, Hilversum, NL;
Assignee:
U.S. Philips Corporation, New York, NY (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04M / ;
U.S. Cl.
CPC ...
179 / ; 179 / ;
Abstract
A circuit arrangement for a tone push-button selection telephone subscriber set, in which a tone signal generator and a microphone amplifier are coupled to direct current networks, each of which is coupled to an output network such that two current mirror circuits having the same current ratio factor are obtained. The direct currents in the networks are exclusively switched by means of a long-tailed pair, so that the direct current flowing in the output network has a constant value.
van der Plaats, Petrie. (1976). Circuit arrangement for a tone pushbutton selection telephone subscriber (U.S. Patent No. 3978295). U.S. Patent and Trademark Office. https://idiyas.com/patent/badge/3978295
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile