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. 24, 1977
Filed:
Jul. 06, 1976
George Verbaas, Brockville, CA;
GTE Automatic Electric (Canada) Limited, Brockville, CA;
Abstract
The disclosure relates to a balanced tone application system for applying dial tones, busy tones, or the like generated by a tone generator, to telephone transmission line pairs in a balanced manner and for use in a telephone exchange of the type having a supervisory relay coupled across an associated transmission line pair. The system comprises a transformer having a primary coupled to the tone generator and a secondary including first and second windings, a power source coupled to the first winding, a source of common potential coupled to the second winding, and a switching means coupled to the first winding, the second winding, the power source, the source of common potential, and to the supervisory relay. The switching means is switchable between first and second states for connecting the supervisory relay only to the power source and to the source of common potential when in the first state to thereby apply only energizing power to the supervisory relay and to the transmission line pair, and for connecting the supervisory relay to the power source, to the source of common potential, and to the first and second windings when in the second state to thereby apply both energizing power and the tone generated by the tone generator through the first and second windings to the supervisory relay and to the transmission line pair.