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:
Apr. 18, 1978
Filed:
Aug. 02, 1976
Robert M Thomas, Maitland, CA;
John A Gauthier, Brockville, CA;
GTE Automatic Electric (Canada) Ltd., Brockville, CA;
Abstract
A control point driver circuit for use in a telephone exchange for energizing and deenergizing a control element such as a control relay in response to set and reset input pulses. The control point driver circuit comprises a transformer having a centertapped primary forming set, reset, and common inputs for receiving the set and reset input pulses and a secondary coupled to a constant control voltage. The control point driver circuit also includes a comparator having a first input coupled to the transformer secondary, an output coupled to the control relay to be energized and de-energized and a second input coupled to the comparator output for receiving first and second reference voltages which are related in magnitude to the constant control voltage to maintain the comparator in the set state or reset state indefinitely until a reset or set input pulse is received. A received input pulse causes an induced voltage within the transformer secondary which augments the control voltage to change the relation in magnitude between the reference voltages and the control voltage to cause the comparator to change states in response to the received set and reset input pulses. When the comparator is in the set state, the control relay is energized and when the comparator is in the reset state, the control relay is de-energized.