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:
Oct. 25, 1983
Filed:
Oct. 01, 1980
Sai W Kwok, El Paso, TX (US);
GTE Products Corporation, Stamford, CT (US);
Abstract
A voltage comparator compares the DC current in active elements of a trunk amplifier with a variable reference voltage for detecting when to switch to a bypass mode. Its output is normally low for passing a current through it, an LED, and relay coils when the amplifier operates satisfactorily. Circuitry for establishing an allowable amount of decrease in DC current in a current sensing resistor R5, prior to switching the comparator for de-energizing the relay coils, comprises a first transistor Q4 that continuously conducts collector current through a load resistor, a second transistor Q2 that is only responsive to a low output voltage of the comparator for passing a prescribed current through the load resistor for decreasing the first transistor Q4 collector voltage a prescribed amount, and circuitry including voltage dividers for coupling a greater percentage of the change in Q4 collector voltage to the positive input of the comparator than to the negative input thereof which also senses the level of the DC current.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile