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:
Feb. 21, 1984
Filed:
Jul. 29, 1982
Jawed M Khan, Clearwater, FL (US);
GTE Business Communication Systems Inc., McLean, VA (US);
Abstract
Apparatus is adapted for connection to an alternating current source and a direct current power supply powered by the source. The supply is enabled when the source is operative and disabled when the source is inoperative. The apparatus utilizes first, second and third terminals. A power line monitor is connected at its input to said source and at its output to said first terminal. The monitor maintains the first terminal at a selected potential when the source is enabled, and is unable to maintain the first terminal at any potential when the source is disabled. A first circuit connected to the supply, a battery and the second terminal to charge said battery and to maintain the second terminal at a selected potential when the supply is enabled. The battery maintains the second terminal at the selected potential when the supply is disabled. The first circuit is connected via a resistor to the first terminal to maintain the first terminal at a different potential when the monitor is inoperative. An additional circuit is connected to the first circuit, the supply, the monitor and the third terminal to maintain the third terminal at a selected potential when the monitor is operative and to maintain the terminal at a different potential when the monitor is inoperative.