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:
Jul. 21, 1992
Filed:
Feb. 15, 1991
Eugene D Kelley, Sarasota, FL (US);
Charles E Murphy, Sarasota, FL (US);
Piera G Kelley, Sarasota, FL (US);
Donald J Munn, Bradenton, FL (US);
Elcotel, Inc., Sarasota, FL (US);
Abstract
A line powered telephoe is disclosed in which the telephone is not powered from a separate external source. The improved pay telephone is powered solely by loop current available on the telephone line from the central office. A rechargeable battery is provided to store excess loop current to enable operation of the pay telephone when not off-hook to the central office. Power consumption by components of the telephone is minimized by shutting down unnecessary functions on a selective basis to ensure that sufficient excess loop current is available to recharge the battery. In addition, an improved switched-capacitor circuit is disclosed to enable storage of electricity at a voltage potential higher than the off-hook line voltage to enable firing of standard high voltage relays for coin collection and coin return.