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:
Mar. 04, 1997
Filed:
May. 31, 1994
Graham A Laidler, Ipswich, GB;
British Telecommunications public limited company, London, GB;
Abstract
Apparatus powered from a communications line minimizes current drawn from the line by use of a variable power supply having a DC to DC conversion circuit controlled by an oscillator. The output of the DC to DC conversion circuit in a first lower power drawing mode is used to power a tone detection circuit which monitors the line for a wake-up tone. On receipt of an appropriate wake-up tone, the tone detection circuit provides an interrupt signal to a microprocessor which, in response, causes an increase in the oscillator frequency. The increased oscillator frequency then increases power drawn from the line via the DC to DC conversion circuit for operation in a second higher power drawing mode.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile