Low power emergency telephone mode
AssigneeAdvanced Micro Devices, Inc.
InventorsJoseph W. Peterson, Dale E. Gulick
Life of this patent
Estimating the term…
Abstract
A cordless telephone that may be fully powered by AC main power lines and only partially powered by telephone lines includes structure for producing dual tones, structure for producing dual-tone multifrequency tones from the dual tones, and structure for empowering each of the foregoing in the event of AC main power failure where the only power available passes through the telephone lines.
Claims11
In a cordless telephone of the type that is directly connected for operation to a public switched telephone network line and also to an AC main line, and of the type that also has a hookswitch and a dialer, both of which are controlled by a microcontroller, a method for selectively enabling telephone functions in the event of an AC main line power failure, said method comprising the steps of:
- obtaining power from said public switched telephone network line;
- enabling said hookswitch with said power obtained from said public switched telephone network line;
- and
- enabling said dialer with said power obtained from said public switched telephone network line.
A cordless telephone of the type that is directly connected for operation to a public switched telephone network line, that may be fully powered by AC main power lines and that may be only partially powered by telephone lines, said cordless telephone comprising:
- means for producing dual tones;
- means for producing dual-tone multi frequency tones from said dual tones;
- means for outputting said dual-tone multi frequency tones;
- and
- means for empowering said means for producing dual tones, said means for producing dual-tone multi frequency tones and said means for outputting in the event of AC main power failure, where the only power available passes through the telephone lines.
A cordless telephone of the type that is directly connected for operation to a public switched telephone network line and, further, that is capable of performing, when enabled, functions related to dialing and functions not related to dialing, said apparatus susceptible to having to operate during periods in which the amount of power available is insufficient to sustain full operation, said apparatus comprising:
- a digital signal processing engine that may perform dual-tone multifrequency functions;
- and
- means for slowing the rate of operation of said digital signal processing engine during periods in which the amount of power available is insufficient to sustain full operation.
Dependencies are inferred from the claim text.