Master unlock circuit for an electronic telephone
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Aug 20, 1985
Grant Date -
N/A
app pub date -
Dec 12, 1983
filing date -
Dec 12, 1983
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
A circuit which unlocks the signaling circuit of a feature telephone station after it has been locked. A microprocessor disconnects a tone generator from an associated keypad upon detection of operation of a lock button. The microprocessor subsequently connects the tone generator to the keypad upon detection of operation of the lock button and a predetermined master unlock code provided via the keypad. The microprocessor also connects the tone generator to the keypad upon detection of operation of the lock button followed by simultaneous operation of a predetermined plurality of telephone feature buttons.
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