Paystation transmitter ground detect circuitry
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United States of America Patent
Stats
-
Apr 11, 1989
Grant Date -
N/A
app pub date -
Jul 1, 1988
filing date -
Jul 1, 1988
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
A ground detect circuit for use in telephone paystation consisting of a comparator circuit which compares the voltage across a telephone transmitter included in the paystation to prevent users from fraudulent use of the instrument by grounding the handset transmitter to signal the central office that initial rate deposit has been made when in fact it has not. The ground detect circuit upon detecting the presence of ground at the transmitter generates a signal which can be utilized to disable an associated calling device.
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Family
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Cited Art Landscape
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