COIN TELEPHONE ANTIFRAUD CIRCUIT
United States Patent 3428751
US Patent References:
Coin identification and signalling telephone device
- - 3069502


Inventors:
Edington, John E.
Publication Date:
02/18/1969
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Assignee:
BELL TELEPHONE LABOR INC
Primary Class:
379/145
International Classes:
H04M17/02; H04M17/00; H04M17/02




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