INTERFACE DEVICE FOR CONNECTION OF USER COMMUNICATION LINE TO TELEPHONE EXCHANGE SYSTEM Russian patent published in 1997 - IPC
Abstract RU 2079208 C1
FIELD: communication devices. SUBSTANCE: device has first, second and third buffer units 1, 2, 8, first, second, third, fourth and fifth flip-flops 3, 4, 5, 6, 7, inverter 9 and OR gate 10. EFFECT: increased reliability of connection. 4 dwg, 1 tbl
