INTERFACE SYSTEM BETWEEN MICROPROCESSOR HARDWARE AND TWO-WIRE TELEPHONE-LINE ANALOG SUBSCRIBERS (ALTERNATIVES) AND INTERFACE MODULE FOR THESE SYSTEMS Russian patent published in 2001 - IPC

FIELD: computer and communications engineering; multichannel boards built in computer for its interfacing with several telephone lines. SUBSTANCE: one of system alternatives has at least two modules, analog-to-digital converter whose input is coupled with multiplexer output, peripheral computer whose input is coupled with analog-to-digital converter output and whose output is connected through interface to peripheral devices. Each module incorporates differential amplifier built around operational amplifier and resistors. EFFECT: improved performance characteristics due to easy connection of new lines. 11 cl, 7 dwg