Battery feed circuit
Battery feed circuit for a pair of subscriber lines
Battery feed circuit for a telephone system
Battery feed circuit for supplying feed current to telephone set
Battery feed for telephone line cards
Battery switching in a telephone subscriber line interface circu
Battery-feed circuit for exchange
Bidirectional adaptive voice frequency repeater
Bipolar pulse forming line
Call eavesdropping arrangement
Call processing using previously obtained line characteristics
Canceller trained echo suppressor
Circuit arrangement for generating charge pulses
Circuit arrangement for providing power for an IC chip in a tele
Circuit compensating for the attenuation of a notch filter at fr
Circuit for monitoring battery voltages of telephone terminal fa
Circuit for remote supply of subscriber line terminals in a tele
Circuit for telephone set comprising a light-emitting diode powe
Combination exterior telephone service terminal and splicing...
Communication system with active noise cancellation