Telephone line bridging sensor
Telephone line coupler
Telephone line coupler
Telephone line coupler
Telephone line interface circuit
Telephone line loop current regulator
Telephone loop current modulator
Telephone ring signal detector
Telephone set with on-hook line seizure
Telephone subscriber circuit with galvanic isolation
Telephone subscriber line voltage change detection
Telephone subscribers' circuits
Telephone system
Telephone terminal apparatus and method
Telephone terminal device with means for detecting abandonment o
Telephone terminal equipment interface circuit
Telephone trunk interface circuit
Telephony distribution system
Test method for line equipment including a hybrid circuit...
Three relay C. O. trunk interface