Remote telephone ringer controller
Remote telephone signaling circuitry and device
Ring code recorder
Ring control device
Ring detector
Ring discriminator
Ring filter for pots communication system
Ring generator
Ring tone detection for a telephone system
Ring tone visualizer
Ring trip circuit having a simple trip detecting circuit of a hi
Ring varying technique for a telephone
Ring-tone identification of urgent phone calls
Ring-tone identification of urgent phone calls
Ring-tone muting device and processing method
Ringer assembly
Ringer circuit
Ringer circuit
Ringer circuit for generating sine wave
Ringer circuit, particularly for a telephone set