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
Ringer for satellite user terminals
Ringer unit driving system in a subscriber transmission system
Ringing application circuit
Ringing detection circuit
Ringing scheduling for FXS ports on platforms with limited...
Ringing signal reformatting circuit
Ringing tone apparatus
Ringing tone signal detecting circuit
Ringing-tone control device for telephone set, using audio...
Selective ringing receiving device and method
Selective telephone ringing-signal interruption
Sensor circuit for a telephone line
Signal analyzing system