High voltage detection circuit, bell signal detection circuit an
Hold and dial accessory for telephone instrument
Hybrid alphanumeric telephone directory
Hybrid circuit for an electric operating and scanning interface,
Illuminated button backlighted by white light
Impact activated telephone method and apparatus
Independent hysteresis apparatus for tone detection
Index device for automatic information retrieval
Information entry device
Information signal detection device and information signal detec
Information storage device for storing personal identification i
Information storage system
Information terminal capable of originating a call, method...
Input method using standard numeric keypad
Integrated circuit amplifier and method of adaptive offset
Integrated circuit for generating a melody and ring
Integrated keypad system
Integrated ringer for short telephone lines
Integrated ringer for short telephone lines
Integrated ringer for short telephone lines