Power and signal transmission system
Power cross detection using loop current and voltage
Power up reset circuit for line powered circuit
Primary telephone line protector with failsafe
Protection arrangement for a telephone subscriber line interface
Protection circuit for telephone systems
Protection circuit for use with a telephone appliance and method
Protection circuit/method for subscriber telephone interface...
Protection device for terminal equipment on telephone subscriber
Protection of active telephone line interface circuits
Protective plug for distribution frame devices in...
Protector device
Protector interface
Protector module for quick clip terminal telephone connector blo