SUBSCRIBER TELEPHONE SET PROVIDED WITH PROTECTION DEVICES AGAINST OVERVOLTAGES

摘要

Subscriber telephone set with electronic control. The telephone set, protected upstream by two CTP resistances (3 and 4) and one VDR resistance (5) which are thermally coupled, is protected downstream of the hook (6) by a power limiter circuit (180) also acting as a line current switch through the transmission and numbering circuit (16) actuated from the digital keyboard (17). Application to electronic telephony.