Dell 1815DN service manual Line Interface Part, Ring Sensitivity

System Outline

4.1.3 Line Interface Part

This is Connection Part between system and PSTN(Public Switched Telephone Network), and primary circuit is usually located. Main functions are Line Interface, Telephone Connection and Line Condition Monitoring.

1 Telephone Line Connection

Modular Plug : RJ-11C

LIU PBA Modular Type : 623 PCB4-4

Line Code Length : 2500 50mm

Line Code Color : Black

ON HOOK state Characteristic 1) DC Resistance

DP Dial Mode (Direct Current 30mA) : 50 ~ 300ohm DTMF Dial Mode (Direct Current 20mA) : 50 ~ 540ohm

2) Ring Sensitivity

Ring detection Voltage : 40Vrms 150Vrms (condition :Current=25mA,Frequency=15Hz) product Margin : 30Vrms 150Vrms

Ring detection Frequency : 15.3Hz 68Hz (condition : Voltage=45Vrms,Current=25mA ) product Margin : 15Hz 70Hz

Ring detection Current : 20mA 100mA (condition : Voltage=40Vrms,Frequency=20Hz) product Margin : over 15mA

3) False Ring Sound

Ring Frequency : 750 Hz + 1020 Hz

Ring interrupt Cycle : On/Off depending on input Ring Signal Cycle.

Service Manual 4-5