Dell 1815 Mono Laser Service Manual page 23

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
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
Ring detection Frequency : 15.3Hz
Ring detection Current : 20mA
3) False Ring Sound
Ring Frequency : 750 Hz + 1020 Hz
Ring interrupt Cycle : On/Off depending on input Ring Signal Cycle.
50mm
150Vrms (condition :Current=25mA,Frequency=15Hz)
product Margin : 30Vrms
68Hz (condition : Voltage=45Vrms,Current=25mA )
product Margin : 15Hz
100mA (condition : Voltage=40Vrms,Frequency=20Hz)
product Margin : over 15mA
150Vrms
70Hz
System Outline
Service Manual
4-5