Dell 1600n - Multifunction Laser Printer B/W Service Manual page 156

Circuit Diagram
This is Connection Part between system and PSTN(Public Switched Telephone Network), and 1 st side 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 : 2m
• Line Code Color : Ivory
11.2.1.4 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)
• Ring detection Frequency : 15.3Hz % 68Hz (condition : Voltage=45Vrms,Current=25mA )
• Ring detection Current : 20mA % 100mA (condition : Voltage=40Vrms,Frequency=20Hz)
3) False Ring Sound
• Ring Frequency : 750Hz + 1020Hz
• Ring interrupt Cycle : On/Off depending on input Ring Signal Cycle.
Service Manual
11-8
product Margin : 30Vrms % 150Vrms
product Margin : 15Hz % 70Hz
product Margin : over 15mA