Samsung SCX-5312F Service Manual

Also see for Office Master SCX-5312F: Manual Driver manual Driver guide Product guide Manual Del Usuario

Contents

3-34CIRCUIT DESCRIPTIONSamsung ElectronicsRepair Manual3-7 LIU PBA3-7-1. SUMMARYLIU WIRE CONNECTS Main B’D’s MODEM AND LINE PARTS, AND IMPEDANCE MATCHING (AC, DC), RING DETEC-TION PART and LINE SEIZURE (DIALER).3-7-2. DC MATCHING PARTNormal movement range of LIU is 12mA ~ 9mA.Adapting CTR21 standard, the regulation limits to 60mA CURRENT flow through the terminal.Therefore, select (*:for EU PIT) Option to connect necessary items then the current through LIU will not exceed 60mA.• CTR21 Standard(Europe) : 12mA~60mA • OTHER Standard (U.S.) : 12mA~90mADC has a character to pass through the LINE. And with Q1 (VN2410) GATE section’s LINE INPUT corrent and Q1 Sourceconnection to R20, can be decided as follows :• -VDCR = VL1 + ILINE X R20(VDCR : Tip-Ring CD Voltage, ILINE : Current flow)VL1:Line Input Voltage, VL1=VBD1+VCE(Q2)+VDS(Q1)3-7-3. AC MATCHING PARTBasic LIU’s AC IMPEDANCE is 600 and uses R47. 48. C36 to possibly control combined IMPEDANCE.• U.S. Usage : A terminal IMPEDANCE Æ 600W(±30%)• CTR21 : A Terminal IMPEDANCE Æ 270+750W//150nF3-7-4. DIALER PART*MF DIALDTMF Dialing is controlled by MODEM and should be selected by appropriate LEVEL and On-off Time output based on eachcountries’ own National specification.• Tolerance : ±1.5%High Group : 1209, 1336, 1477, 1633HzLow Group : 697, 770, 852, 941 Hz*DP DIALControls from MAIN through / DP-Terminal.for U.S.Usage, set time to DF signal of 40:60 M/B. DP signal is made of U6 (pcb817). The DC current which flows thru Q2Base is regulated by On/Off switch and turns to DP dial signal with a COUPLER.• CTR 21 does not have telephone capability but has the number 3 and 4 Line Connection. No DP condition but possibilityto get approval only on DTMF Dial based terminal.U.S. Usage CTR21High Freq Level -9.0+2.0/-2.5 -7.0 +1.0/-2.0Low Freq Level -9.0+1.0/-2.0 -11.0+2.5/-2.0