4.6 LIU PBA
LIU board is a Line interface unit, and it is a circuit for interfacing a telephone line with a modem. The circuit is consist-
ed of matching transfer to conform to impedance of a receiving telephone line and a circuit to conform to impedance of a
modem.
Also, there are a ring detect circuit to detect a ring signal from a switchboard and a surge absorber to protect it from a
thunderbolt located on a line input unit.
4.7 OPE PBA
OPE board is consisted of various function keys and LCD to display an operation of key. MICOM creates
a circuit with using HT48R50 MICOM of HOLTEC CO. and applies LED and LCD. A communication
method with a CPU of a main board is UART, and related signals are /Reset, TXD, and RXD.
Samsung Electronics
Ring Detect Circuit (PC814)
SUMMARY OF PRODUCT
Relay
Tel-Line Jack
Surge
Absorber
Service Manual
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