Furuno CH-270, Руководство по обслуживанию

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1. FUNCTION OF EACH UNIT
1.1 Display Unit (MU-100C)
The Display Unit (MU-100C) consists of DISP board (06P0238), LCD Inverter board, and LCD
unit. Figure 1.1 shows the block diagram of Display Unit.
LCD I/F
H-SYNC, V-SYNC, CLK
LCD Unit
5V
TP8
A/D CON.
U24
U9
TP9
AD5V
Switching Regulator
U20, Q3, Q4
FUSE
F1 3A
12VDC
10 to 16VDC
Inverter
R, G, B,
BRILL
R, G, B,
HSNC, VSNC, CLK
TP7
12V
5V LCD
TP1
TRXTD-A/B, CONTD-A/B, PWRSW-H/C
DISP Board
U6
U1,Q1,Q2
Figure 1.1 Block Diagram of Display Unit
The DISP board contains LCD interface circuit and a power switching regulator circuit. The
LCD interface circuit converts the analoge R, G, B signals from the transceiver unit into six bit
digital R, G, B signals with a A/D converter. H-SYNC, V-SYNC, and CLK (dot clock) signals
from the transceiver unit are also supplied to the LCD unit through the LCD Interface circuit.
The power switching regulator generates 5V for digital circuit, AD5V for the A/D converter, and
12V for the LCD inverter board.
The LCD unit consists of LCD module (10.4 inch's screen, TTF color LCD), LCD control board
and a fluorescent lamp for back-lighting.
The LCD inverter board generates high voltage for the fluorescent lamp, and it's pulse length is
controlled by the YC signal from the transceiver unit to adjust LCD brightness.