Furuno FCV-1200L, Service Manual

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The processor unit consists of the MAIN board (02P6269), ES board (02P6271), POWER board
(02P6270), FIL board (02P6274), CON board (02P6262), and EXIF board (02P6279).
The EXIF board is optional supplied.
Following table shows the principal functions of each PC board.
PC board
Functions
MAIN board
02P6269 Communicates with CPU on PNL board in Control Unit.
Generates character data.
Generates transmission signals.
Processes received signal.
Generates R/G/B, H-SYNC, V -SYNC, and YC signals.
Inputs and outputs NMEA data.
Generates TVG curves and local carrier signals for receiver circuit
Controls VTX voltage on POWER board.
Detects status signals set on ES and EXIF boards.
ES board
02P6271 Transmits and receives signal from/to transducer.
POWER board
02P6270 Generates -5V, 5V, 5VA, 12VA, 12VPD, VTX L and VTX H by switching
regulator circuit.
FIL board
02P6274 Eliminates common mode noise on ship's main line
CON board
02P6262 I/O board for Net Sonde and Water Temperature Sensor
EXIF board
02P6278
02P6269 Interfaces signals between external unit and processor unit
3.3.1 PWR Board (02P6270)
Figure 3.4 shows the block diagram of the PWR board.
The power circuit is activated when the PSW-H and PSW-L signals are short-circuited by the power
switch in the control unit. The PWR board generates 5V, -5V, 12VP, 12VPD, and VTX voltage.
The 12VPD is source voltage of the Display Unit. The VTX voltage is supplied to the transmission
amplifier circuit on the ES board (02P6262). The VTX voltage is determined by the VTX CONT
H/L signals which are generated on the MAIN board in accordance with the manual or auto-setting
of the "SUPPLY VOLT" in the "XDCR SETTING" menu.