Furuno FCV-1200L Service Manual page 13

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 Communicates with CPU on PNL board in Control Unit.
02P6269 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 Transmits and receives signal from/to transducer.
02P6271
POWER board Generates -5V, 5V, 5VA, 12VA, 12VPD, VTX L and VTX H by switching
02P6270 regulator circuit.
FIL board Eliminates common mode noise on ship's main line
02P6274
CON board I/O board for Net Sonde and Water Temperature Sensor
02P6262
EXIF board Interfaces signals between external unit and processor unit
02P6278
02P6269
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.
10