Furuno CH-270 User manual

COLOR SEARCHLIGHT SONAR
CH-270

Your Local Agent/DealerYour Local Agent/Dealer
9-52 Ashihara-cho,9-52 Ashihara-cho,
Nishinomi
y
a 662-8580, JAPANNishinomi
y
a 662-8580, JAPAN
Tele
p
hone :Tele
p
hone : 0798-65-21110798-65-2111
Fa
x
Fa
x
0798-65-42000798-65-4200
::
F
IRST EDITION :
F
IRST EDITION : JULJUL.. 20042004
Printed in JapanPrinted in Japan
A
ll ri
g
hts reserved.
A
ll ri
g
hts reserved.
Pub. No.Pub. No. SME-13220-ASME-13220-A
*00015124100**00015124100*
*00015124100**00015124100*
(( KAOKKAOK )) CH-270CH-270 * 0 0 0 1 5 1 2 4 1 0 0 ** 0 0 0 1 5 1 2 4 1 0 0 *
*SME13220A00**SME13220A00*
*SME13220A00**SME13220A00*
* S M E 1 3 2 2 0 A 0 0 ** S M E 1 3 2 2 0 A 0 0 *

CONTENTS
SYSTEM CONFIGURATION................................................................................1
1. FUNCTION OF EACH UNIT
1.1 Display Unit (MU-100C)..................................................................................3
1.2 Control Unit (CH-252)......................................................................................4
1.3 Transceiver Unit (CH-273) ...............................................................................5
1.3.1 CPU Board (06P0258)............................................................................5
1.3.2 TRX Board (06P0241) ...........................................................................6
1.3.3 PWR Board (06P0242)...........................................................................7
1.3.4 PRA Board (06P0259)............................................................................8
2. FUNCTIONAL DESCRIPTION
2.1 Transmission.....................................................................................................9
2.2 Reception..........................................................................................................9
2.3 Raising/Lowering Transducer.........................................................................12
2.4 Tilting Transducer...........................................................................................13
2.5 Training Transducer........................................................................................15
2.6 Braking Tilt/Train Motor ................................................................................17
3. CHECK AND ADJUSTMENT
3.1 Test Points.......................................................................................................18
3.2 LED Indication................................................................................................21
3.3 Adjustment......................................................................................................22
4. PARTS LOCATION
4.1 Display Unit....................................................................................................24
4.2 Control Unit....................................................................................................26
4.3 Transceiver Unit..............................................................................................26
5. MAINTENANCE
5.1 Replacement of Grease Cotton .......................................................................32
5.2 Soundome (D) Replacement...........................................................................32
5.3 Transducer Replacement.................................................................................34
5.4 Tilt Gear Box Replacement.............................................................................35
5.5 Slip Ring Replacement....................................................................................36
5.6 Carbon Brush Replacement ............................................................................37
5.7 Tilt Code Disk Alignment...............................................................................38
6. TROUBLESHOOTING
6.1 Flow Chart ......................................................................................................40
Appendix A CH-250 vs CH-270..............................................................................46
Mechanical Parts List ................................................................................... 48
Exploded view .............................................................................................D-1
Schematic Diagram .......................................................................................S-1

1
SYSTEM CONFIGURATION
CH-270 (250 stroke)
HULL UNIT
SPEAKER
DATA/VIDEO OUT
MOTION SENSOR
12-32VDC
12/24 VDC
12-32 VDC
Speaker
Motion Sensor
External
Monitor
Control Unit
Display Unit
Navigator DISPLAY UNIT MU-100C
TRANSCEIVER UNIT
CH-273
INTERFACE UNIT
IF-8000
Remote
Controller
: Standard
: Option
: Local Supply
CONTROL BOX
CONTROL UNIT CH-252
SECTOR TRAIN RANGE TILT
MAIN
SUB FULL
HALF FAST
SCAN
BRILL TARGET MENU
R/B EVENT
CUSTOM MODE
DISPLAY MODE
POWER
XDR
GAIN
HULL UNIT
CH-184
Note 1: The CH-270 is supplied
with or without a display
unit. For connection of
locally supplied monitor, an
interface unit is provided.
The drawing above shows
the system configuration
with the MU-100C.
Note 2: For use of a locally
supplied monitor, connect
it and control unit to the
interface unit.

2
CH-270 (350 stroke)
HULL UNIT
SPEAKER
DATA/VIDEO OUT
MOTION SENSOR
12-32VDC
12-32 VDC
Speaker
Mot on Sensor
External
Mon tor
Control Un t
D splay
Un t
Nav gator
CONTROL UNIT CH-252
DISPLAY UNIT MU-100C
TRANSCEIVER UNIT
CH-273
INTERFACE UNIT
IF-8000
Remote
Controller
HULL UNIT
CH-181
12/24 VDC
Note 1: The CH-270 s suppl ed
w th or w thout a d splay
un t. For connect on of
locally suppl ed mon tor, an
nterface un t s prov ded.
The draw ng above shows
the system conf gurat on
w th the MU-100C.
Note 2: For use of a locally
suppl ed mon tor, connect
t and control un t to the
nterface un t. : Standard
: Opt on
: Local Supply
GAIN SECTOR TRAIN RANGE TILT
MAIN
SUB FULL
HALF FAST
SCAN
BRILL TARGET MENU
R/B EVENT
CUSTOM MODE
DISPLAY MODE
POWER
XDR

3
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
Sw tch ng 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.

4
1.2 Control Unit (CH-252)
Figure 1.2 shows the block diagram of the Control Unit.
MU100C
Figure 1.2 Block Diagram of Control Unit
The control unit consists of the control panel and PNL board.
The CPU on PNL board reads the settings on the control panel and sends the data to the CPU in
transceiver unit through serial data communication bus.
The CPU on PNL board switches on and off LEDs and activates the buzzer.

5
1.3 Transceiver Unit (CH-273)
The Transceiver Unit consists of CPU board (06P0258), TRX board (06P0241), PWR board
(06P0242), and PRA board (06P0259).
Major function of CPU board is;
1) To control transmitting and receiving circuits.
2) To generate train/tilt control signal.
3) To generate transducer raising/lowering control signal.
4) To generate analog RGB, H-SYNC, Y-SYNC, and clock signals for the display unit.
5) To read settings on the control panel.
6) To receive and send I/O signals through NMEA port.
7) To receive data from the motion sensor.
8) To generate character data.
1.3.1 CPU Board (06P0258)
The heart of CPU board is a main CPU (U17) and a Gate Array (U30).
The gate array (U30) outputs KP signal, TX carrier signals (TX0 and TX1), RGB signal,
H/V-sync signal, AGC on/off signal (AGC), power reduction signal (TXL), TX frequency data
(F0 to F1), Direct Digital Synthesis (DDS, U19)-related signal, and volume control signal
(VOL0 to VOL7).

6
1.3.2 TRX Board (06P0241)
Figure 1.5 shows the block diagram of TRX board. The TRX board contains a transmission
circuit, a receiver circuit, and a audio amplifier circuit.
U2 TP3
Loudspeaker
TP5
TP8
TP6
TP10 VG
TP9
Figure 1.3 Block Diagram of TRX Board (06P0241)
Transmitter Circuit
Transmission carrier signal "TX0/TX1" from CPU board is amplified by Power MOS FET
amplifier circuit (Q4, Q6, Q7, Q9, Q10, Q12, Q13, and Q15). The output level of TRX board is
determined with +B voltage ("VTX" signal).
Receiver Circuit
The signal received by the transducer is sent to the wide band filter circuit through PRA board,
and then, mixed with a carrier signal "LCL" to convert it into IF signal (455 kHz). The CPU
board generates the carrier signal. The IF signal is amplified in accordance with GAIN/TVG
settings, and then rectified. The rectified signal is sent to CPU board and AGC control circuit.
Audio Amplifier Circuit
The 455kHZ IF signal is also sent to the audio amplifier circuit to drive the loudspeaker.

7
1.3.3 PWR Board (06P0242)
Figure 1.6 shows the block diagram of PWR board.
The power on/off switch in the control unit generates PSW-H and PSW-L signals to send them
to PWR board via the display unit. The PWR board generates 5V, -5V, 12V 12VD, and +B
voltage (VTX).
The 12VD voltage (12VA) is supplied to the display unit via CPU board. The VTX voltage is
determined with TXV voltage from CPU board.
VTX
Figure 1.4 Function diagram of the PWR Board (06P0242)
58
Figure 1.5 Shows power supply lines in the system.

8
1.3.4 PRA Board (06P0259)
The preamplifier (PRA) board, 06P0259 locates in the transceiver unit. Figure 1.6 shows the
block diagram of PRA board.
From Transm tter Match ng
Transformer
Trap C rcu t
To Transducer
Resonance C rcu t
Pre-Ampl f er
Rece v ng
S gnal Output
Figure 1.6 Block Diagram of PRA board

9
2. FUNCTIONAL DESCRIPTION
2.1 Transmission
Fig. 2.1 shows the signal flow in the transmitter.
The TX signal, TX0 and TX1, generated by CPU board (06P0258) is amplified by TRX board
(06P0241). The output of the power amplifier is impedance-matched with the transducer with a
matching transformer on PRA board (06P0259).
The +B voltage (VTX) from PWR board (06P0242) determines the transmitter output level
according to menu settings.
Table 2.1 Transmission level and control voltage
Signals Voltage Measuring Points
TX output 1019 Vpp Output of matching transformer on PRA board
TX output 713 Vpp Between TP6 and TP8 on TRX board
VTX (+B voltage) 77 V Resister "R13" on TRX board
Control Voltage TXV 3.0 V TP1 on CPU board
TX output level with
Dummy Load 592 Vpp Between TP6 and TP8 on TRX board with Dummy Load
2.2 Reception
Fig. 2.2 shows the signal flow in the receiver.
The echo received by the transducer is amplified by the Pre-Amplifier board and mixed with the
local carrier signal by the mixer U2 to generate 455 kHz IF signal.
The output of the buffer amplifier Q5 is sent to the rectifier, CR8/CR9, and then output to CPU
board from J3 #1.
The gain control signal (TVG), 0 to 5 VDC, is generated by CPU board according to control
panel setting. The TVG/AGC control circuit reshapes the TVG signal and output TVG signal,
0.5 to 1.7 VDC to amplifiers. When GAIN control is set to maximum, 1.7VDC is output.
Receiving the signal rectified by U7, the AGC feedback circuit also controls the TVG signal
level.
The output of TRX board is converted into digital data by A/D converter "U35" and applied to
Gate Array "U30" on CPU board.
The output of Gate Array is converted into R/G/B signal and sent to the display unit from #1, #2,
and #3 of J1.

10
58
59
6
6
DR 06P0154
Hull Unit
XDR
(Slip ring)
Figure 2.1 Signal Flow in Transmitter

11
Hull unit
XDR
(Slip ring)
66
59
58
Figure 2.2 Signal Flow in Receiver

12
2.3 Raising/Lowering Transducer
See the simplified circuit diagram below. The CPU generates rising and lower control signals,
UPC and DNC. The DNC signal is generated when the down key is pressed and the UPC signal
is generated when the up key is pressed. These signals change the status of R/L CONT signal.
Lowering Operation
The DC motor in the hull unit lowers the transducer, receiving R/L CONT signal from CPU
board below.
1) When R/L CONT signal is HIGH, U9 on DRV board is led into conductive condition, causing
that K1 activates.
2) Terminals ①and ②of the motor are connected to the negative and positive lines
respectively to power the DC motor. The motor is connected to the positive line through the
lower limit switch.
3) When the lower limit switch K3 is kicked, R2 is connected across the motor as a brake.
Hull un tDRV board
CPU board
LOWER
J10
#3
#1
J2
#1
#2
R/L Cont
S gnal
RAISE
Figure 2.3 Raise/Lower Circuit
Raise Operation
The transducer raises in the following sequence.
1) When R/L CONT signal is LOW, U9 is led into cut off condition, causing that K1 inactivates.
2) Terminal ①of the motor is connected to the positive line through the relay contact and the
upper limit switch S2, while terminal ②to the negative line through the relay contact. As a
result, the motor rotates to raise the transducer.
3) When the transducer is completely hoisted up, the upper limit switch is kicked, causing that
the positive line is disconnected from terminal ①and a brake resistor R1 is connected across
the motor.
NOTE: When the display unit is turned off, the R/L level being fed from the display unit
becomes LOW, and raise operation is executed automatically.
While the transducer is raising (lowering), the LED above up (down) arrow key on the control
unit blinks and it lights when completed.
#1
J2
L: Raise
H: Lower

13
2.4 Tilting Transducer
Fig. 2.4 shows the simplified tilt control circuit.
The 4-phase stepping motor is controlled by a phased generator U3 on DRV board.
The CPU outputs a clock signal (TIM 1) to the phased pulse generator U3. Receiving the clock
signal, the phased pulse generator outputs HIGH level in the sequence shown in Table 2-2, and
the motor rotates accordingly. The phased pulse generator outputs HIGH level in reverse
sequence when the H/L condition of TI DN/UP signal (TIM2) is changed and the motor rotates
in opposite direction.
Table 2.2 Clock Cycle (DN/UP = H) Clock Cycle (DN/UP = L)
Output 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8
Ø1 L L L L L H H H H H L L L L L H
Ø2 L L L H H H L L L H H H L L L L
Ø3 L H H H L L L L L L L H H H L L
Ø4 H H L L L L L H L L L L L H H H
As shown in Fig. 2.4, a disc with slits is coupled to the motor through gears to detect tilts of +8°,
-30°, and -93°. The slits activate the sensors (photo interrupters) which generate TI8 and TI93
signals. Using these signals, the CPU reads the tilt angle as shown in table below.
Table 2.3
+8° Signal (T18) -93° Signal (T193) Tilt
High Low +8°
High High -30°
Low High -93°
At every power-on, the CPU initializes the tile angle to –30°. If the CPU does not detect the tilt
of 30°, error message TILT NG appears.

14
Figure 2.4
TRANSCEVER UNIT
CPU
(U17)
CPU
J2
TI CLK
(TIM1)
TI UP/DN
(TIM2)
#5 #6
#92
#197
CR41 CR18
TI-93
TI8
U39 U33
J10 #11 #12 #9 #10

15
2.5 Training Transducer
Basically the circuit is the same as the tilt control circuit. See the simplified circuit diagram on
the next page.
The phased pulse generator U5 drives the train motor with TR CLK (TRM1) and TR CW/CCW
(TRM2) signals from CPU board.
A slit on the rotary disc generates a “Heading” signal (TR FORE) when the transducer faces
toward the bow. The TR FORE signal is sent to the CPU as TR 0°. At every power-on, the CPU
searches TR 0° signal. If the CPU does not detect TR 0° signal, error manage TRAIN NG
appears.
The transducer rotates in either “normal” or “fast” mode. In the normal mode, transmission and
reception are made while the transducer is rotating in 6° steps. In the fast mode, the transducer
moves in 12° steps after transmission and reception are completed.

16
Figure 2.5
TRANSCEIVER UNIT
CPU
J2 #3 #4
#3 #4
#5 #6
J10 #5 #6 #7 #8
CR16
U17
U34
#191
R104 R105

17
2.6 Braking Tilt/Train Motor
Fig. 2.6 shows the power supply circuit for the tilt motor.
U2 is a retrigger able one-shot multivibrator of which Q output is held “H” while TI CLK is
continuously applied to “Ain” pin.
Q1 and Q2 are “OFF” and “ON” respectively when TI CLK signal is applied to U2. When TI
CLK signal is absent, outputs, Q and Q are held to LOW and HIGH respectively, causing that
Q1 goes ON and Q2 OFF. Thus, 6V is applied to the tilt motor as “brake” signal through R4.
Power supply voltage 13.5V for the train motor is generated in the same way as the tilt motor.
DRV Board
(06P0154) 06P0147
Figure 2.6 Power Supply for Tilt Motor
Vpp=20V (24Vdc set)
Vpp= 8V (12Vdc set)