Kongsberg Simrad RA83, Service Manual

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Step-Up
Driver A,B
Transformer A,B
Voltage
Regulator
(
10V
)
Voltage
Regulator
(
12V
)
Switching
Driver
Over
-
Voltage
Protection
(
50V
)
Power Switch
Start-Up
Circuit
Low
-
Voltage
Protection
(18V)
Switching
OSC
(
43kHz
)
Switching
Driver A,B
Switching
OSC
(
56kHz
)
Over-Current
Detection A,B
5V
Rectifier
Voltage Difference
Detection
Over
-
Voltage
Protection
(
42V
)
Reverse
Voltage
Protection
Noise
Filter
Logic Circuit
Ship's Supply
24V
Rectifier
-
12V
Rectifier
250V
Rectifier
250V
Control
Over
-
Current
Protection (250mA)
12V
Rectifier
12V
(
SCANNER
)
Control
from Transformer A
A
B
12V
Rectifier
40V
Rectifier
from Transformer B
(3Ax2)
(45V)
(18
～
41.6Vdc)
Motor drive supply voltage
Over-Voltage
Protection
(6V)
Fig.-2.2.2 Block Diagram of POWER PCB
The other circuit function in the POWER PCB is:
U7 (uPC1093T)
constant current controller for U2
Q28 to Q32 +250V(High Voltage) control
Q4, Q6 to Q14 scanner 12V power control.
(for sleep, navi-display, or monitor mode)
Q26, Q27, T2 to CR17 +40V for motor supply voltage.
2.2.2 LOGIC PCB (E47-700B)
(1) Video Processing
The AA239AFP, U9 is specially designed LSI for signal processing. The U9 includes a video
amplifier, a video and a trigger separator, a heading and azimuth pulse separator, and a STC, a
FTC control circuit. The STC and FTC functions are controlled by a D/A (Digital to Analog)
MB88346BPF, U6.
.
After analog signal processing the video data fed into comparator in the U9. The comparator
output 7 digits video data lines. Digital video data are processed in KCD-64,U21 LSI. The
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