Furuno FAX-30 Service Manual page 13

Power Supply Specification
Input voltage: 10.8 Vdc to 31.2 Vdc
Power consumption: 12 W (Maximum)
Input current: 1.0 A or less (12 V) and 0.5 A or less (24 V)
Protection circuit
PWR circuit is protected by;
Output short-circuit protector; 3.3 V line: U17 includes a protector.
Input low- and over-voltage protector; U3 activates in the voltage range from 6.5 Vdc to
Input reverse protector: Reverse protection diode, CR1
Input over-current protector; 2 A fuse blows out.
Signals between MAIN and RCV boards
MAIN and RCV boards are connected by following signal lines.
MAIN board RCV board
(PH14 pin) (PH14 pin)
#1 #1
#2 #2
#3 (output) #3
#4 (output) #4
#5 (output) #5
#6 (output) #6
#7 (output) #7
#8 (output) #8
#9 (output) #9
#10 (input) #10
#11 (output) #11
#12 (input) #12
#13 (input) #13
#14 #14
5.0 V line: U16 includes a protector.
15 V line: poly switch, RT1
10.2 Vdc and from 32.8 Vdc to 40.5 Vdc.
Signal Name
0 V
0 V
+15 V
+15 V
RCV DDS Strobe signal for DDS setting
RCV PLL Strobe signal for PLL setting
RCV CLK Clock receiving frequency setting
RCV DATA Data receiving frequency setting
RCV BAND Strobe signal for band selection
RCV UNLOCK Synthesizer UNLOCK signal
RCV TEST Self test signal
AF_H FAX: 16290 Hz ± 400 Hz
NAVTEX: 16290 Hz ± 85 Hz
AF_L
0 V
5
Chapter 2 Circuit Description
Remarks