Raytheon Pathfinder 1200 Instruction Manual page 90

37) Control Panel Circuit PCB
The control panel circuit PCB contains the RANGE switch data hold circuit with
LED indicators and RAIN CLUTTER, IR, BRIL, SHM MARKERS control data
generator circuits with RAIN CLUTTER and IR LED's. IC 1 holds the range data
and drives LED indicator. IC2 changes the range data into three bits binary data.
IC3 is a chattering free circuit controlled by the latching pulse of IC6-8. RAIN
CLUTTER signal on IC3-5 and IR signal on IC3-7 are fed to IC4 (dual FF). IC4
output produce ON and OFF control signal alternately every input signal. BRIL
signal-on IC3 -12 and SHM MARKERS signal on IC15 are fed to IC5 and change to
two bits control data. IC6-4 and IC6-6 are used to initialize the control data.
38) Power Supply
The power supply circuit is designed to provide the various power output for the
whole radar from nominal ship's mains of 12 V, 24 V or 32 V de. The power supply
circuit consists of the switching type AVR, the converter, the control circuit, and the
rectifier circuits. The basic circuit of the power supply for 12V and 24/32V operation
is shown in Figure 6-9.
TR501 L501
T401
1
TR 502
C0501
Cont ro I
24/32V
+
Circuit
+
CI
CI6
Input
j
EI
Ed
E2
TR503
L501 T401
1
TR 502
Control
Circuit
12 V
+
Input
CI6
TR501
+
1
CI
EI
Esw
E2
FIG. 6-9 THE BASIC CIRCUIT
(A) For Step Down Operation
While the transistor switch is ON, power is fed to the load (the converter circuit)
via an inductor L501. During the OFF time, the charged energy in the inductor
is continuously fed to the load via a diode CD501. If these switch, times are
denoted by Ton and Toff, the voltage across the diode Ed is such as shown in
Figure 6-10.
6-24