Service manual

DCB, DCFCB and DCFCTB Models
41
Theory of Operation
Table 7 Parts List
FEDERAL PART NO.
LOCATION
DESCRIPTION
107A907A
C1,C2,C5
CAPACITOR, MONO, 33 UFD
107A905A
C3
CAP, MONO, .01 UFD, 50V
1071033A
C4
CAPACITOR, MONO, 1 UF, 50V
128A217A
IC1
I.C., 8 VOLT, MC78L08ACP
128A045A
IC2
I.C., LM358, DUAL OP-AMP
128A123A
IC3
I.C., MC14001B
128254-01
IC4
I.C., TLP321GB OPTO
288462A
CS1
CURRENT SENSOR
105A276A
POT 1, POT 2
POTENTIOMETER, 100 K OHM
140351-01
PIN 1, PIN 2,
CONN, HEADER, 1 POSITION
PIN 3, PIN 4
140A235A-01
J1
CONNECTOR, 4 POSITION
301A122
J2,JU1,JU2
WIRE,BUSS,SOLID,22 GA.
100A247
R1
RESISTOR, CF, 820 OHM, 5%
100A262
R2
RESISTOR, CF, 100 K OHM 5%
103469B
PCB, ADJ. CURRENT SENSOR
Rotator Motor Current Sensor Theory of Operation
Overview
The Current Sensor board, 2005221 Rev B, is mounted on the backplane under
the DC contactors. It monitors the DC current of the rotator motor. It scales the
voltage reading to allow direct reading of the current passing through the sensor
and employs a window comparator which signals that the current is between a
lower and an upper limit.
Features
 Easy direct reading of current passing through the sensor
 Fixed window comparator, no adjustment needed
 Accurate to +/- 5%
Electrical Specifications
Input Voltage
7 VDC – 30 VDC
Input Current
<30 mA maximum
Measurement Current Ranges
0 to 5 Amps, 0 to 5 VDC at TP3
0 to 15 Amps, 0 to 5 VDC at TP3
Window Comparator Thresholds
JP3 and JP4 not jumpered
0.34 VDC min., 1.50 VDC max.
(0.34 and 1.5 Amps)
JP3 and JP4 jumpered
1.00 VDC min., 2.67 VDC max.
(3.0 and 8 Amps)
Window Comparator Output
Open collector, sink </= 500 mA