GE Corometrics 170 Series Service Manual page 100

To Main Board Front End
FECG/IUP Connector
Isolated Side
Connector
RA
LA
RL
–PRESS
+PRESS
–4 V
FECGEN
IUPEN
TOCOEN
US1EN (174 only)
Supplies
5-40
Theory of Operation: FECG/IUP Board Theory of Operation
• FECG Low Noise
Differential
Amplifier with
Protection Circuitry
• RL Drive Circuitry
• High-Pass Filter
Pressure Differential
Amplifier with
Protection Circuitry
• +4 V Reference
• IUP Detection
Circuitry
To TOCO Enable
Model Line Optical
Isolation for FECG,
IUP, US1 (174 only)
and TOCO
Isolated Power
Isolated
Supply
Figure 5-22. FECG/IUP Board Block Diagram
170 Series Monitor
Optical
Isolation
Optical
Isolation
FECGEN
IUPEN
TOCOEN
US1EN (174 only)
+12 V (173); +11.6 V (174)
Power Supply
Q, Q*
2000947-004
To Main Board A/D
Converter for Processing
Unisolated Side
Connector
Filtering
and Gain
Stages
• Gain and Offset
Adjustments
• Filtering Stages
144 KHz (173 only)
144 KHz
CLEAR*
Control PAL
174 Only
Revision C