LUDLUM 12-4 User Manual page 5

Model 12-4
Technical Theory of Operation
Main Board (Drawing 464 × 275, 3 sheets)
Input
Amplifier
Discriminator
Audio
Scale Ranging
Digital Analog Converter
Ratemeter Drive Circuit
HV Meter Drive
Battery Test
HV Power Supply Board (Drawing 464 × 243)
Switching Convertor
Feedback
Voltage Control
Filtering
Recycling
Parts List
Model 12-4 Survey Meter
Main Board, Drawing 464 × 275
HV Power Supply Board, Drawing 464 × 243
Wiring Diagram, Drawing 464 × 309
Model 42-31H Neutron Detector
Drawings and Diagrams
Ludlum Measurements, Inc.
Technical Manual
8
8-1
8-1
8-1
8-1
8-1
8-2
8-2
8-2
8-2
8-2
8-3
8-3
8-3
8-3
8-3
9
10
10-1
10-1
10-4
10-5
10-5
11
May 2016