Agilent Technologies 34970A Service Manual page 14

Contents
Chapter 5 Theory of Operation
System Block Diagram 119
Floating Logic 120
Memory 123
Earth-Referenced Logic 124
Power Supplies 125
Front Panel 127
Backplane 128
Analog Bus 128
Digital Bus 128
Internal DMM 129
DMM Block Diagram
Input 130
Input Amplifier 131
Ohms Current Source
AC Circuit 134
A-to-D Converter 136
Switch Modules 138
Switch Module Control 138
Relay Drivers 140
34901A 142
34902A 144
34903A 146
34904A 147
34905A/34906A 148
34908A 149
Multifunction Module 151
Multifunction Control 151
Totalizer 153
Analog Output 154
Digital I/O 155
Chapter 6 Service
Operating Checklist 159
Is the instrument inoperative? 159
Does the instrument fail self-test? 159
Is the Current measurement function inoperative? 159
Types of Service Available 160
Standard Repair Service (worldwide) 160
Express Exchange (U.S.A. only) 160
Repackaging for Shipment 161
Cleaning 161
Electrostatic Discharge (ESD) Precautions 162
Surface Mount Repair 162
To Replace the Power-Line Fuse 163
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