5725A
Instruction Manual
High Voltage Amplifier (A3) |
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The High Voltage Amplifier assembly, operating with the
The High Voltage Amplifier assembly consists of an input amplifier, integrator, window comparator, input clamp, transconductance and cascode stage, midstage, midstage
The High Voltage Amplifier drives the primary winding of the appropriate signal transformer depending on the frequency of operation. Signal transformers are interfaced to the High Voltage Amplifier via connector J604. Relays that select signal transformers are mentioned under the heading "Signal Transformers" further on.
The High Voltage Amplifier assembly uses the ±400V supplies from the Power Supply assembly. Lethal voltage appears on the heat sink assemblies. Do not open the 5725A cover without referring to the access procedures and warnings in Section 6.
Figure
Input Amplifier |
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The input amplifier, U602, is an op amp whose input comes from HV IN on J653 through R623 and R621. HV IN is the 2.2V to 11V ac signal generated by the 5700A and routed through the High Voltage Sense assembly. The input amplifier has a high- frequency gain of 5.5, but because feedback resistor R622 is