Pre-Attenuator; Signal Output Amplifier - HP 8112A Operating, Programming And Servicing Manual

Pre-Attenuator

Signal Output Amplifier

Servicing the Shaper and Output Amplifier
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The pre-attenuator circuit is controlled by the microprocessor via
latch U500. Logic signals Kl - K4 control relays K500 - K503 to
provide three levels of attenuation according to the range of output
voltage required.
Table 10.4-2. Pre-attenuator ranges
Attenuation Active Relay(s) Fiual Output Range
The output amplifier amplifies the signal received from the shaper
IC via the pre-attenuator and adds the required offset voltage as
dictated by the HIL and LOL settings. A simplified version of the
circuit is given in Figure 10.4-3
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Figure 10.4-2. Current Mirror
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