1 0.4
Servicing the Shaper and Output Amplifier
Theory of Operation
Introduction
The shaper and output amplifier circuits are located on the main
board Al and are divided into the following parts:
•
Bus Latch
•
Shaper IC
•
Current Mirror
•
Pre-Attenuator
•
Signal Output Amplifier
•
Output Attenuator
•
Trigger Output Amplifier
•
Level Check Circuit
These circuits are the last in the signal path.
Bus Latch
An eight line decoder U500 latches data from the data bus when
enabled by WS2/LRC
(
sent by the microprocessor) and outputs
the data to the shaper IC where it is used to control pulse
shaping/correction and to select output mode and complement.
The data is also applied to the pre-attenuator where it controls the
attenuation and output disable functions via relays K500 to K504.
Shaper IC
The shaper IC U401 , shown in Figure 10.4-1,is a high-performance
signal-control circuit which, depending on the state of its mode
inputs
(
pins 22 and 23), produces outputs as shown in Table 10.4-1.
Servicing the Shaper and Output Amplifier 10.4-1
Summary of Contents for 8112A
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