Fluke 8508A Service Manual page 36

8508A
Service Manual
AC + DC
DC V
I DC
and
I AC
Input Signal
Switching Relays
A6 Rear Input
2-4
2-Wire
4-Wire
Range
Range Selection
AC
Range Selection
DC
10:1
Preamp
Range Switched
Precision Shunts
Relay Control and
Optically Isolated
Relay Drivers
Serial Interface
Assembly
Figure 2-1. 8508A Functional Block Diagram
A3 Ohms PCA
I to R Converter
-15 V
A2 AC PCA
RMS
Rectifier
Converter
AC
Preamp
A1 DC PCA
DC AMP
(Chopper
AD MUX
Stabilized)
Internal
Reference
In-guard
Out-guard
A4 Digital PCA
Out-Guard Power Supply
+5 V +8 V, +17 V
Keyboard and
Display Memory
A5 Bezel Assembly and
A5A1 Display PCA
Lo-Pass
Output
Filter
Buffer
A to D
Converter
(ADC)
In-guard
Power Supplies
250 VAC
+5 V +8 V
+15 V
–8 V
+36 V
Line
Power
Rear Panel
IEEE (GPIP)
to
IEEE-488
Serial
(GPIB)
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