Analog Monitor Section - Fluke 5725A Instruction Manual

5725A
Instruction Manual
latch up by eliminating positive feedback resulting from positive output voltages from
U100. Op amp U105 is simply a low-noise inverting amplifier that scales the sensor
output to 10 dB below the 5700A Oscillator output level. The output of the calibration
circuit, AC/AC, goes to the 5700A during calibration through the analog monitor
section.

Analog Monitor Section

The 16-channel multiplexer, U151, takes a variety of inputs from all analog assemblies
and provides a means of switching them to either a comparator, U154A, or to the B-RCL
line via K152. During normal operation, the multiplexer output is routed exclusively to
the comparator. Calibration requires routing the multiplexer output to the B-RCL line,
which is routed back to the 5700A. The B-RCL line is measured by the precision adc
circuit on the 5700A DAC assembly. All inputs to the multiplexer are scaled so that
inputs are within its ±15V power supply range. Table 4-4 shows the signal name of the
multiplexer input, its description, origin, and purpose.
The state of the multiplexer is controlled by the microprocessor via data latched into
U152.
STANDBY
VOLTAGE
LIMITS(1)
-0.125V
+0.125V
0.26V
-0.26V


1.7V
2.0V
-2.2V




0.08, 2.0V
Note 1: For single limit values, the limit is equal to, or smaller in magnitude to, the value shown.
4-34
Table 4-4. Signals Monitored by the Analog Monitor Section
SIGNAL PHYSICAL
NAME PARAMETER
+400V IM Supply Current
-400V IM Supply Current
+400V M Supply Voltage
-400V M Supply Voltage
VCOM System Supply Common
HVCOM M High Voltage Supply
Common
HVTEMP M Voltage Amp Heat Sink
Temp.
ITEMP M Current Amp Heat Sink
Temp.
ICOMPL M Current Output Stage
Drive Level
I CAL/I FB Shunt Voltage
AC/AC Calibrator Output
HVSENSE Sense Amp Output
DAC OUT DAC Output
FAN M Fan is On or Off
SOURCE
Power Supply
Power Supply
Power Supply
Power Supply
Power Supply
Power Supply
High Voltage Amplifier
Current Amplifier
Current Amplifier
Current Amplifier
High Voltage Sense
High Voltage Sense
High Voltage Sense
Power Supply
4-56.
PURPOSE
Monitoring
Monitoring
Monitoring
Monitoring
Monitoring
Monitoring
Monitoring
Monitoring
Monitoring
Calibration, AC I
Operation
Calibration
Calibration
Monitoring
Monitoring