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Models 2510 and 2510-AT
Troubleshooting
4-11
A constant current is forced through the DUT (thermistor) as well as a reference resistor (in
this example, 10k
Ω
for the 10k
Ω
range). As various phases of the measurement cycle, the volt-
ages across the DUT and 10k
Ω
reference resistor are measured, and the actual DUT resistance
is computed from the ratio of the two voltages. Since the resistance of the 10k
Ω
reference
resistance is accurately known (as determined during instrument calibration), the DUT resis-
tance and a given temperature can be accurately determined, and internal software converts the
resistance into an equivalent temperature reading.
A/D converter
The Model 2510 unit uses a multi-slope charge balance A/D converter with a single-slope
run-down. The converter is controlled by a gate array. Commands are issued by the MPU to the
gate array, and the gate array IC sends A/D reading data back to the MPU for calibration and
processing.
PID hardware loop control
Figure 4-7 shows an overall diagram of the hardware aspects of the PID control loop.
68332
HDAC
U127
ADC
2
Ω
MUX
U142
U147
ITHP
0.1
Ω
VTHP
REF
ZERO
THP_FBK
PC_TEMP
+15V MEAS
TEMP_REF
“D”
Amplifier
U151
Figure 4-7
PID hardware control loop
2510-902-01 (E - Mar 2010)(Service).book Page 11 Tuesday, March 16, 2010 1:04 PM
Содержание TEC SourceMeter 2510
Страница 3: ...2510 902 01 E Mar 2010 Service book Page 2 Tuesday March 16 2010 1 04 PM...
Страница 14: ...1 PerformanceVerification 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
Страница 28: ...2 Calibration 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
Страница 54: ...3 RoutineMaintenance 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
Страница 58: ...4 Troubleshooting 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
Страница 76: ...5 Disassembly 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
Страница 82: ...6 ReplaceableParts 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
Страница 92: ...A Specifications 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 2 33 PM...
Страница 96: ...B CalibrationReference 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
Страница 110: ...C CalibrationProgram 2510 902 01 E Mar 2010 Service book Page 1 Tuesday March 16 2010 1 04 PM...
Страница 119: ...2510 902 01 E Mar 2010 Service book Page 4 Tuesday March 16 2010 1 04 PM...