Tektronix DM 5010, Инструкция по эксплуатации

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Maintenance— DM 5010
Fig. 7*9. Over-voltage protection and function switching
waveform.
Fig. 7-10. DCV Signal Conditioner and Charge-Balancing
Converter waveform.
If the measured voltage is correct, troubleshoot the next
stage, according to part 7b. If incorrect, check the compo­
nents listed in Table 7-11 for the indicated symptoms.
If no error is found, check the final stage of the converter
in part 7c. If an error is detected, check the components
listed in Table 7-12 for the DM 5010 symptoms.
Table 7-12
RMS CONVERTER FAULTS
Table 7-11
RMS CONVERTER FAULTS
Symptom
Component
Error occurs in ACV mode but
not in ACV +DCV mode
C1621
Error occurs in ACV+DCV
mode with a de or low fre­
quency ac input
K1621, R1621
Error occurs in all ranges
R1603, R1501, K1621,
U1500, C1605, C1607,
C1609, C1503, C1505,
+ and -12 V supplies
Error occurs in 200 mV, 2 V
ranges
R1501, C1505, C1503
Error occurs in 20 V range R1403, R1401, C1403,
C1504
Error occurs in 200, 700 V
ranges
R1309, C1311
Symptom
Error occurs in all ranges
Error occurs in 200 mV,
200 V ranges
Error occurs in 2 V, 20 V,
700 V ranges
Component
R1307, R1201, U1200,
+ and — 12 V supplies
R1201
R1211, K1201
c. To check the final converter stage, move the digital
multimeter high lead to U1100-8 (low lead remains at
TP1701). Check that the measured de voltage is equal to
the rms value of the applied input, scaled to a maximum of
2 V for a full scale input. If an error is detected, check
U1100, Cl 101, C1103, C1001, and R1101. if no error is
found, check Q1217 on the ADC board (diagram 1). If
Q1217 is good, make sure the A/D Converter is functioning
properly by measuring a de input in the DCV mode. If not,
refer to the A/D Converter and De Voltage Measuring Cir­
cuits troubleshooting information.
b. To check the second stage of the RMS Converter,
move the digital multimeter high lead to TP1201 (low lead
remains at TP1701). Set the applied input voltage to a full
scale value for the DM 5010 range being checked. Check
that the nominal ac voltage measured is as listed below for
the DM 5010 range.
DM 5010 Range
200 mV —200 V
700 V
Nominal Ac Voltage
2 V
0.7 V
9. OHMS CONVERTER, RMS Board, Diagram 3
To troubleshoot the Ohms Converter, place the RMS
board on an extender board and set the DM 5010 to the
OHMS mode, with the range (in STEP mode) and input con­
dition as listed in Table 7-13. Measure the voltage between
the component listed in the table and ohms ground. If the
voltage is outside the limits listed, check the designated
component.
ADD JAN 1982
7-17