Fluke 5700A Series User Manual

5700A/5720A Series II Calibrator
Service Manual
5-50
10 k
HR2
SHUNT
1.2
R14
2V ac
±10%
K9C, K8C,
K7A, K5D,
K10, K13
SCOM
Ω
Ω
F5-11.EPS
Figure 5-11. Verifying the 220 mA Range of the 22 mA/220 mA Amp Circuit
9. Check the POS. FB BUFFER. Set the Calibrator to 200 mA, standby. Set the external
ac reference to 4.6V at 1 kHz. Using a DMM measure the ac voltage at pin 5 of the
HR2 resistor network and Note the reading. Next, measure the voltage at TP4 and
verify it is the same as the previous Noted reading ±0.1%. If a failure is detected,
check U3, K5B, K6B, K8B, K9B, and the associated components.
10. Check the I-GUARD BUFFER. Set the Calibrator to 200 mA, standby. Set the
external ac reference to 4.6V at 1 kHz. Measure the ac voltage at TP4 with a DMM
and Note the reading. Next, measure the voltage at U4 pin 6 and verify it is the same
as the previous Noted reading ±0.01%. If a failure is detected, check U4 and its
associated components.
Note
Replace or reconnect jumper E1 and remove the external ac reference
from the Current/Hi-Res assembly before continuing.
11. Check the Input Switching. Set the Calibrator to 2 mA dc, operate. Using a DMM,
measure the dc voltage at TP1 (common to TP2) and verify it is 20V dc ±0.25%.
Next, set the Calibrator to ac 2 mA at 1 kHz operate and measure the ac voltage at
TP1 and verify it is 20V ac ±25%. If a failure is detected, check K1, Q20-Q23, and
their appropriate drive circuitry.
12. Check the Z1 resistor network. Set the Calibrator to 2 mA dc, operate. Using a DMM
measure the dc voltage at pins 8 and 3 of Z1 and verify they are 1.818V dc ±0.35%.
If a failure is detected, check Z1 and the HR2 hybrid.
13. Check the CURRENT/COMPLIANCE VOLTAGE MONITOR. Connect a 10Ω 1%
resistor across the Calibrator output and set the Calibrator to 200 mA at 1 kHz,
operate. Using a DMM measure the ac voltage at the OUT HI binding post and edit
the current output until it measures 2.0V ac ±0.01V. Next, measure the dc voltage at
TP9 and verify it is 0.238V dc ±10%. If a failure is detected, check U5, U6, and the
associated components in the CURRENT/COMPLIANCE VOLTAGE MONITOR
circuit.
14. Check the COMPLIANCE LIMITER. Connect a shorting jumper across the
Calibrator output and set the Calibrator to 2 mA dc, operate. Using a DMM monitor
the dc voltage at TP4. Remove the shorting jumper at the Calibrator output. The
voltage at TP4 should not exceed 11V ±5% before the Calibrator trips to standby. If a
failure is detected, check Q24, Q25, CR10, CR11, and the associated components in
the Compliance Limiter Circuit.

Fluke 5700A Series Specifications

General

Type	Multifunction Calibrator
Operating Temperature	0°C to 50°C
Storage Temperature	-40°C to 70°C
Humidity	10% to 90% non-condensing
Frequency Range	10 Hz to 1 MHz
Accuracy	Varies by function and range. See manufacturer's specifications for details.
Output Stability	Varies by function and range. See manufacturer's specifications for details.
Power Requirements	50 Hz to 60 Hz