Agilent Technologies AGILENT MODELS 6023A and 6028A Load Transient Recovery Waveform

6023A

6028A

Figure 2-7. Load Transient Recovery Waveform

Temperature Coefficient. (6023A) Temperature coefficient (TC) is the change in output voltage for each °C change in ambient temperature with constant ac line voltage, constant output voltage setting and constant load resistance. Measure temperature coefficient by placing the unit in an oven, varying the temperature over a range within the unit's operating temperature range, and measuring the change in output voltage. Use a large, forced air oven for even temperature distribution. Leave the unit at each temperature measurement for half hour to ensure stability in the measured variable. Measure the output voltage with a stable DVM located outside the oven so voltmeter drift does not affect the measurement accuracy. To measure offset TC, repeat the procedure with output voltage set to 0.10Vdc.

Proceed as follows:

a.Connect DVM between +S and -S.

b.Place power supply in oven, and set temperature to 30°C.

c.Turn the unit's power on and turn up current setting to full output.

d.Turn up output voltage to 20Vdc as read on the DVM.

e.After 30 minutes stabilization record the temperature to the nearest 0.1°C. Record the output voltage at the DVM.

f.Set oven temperature to 50°C.

g.After 30 minutes stabilization, record the temperature to the nearest 0.1°C. Record output voltage.

h.Check that the magnitude of the output voltage change is no greater than 32mV.

Drift (Stability) (6023A). Drift is the change in output voltage beginning after a 30-minute warm-up during 8 hours operation with constant ac input line voltage, constant load resistance and constant ambient temperature. Use a DVM and record the output at intervals, or use a strip-chart recorder to provide a continuous record. Check that the DVM's or recorder's specified drift during the 8 hours will be no more than 0.001%. Place the unit in a location with constant air temperature preferably a large forced-air oven set to 30°C and verify that the ambient temperature does not change by monitoring with a thermometer near the unit. Typically the drift during 30 minute warm-up exceeds the drift during the 8-hour test. To measure offset drift, repeat the procedure with output voltage set to 0.10Vdc.

a.Connect DVM between + S and - S.

b.Turn the unit's power on and turn up current setting to full output.

c.Turn up output voltage to 20Vdc as read on the digital voltmeter.

d.After a 30 minute warmup, note reading on DVM.

e.The output voltage should not deviate more than 5mV from the reading obtained in step d over a period of 8 hours.

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