Step 4. Program the power system to the settings indicated in the in the test record form for theappropriate model under “CV Ripple and Noise” and enable the output. Let the oscilloscope run for afew seconds to generate enough measurement points. On the Keysight Infiniium scope, the maximumpeak-to-peak voltage measurement is indicated at the bottom of the screen on the right side. Dividethis value by 10 to get the CV peak-to-peak noise measurement. The result should not exceed thepeak-to-peak limits in the test record form for the appropriate model under “CV Ripple and Noise,peak-to-peak”.If the measurement contains any question marks, clear the measurement and tryagain. This means that some of the scope data received was questionable.Step 5. Disconnect the oscilloscope and connect an rms voltmeter in its place. Do not disconnect the50 ohm termination. Divide the reading of the rms voltmeter by 10. The result should not exceed therms limits in the test record form for the appropriate model under “CV Ripple and Noise, rms”.Transient Recovery TimeThis test measures the time for the output voltage to recover to within the specified value following a50% change in the load current.Step 1. Turn off the power supply and connect an oscilloscope across the sense terminals (see TestSetup A). Connect an electronic load to the output terminals.Step 2. Turn on the power supply and program the instrument settings as described in the test recordform under “Transient Response”.Step 3. Set the electronic load to operate in constant current mode. Program its load current to thelower current value indicated in the test record form under “Transient Response”.Step 4. Set the electronic load's transient generator frequency to 100 Hz and its duty cycle to 50%.Step 5. Program the load's transient current level to the higher current value indicated in the testrecord form under “Transient Response”, and turn the transient generator on.Step 6. Adjust the oscilloscope for a waveform similar to that shown in the following figure.Step 7. The output voltage should return to within the specified voltage at the specified time followingthe 50% load change. Check both loading and unloading transients by triggering on the positive andnegative slope. Record the voltage at time “t” in the performance test record form under “TransientResponse”.Keysight N6900/N7900 Series Operating and Service Guide 3137 Verification and Calibration
