46
so a single LED Rd = Rd=
3.52−3.35
0.4−0.3
=1.7 Ω
From formula 3.3, Rf= Rd×
Io
Vo
=1.7×
0.35
3.44
=0.173
4.
After the setting is completed, press the key
to back to the test interface, press the
key
to start testing.
3.10 SWEEP dynamic frequency conversion scanning
The E-load provides a variable frequency sweep function to capture the Vp+ and Vp- of
the power supply under test in the most severe conditions. Be similar to the DYNA mode,
the E-load switch repeatedly between the two loads according to the preset current rise
rate and current drop rate, and the difference is that the duration of each current level will
be determined by the sweep frequency and duty cycle (Duty). At the same time, the
scanning frequency will also gradually increase from the starting scanning frequency
(Fstart) to the cutting frequency (Fend), the step frequency is (Fstep), and the scanning
duration of each frequency point is single frequency time (Dwell) ,during the scanning
process, the input voltage will overshoot and fall accompanied by the transient of the
current. The E-load will display the voltage peak (Vp+) during overshoot and the voltage
valley (Vp-) at the time of the fall, and finally show the maximum of Vp+ ,the minimum of
Vp-, and the frequency point at which each occurs.
Press the key
on the front panel of the E-load and select the SWEEP function to
switch the test mode.
ET System electronic GmbH
