Et system LAB-HP/E 10KW, Manual

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Appendix
ET System electronic GmbH 33
Pratical Rippel Measurment.
ET-System measured the ripple with the test setup how is show at picture 5. Tow high voltage capacitor in serie with a
10k Ohm resistor is use to measured only the AC-Component of the output voltage of the power supply. The circuit
have tow output. Output 1 have a measurment bandwith of 20MHz and output 2 have a bandwith of 300kHz. This
rippel circuit was build at the labortory and was tuned by using a frequency analyser (Bode 100). Also the used 1:1
Oscilloscope probe was during the tuning procedure connectet to the rippel measurment setup to elemenate the
influence of the probe to the measurment bandwith.
Picture 6 show the result of frequency analyses of the tuning measurement. Point 1 shows the 3dB point of the
300kHz output. Point 2 show the 20MHz point.
The bode plot show that the transfer function of this circuit is very linear. This allowed making a clean and real
measurement of the output ripple of a power supply also at high voltage devices.
1 2
-100
-80
-60
-40
-20
0
20
10
2
10
3
10
4
10
5
10
6
10
7
T
R
1/
dB
f/Hz
TR1: Mag(Gain) Memory 1 : Mag(Gain)
Memory 2 : Mag(Gain)