User manual

Page 64
PSI 9000 DT Series
www.elektroautomatik.de
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EA Elektro-Automatik GmbH
Helmholtzstr. 31-33 • 41747 Viersen
Germany
Fon: +49 2162 / 3785-0
Fax: +49 2162 / 16230
3.9.2.3 Possible technical complications
Operation of switching mode power supplies as a voltage source can, when applying a function to the output volt-
age, lead to damage of the output capacitors due to continuous charging/discharging which causes overheating.
Furthermore the actual voltage progression may differ from what’s expected.
3.9.3 Method of operation
In order to understand how the function generator works and how the value settings interact, the following should
be noted:
The device operates, including in function generator mode,always with the three set values U,I and P.
The selected function can be used on one of both the values U or I, the other two are then constants and have
a limiting effect. That means if, for example, a voltage of 10 V is set for the DC output, a load is connected and
a sine wave function should operate on the current with an amplitude of 20 A and offset 20 A, then the function
generator will create a sine wave progression of current between 0 A (min) and 40 A (max), which will result in an
output power between 0 W (min) and 400 W (max).The output power, however, is limited to its set value. If this
was 300 W then, in this case, the current would be limited to 30 A and, if clamped to an oscilloscope, it could be
seen as capped at 30 A and never achieve the target of 40 A.
3.9.4 Manual operation
3.9.4.1 Function selection and control
Via the touchscreen one of the functions described above can be called up,
conguredandcontrolled.Selectionandcongurationareonlypossiblewhile
the output is switched off.
► How to select a function and adjust parameters
1. Tap the touch area on the main screen.
If the menu does not appear it is because the DC output is still switched on or the touch area is locked due
to the device being possibly in remote control.
2. In the menu overview tap on the touch area and then on the desired function.
Note: this touch area is locked in R mode (adjustable resistance).
3. Depending on the choice of function there follows a request to which value the function generator is going
to be applied: or .
4. Adjust the parameters as you desire, like offset, amplitude and frequency for a sine wave, for example.
5. Do not forget to adjust the overall limits of voltage, current and power, which you can access with touch
area .
When entering function generator mode, those limits are reset to safe values, which can prevent
the function from working at all. For example, if you apply the selected function to the output
current, then the overall current limit should not interfere and should at least be as high as
offset + amplitude.
Setting the various functions is described below. After setting it up, the function can be loaded.