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EPS Stromversorgung GmbH
Alter Postweg 101 • 86159 Augsburg
Germany
Fon: +49 821 / 570451-0
Fax: +49 821 / 570451-25
www.eps-germany.de
PSI 10000 4U Serie
3.10.2.3
Resolution
Amplitudes generated by the arbitrary generator have an effective resolution of approx. 52428 steps. If the am
-
plitude is very low and the time long, the device would generate less steps and set multiple identical values after
another, generating a staircase effect. It’s furthermore not possible to generate every possible combination of time
and a varying amplitude (slope).
3.10.2.4
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.
3.10.2.5
Minimum slope / maximum ramp time
When using a rising or falling offset (i.e. DC part) at functions like ramp, trapezoid, triangle and even sine wave,
a minimum slope, calculated from the rated values of voltage or current, is required or else the adjusted settings
would be neglected by the device. Calculating the minimum slope can help to determine if a certain ramp over
time can be achieved by the device or not. Example: model PSI 10080-1000 is going to be used, with 80 V and
1000 A rating.
Formula: minimum slope = 0.000725 * rated value / s
. For the example model it results in ΔU/
Δt of 58 mV/s and ΔI/Δt of 725 mA/s. The maximum time which can be achieved with the minimum slope always
calculates as approximately 1379 seconds according to formula
t
Max
= rated value / min. slope.
3.10.3
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 always works with the three set values U, I and P, also in function generator mode.
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 30 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 300 A and offset 400 A, then the function
generator will create a sine wave progression of current between 100 A (min) and 700 A (max), which will result in
an output power between 3000 W (min) and 21000 W (max).The output power, however, is limited to its set value.
If this were 18000 W then, in this case, the current would be limited to 600 A and, if clamped to an oscilloscope, it
would be seen to be truncated at 600 A and never reach the peak of 700 A.
Master-slave systems have further characteristics which have to be considered:
At the end of the configuration of every standard function you are requested to set up global
set values, the so-called “U/I/P limits”. These limits are transferred to all slave units of mas
-
ter-slave systems. It’s recommended to carefully configure them so the MS system can work
as expected and the slaves wouldn’t impact the function run in a negative way.
