Heinzinger electronic GmbH
Phone: +49 (0) 8031 2458 0
www.heinzinger.com
Anton-Jakob-Str. 4, 83026 Rosenheim
Fax: + 49 (0) 8031 2458 58
Germany
Page 82
ERS COMPACT
3.11.2.3
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).
3.11.2.4
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.
3.11.2.5
Minimum slope / maximum ramp time
When using a rising or falling offset (i.e. DC part) in functions like ramp, trapezoid and triangle, 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 ERSC 10200-420 is going to be used, with 200 V and 420 A rating.
Formula:
minimum slope = 0.000725 * rated value / s
. For the example model it results in ΔU/Δt of 145 mV/s and ΔI/Δt of
304 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.
3.11.3
Method of operation
In order to understand how the function generator works and how the values 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 values, U or I, the other two are then constants and have a
limiting effect. That means if, for example, a voltage of 100 V is set in source mode for the DC output, a load is
connected and a sine wave function should operate on the current with an amplitude of 80 A and offset 80 A, then
the function generator will create a sine wave progression of current between 0 A (min) and 160 A (max), which will
result in an output power between 0 W (min) and 16000 W (max). But in case the output power would be limited to,
for instance, 12000 W the current would be limited to 120 A and, if clamped to an oscilloscope, the current could
be viewed being truncated at 120 A and never reach the peak of 160 A.
For an even better understanding how the device works in dynamic operation read following:
•
The device also has an integrated electronic load, here called “sink”, which is supposed to dis
-
charge the capacities on the DC terminal of the device when running dynamic voltage changes
in source mode, i.e higher voltage to lower voltage. This requires a certain current and thus
power setting, which can and should be adjusted for almost every function described below
(parameters “I Sink” and “P Sink”). For safety reasons, the current value “I Sink” is always set
to 0 after selecting a function for configuration, deactivating sink mode.
•
The sink current, adjustable as “I Sink”, when being set to > 0 would load an external source,
perhaps also discharge capacities in this source and thus this current setting has to be chosen
carefully, because it also affects the necessary cross section of cables. Recommendation: set
“I Sink“ to at least I
Peak
of the resulting curve or higher.
Master-slave systems have further characteristics which have to be considered:
At the end of the configuration, after the function has been loaded and the screen shows the
main view of the function generator, there are adjustable set values, the so-called “U/I/P lim
-
its”. These limits are transferred to all slave units of master-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.