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EPS Stromversorgung GmbH
Alter Postweg 101 • 86159 Augsburg
Germany
PSI 9000 3U Series
Fon: +49 821 / 570451-0
Fax: +49 821 / 570451-25
3.9.8 Trapezoidal function
The following parameters can be configured for a trapezoidal curve function:
Value
Range
Description
I(A), U(A)
0...(Nominal value - (Off)) of U, I
A = Amplitude of the signal to be generated
I(Off), U(Off) 0...(Nominal value - (A)) of U, I
Off = Offset, based on the foot of the trapezium
t1
0.1 ms...36000 s
Time for the positive slope of the trapezoidal wave signal.
t2
0.1 ms...36000 s
Time for the top value of the trapezoidal wave signal.
t3
0.1 ms...36000 s
Time for the negative slope of the trapezoidal wave signal.
t4
0.1 ms...36000 s
Time for the base value (offset) of the trapezoidal wave signal
Schematic diagram:
Application and result:
O
ffse
t
t
A
A
m
plit
ud
e
t1
t2
t3
t4
Here a trapezoidal signal can be applied to a set value
of U or I. The slopes of the trapezium can be different
by setting different times for gain and decay.
The periodic duration and repetition frequency are the
result of four time elements. With suitable settings the
trapezium can be deformed to a triangular or rectangular
wave. It has, therefore, universal use.
3.9.9 DIN 40839 function
This function is based on the curve defined in DIN 40839 / EN ISO 7637 (test impulse 4), and is only applicable
to voltage. It shall replicate the progress of automobile battery voltage during engine starting. The curve is divided
into 5 sequences (see diagram below) which each have the same parameters. The standard values from the DIN
are set already as default values for the five sequences.
The following parameters can be configured for the DIN40839 function:
Value
Range
Seq Description
Ustart
0...Nominal value of U
1-5
Start voltage of the ramp
Uend
0...Nominal value of U
1-5
End voltage of the ramp
Seq.time
0.1 ms...36000 s
1-5
Time of the ramp
Seq.cycles ∞ or 1...999
-
Number of repetitions of the entire curve
Time t1
0.1 ms...36000 s
-
Time after cycle before repetition (cycle <> 1)
Schematic diagram:
Application and result:
t
A
U s
ta
rt
1
2
3
4
5
t1
Sequences
The function is not suitable for standalone operation of a
power supply, but optimal for power supply in conjunction
with an electronic load, for example one from ELR 9000
series. The load acts as a sink for the rapid fall of the
output voltage of the power supply enabling the output
voltage progress to follow the DIN curve.
The curve conforms to test impulse 4 of the DIN. With
suitable settings, other test impulses can be simulated.
If the curve in sequence 4 should be a sine wave, then
these 5 sequences have to be transferred to the arbitrary
generator.
