SPICE-Simulation using LTspice IV

Step 6:
At last make visible all important informations for the user.
Start with „Edit“ and „Attributes“, but now choose „Attribut
Window“. When clicking on „value“, then you get the description
„2_wind_XFRM“ at your cursor and you can place it over the
symbol.
Then repeat the procedure but now choose „SpiceModel“ =
xformer_01.lib and place it below the symbol. The work is done!
Step 7:
Save the complete symbol.
Open „File“ and „Save as“ and the correct path starting at „SwCADIII“ and „lib“ just down to the folder „sym“
(= symbols). There create a new folder named „Xformers“ and save this new part as „xformer_01.asy“.
6.3. One Pulse Rectifier with Transformer
Now let us test a circuit with line transformer, one pulse-rectifier and output capacitor.
Task:
Test a power supply consisting of a line transformer, rectifier, load resistor R1 = 1k and load capacitor
C1 = 100µF. Line input voltage is 230Vrms / 50 Hz, the turn ratio of the transformer is 20:1. Simulate in the
time domain from 0...200ms.
Solution:
Most of the necessary parts are
already known from the last
example. Fetch and place them,
wire and enter the correct part
values including the properties of
the voltage source and add the
command for the simulation from 0
to 200ms in the time domain.
But now we need the line
transformer of the last chapter.
Fetch and place the part.
Then we look for the necessary
transformer property entries.
You cannot enter the turn ratio N1/N2 in a direct form, so you need the following equation for the inductances:
L
L
primary
secondary
N
=
N
1
2
2
Let us apply a value of 1Henry for the primary main inductance (….ideal transformer…) and calculate the
secondary main inductance for a turn ratio of 20:1 in the following manner:
L
=
( 20)
1H
=
400
primary
L
secondary
=
2
2.5mH
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