SPICE-Simulation using LTspice IV

6.5. Two Pulse Rectifier with real Transformer
Here we need at first something new: a line transformer with 2 secondary windings.
Step 1:
We open our well-known file „xformer_01.lib“ to modify it.
Let the turn ratio be again 20:1 and add an additional
secondary winding, also with 2.5mH. Write the necessary
lines in your file (...they are a simple copy of secondary
winding 1, but be aware of the node names...)
Reduce the flux leakage inductances and the copper
resistors to get an ideal transformer, but don’t set them to
zero.
Please do not forget:
No we have 3 windings which are magnetally coupled.
You have to enter a new coupling information
K Lpri1 Lsec1 Lsec2 0.999
At last save the file as „xformer_02.lib“ in the “sub“-
folder of the library.
Step 2:
Also a new symbol is necessary and must be created -- see
Chapter 6.2.2.
But do not forget:
Warning:
The line for Value2 MUSS NEVER BE
EMPTY....otherwise you can get a cryptic
error message and / or a simulation
abort...
Step 3:
Draw the circuit using the new transformer and two diodes of the 1N4007-type. Then simulate and compare the
result with the following page:
42