Version 9 gives different result than version 8
I have a design which had been created in PIXls version 8 (attached file: TNY4 24V 19W PQ2020 ver 8.pixls).
I then opened it in PIXls version 9 (attached file: TNY4 24V 19W PQ2020 ver 9.pixls), and it gave different results.
Specifically, in the old version it specified a nominal inductance of 969 uH, and in version 9 it specifies a nominal inductance of 872 uH.
I notice that 872 uH, which is the nominal inductance in version 9, is the same value as the minimum inductance in version 8 (nominal 969, to ensure a minimum of 872).
Which is correct?
a) Is version 8 reporting what should be the nominal value as the minimum - and reporting a nominal inductance 10% above that?
or
b) Is version 9 reporting what should be the minimum value as the nominal - and reporting a minimum inductance 10% below that?
Comments
There is another problem related to this.
If you open the attached "TNY4 24V 19W PQ2020 ver 8.pixls" using version 8, in the PIXls Designer tab it shows an LP of 969 uH (to ensure a minimum of 872 uH). In the Transformer Parameters tab, it reports an LP of 872 uH (which is the minimum LP - although not labled as such).
If you now open the same file using version 9 - and select browsing-only mode, in the PIXls Designer tab it shows an LP of 969 uH (to ensure a minimum of 872 uH) - just like it does when opened using version 8. However, in the Transformer Parameters tab, it now reports an LPmin of 788 uH - which is approximately 10% less than the minimum LP reported in the PIXls Designer tab.
Let me look into this.
My first feeling is that the transformer construction tab calculated 10% lower (based on tolerance) than the new 872 uH value...
Thanks for bringing to our attention.
In Version 8 thespreadsheet was conservative to make sure we did not underdeliver power. We did not take into account effieicny and the Z factor. Version 8 uses a statis 20% increase in the value of LP to cover for effieicny loss.
IN versiuon 9.0 we incorporate efficiency and Z factor into the LP calculation. Version 9 is more accurate (if you enter effieicny and Z factor appropriately).