Text and symbols changing sizes indicates there may be other problems of which you are not aware. The inability to find the subcircuit for a symbol is indicative of a broken link between the symbol called out in the schematic, the first occurrence of that symbol name in your directory tree, and the name of the subcircuit called out by the symbol.Need a transformer model that allows for turns entry. Also, for some reason some of my text and symbols have taken on different sizes? It seems my Voltage models have shrunk? For example...
View attachment 263193
A quick way is to calculate pri/sec inductance using "the square of the turns ratio" method.Need a transformer model that allows for turns entry. Also, for some reason some of my text and symbols have taken on different sizes? It seems my Voltage models have shrunk? For example...
View attachment 263193
This is something new that I have not seen before in my studies. I understood the video that DeltaPrime linked to using the square root of the inductance to determine the turns ratio. Which is obviously the reverse method of getting inductance from turns. How does that then get adjusted for frequency? What I am presently working with is all 60Hz power supplies at various voltages.A quick way is to calculate pri/sec inductance using "the square of the turns ratio" method.
Then adjust the values for frequency.
Spice transformers can get complex in a hurry. But to keep it simple, once you have the correct inductance values, adjust the inductance values, while keeping the ratio constant, so that the reactance satisfies the (current transfer) load requirement.This is something new that I have not seen before in my studies. I understood the video that DeltaPrime linked to using the square root of the inductance to determine the turns ratio. Which is obviously the reverse method of getting inductance from turns. How does that then get adjusted for frequency? What I am presently working with is all 60Hz power supplies at various voltages.
As you know the inductive reactance is a linear function of the frequency. As the frequency goes up you want to make the inductance smaller so that the inductive reactance does not get too large. You can easily use a spreadsheet to compute the reactance for a fixed frequency. Like this:This is something new that I have not seen before in my studies. I understood the video that DeltaPrime linked to using the square root of the inductance to determine the turns ratio. Which is obviously the reverse method of getting inductance from turns. How does that then get adjusted for frequency? What I am presently working with is all 60Hz power supplies at various voltages.
Inductive Reactance | | | |
Frequency | 60 | Hz. | |
| | | |
Inductance | | Reactance | |
10.00E-06 | | 0.00376991118430775 | Ω |
100.00E-06 | | 0.0376991118430775 | Ω |
1.00E-03 | | 0.376991118430775 | Ω |
10.00E-03 | | 3.76991118430775 | Ω |
100.00E-03 | | 37.6991118430775 | Ω |
| | | |
Reactance is not of much concern at low frequency | | | |
| | | |
Frequency | 100.00E+03 | Hz. | |
| | | |
Inductance | | Reactance | |
10.00E-06 | | 6.28318530717959 | Ω |
100.00E-06 | | 62.8318530717959 | Ω |
1.00E-03 | | 628.318530717959 | Ω |
10.00E-03 | | 6283.18530717959 | Ω |
100.00E-03 | | 62831.8530717959 | Ω |
| | | |
Even 1mH has significant reactance @ 100kHz | | | |
If you're using inductors in an AC transformer, there is still inductive reactance.OK, what I am doing is using the ideal model for the XFMR so the reactive inductance does not come into play. One of these days I will get around to finishing Malvino's Resistive and Reactive Circuits...
The model you posted originally, is for an ideal "DC-DC Transformer". This part does not exist in reality. It is used to investigate the behavior of DC-DC converters. I believe it is a serious mistake to use it in conjunction with the circuit in your original post. Just use the coupled inductors. You will avoid getting tricked by the results that you observe.OK, what I am doing is using the ideal model for the XFMR so the reactive inductance does not come into play. One of these days I will get around to finishing Malvino's Resistive and Reactive Circuits...
That was just noodling around with what was available in my libraries. Think I have the answer to what I am currently working on from the old LTS4 video on the AD site.The model you posted originally
Nothing wrong with that, but it helps to have some context when that is available. I did not come by all these examples that I've posted overnight.That was just noodling around with what was available in my libraries. Think I have the answer to what I am currently working on from the old LTS4 video on the AD site.