Re: [Qucs-help] Ideal Transformer

 Re: [Qucs-help] Ideal Transformer From: Andy Fierman - 2011-06-27 13:31:25 ```Oops. My misunderstanding. If K=1 is invalid then an ideal AC transformer cannot be made using the mutual inductors. Hence, isn't that a case for keeping the ideal DC transformer? Then an ideal AC transformer can be realised by putting an inductor across the primary. Even so this is not a complete solution because any dc resistance added to this inductor would then generate a DC output from the secondary for a DC input to the primary. Would a preferred solution not be to allow the range for K to =+1 and -1? I know QUCS is not SPICE but most other simulators allow k=+/-1. Cheers,          Andy. signality.co.uk On 27 June 2011 14:13, Carsten Koegler wrote: > Hi Andy, > >> I have found on QUCS 0.0.16 that the mutual inductor model will not >> allow k=1 even though the error message when setting k=1 states that >> k=1 is valid: >> >> "checker error, value of `k' (1) is out of range `]-1,1[' in `MUT:Tr1'". >> > > The error message states, that -1 and 1 are invalid. The endpoint of the interval are excluded. > see > http://en.wikipedia.org/wiki/Interval_(mathematics) > > Carsten > ```

 Re: [Qucs-help] Ideal Transformer From: Andy Fierman - 2011-06-27 11:57:27 ```Hi, I'm new to this list too. I am using QUCS 0.015 on Debian Testing (Linux Mint LMDE 64bit) and 0.0.16 on Windows XP. I have a question about non-ideal transformers using the k coupling factor and was browsing this list when I saw this thread. I know this is about ideal transformers but I wanted to say that there are occasions where the ideal DC transformer is invaluable and I would very much hope this model is not removed! An ideal AC transformer is also required, i.e. one that has a primary inductance only and no other parasitics but this can be realised by the mutual inductors model with a coupling factor, k=1. However, this leads on to my question. I have found on QUCS 0.0.16 that the mutual inductor model will not allow k=1 even though the error message when setting k=1 states that k=1 is valid: "checker error, value of `k' (1) is out of range `]-1,1[' in `MUT:Tr1'". Can this be fixed? Should I submit a bug report or has this already been identified elsewhere? Cheers          Andy. signality.co.uk ```
 Re: [Qucs-help] Ideal Transformer From: Carsten Koegler - 2011-06-27 13:13:50 ```Hi Andy, > I have found on QUCS 0.0.16 that the mutual inductor model will not > allow k=1 even though the error message when setting k=1 states that > k=1 is valid: > > "checker error, value of `k' (1) is out of range `]-1,1[' in `MUT:Tr1'". > The error message states, that -1 and 1 are invalid. The endpoint of the interval are excluded. see http://en.wikipedia.org/wiki/Interval_(mathematics) Carsten ```
 Re: [Qucs-help] Ideal Transformer From: Andy Fierman - 2011-06-27 13:31:25 ```Oops. My misunderstanding. If K=1 is invalid then an ideal AC transformer cannot be made using the mutual inductors. Hence, isn't that a case for keeping the ideal DC transformer? Then an ideal AC transformer can be realised by putting an inductor across the primary. Even so this is not a complete solution because any dc resistance added to this inductor would then generate a DC output from the secondary for a DC input to the primary. Would a preferred solution not be to allow the range for K to =+1 and -1? I know QUCS is not SPICE but most other simulators allow k=+/-1. Cheers,          Andy. signality.co.uk On 27 June 2011 14:13, Carsten Koegler wrote: > Hi Andy, > >> I have found on QUCS 0.0.16 that the mutual inductor model will not >> allow k=1 even though the error message when setting k=1 states that >> k=1 is valid: >> >> "checker error, value of `k' (1) is out of range `]-1,1[' in `MUT:Tr1'". >> > > The error message states, that -1 and 1 are invalid. The endpoint of the interval are excluded. > see > http://en.wikipedia.org/wiki/Interval_(mathematics) > > Carsten > ```
 Re: [Qucs-help] Ideal Transformer From: Andy Fierman - 2011-06-28 09:48:23 ```Hi Ramiro, For info: I saw that you had said "In the past I was using ngspice, but I was tired of making circuit netlists by hand." If you install all of the gEDA package you can use gschem for schematic capture and export a spice netlist. You can then run this in ngspice or gnucap see: http://www.geda.seul.org/wiki/geda:faq-simulation :) Andy. signality.co.uk On 27 June 2011 14:30, Andy Fierman wrote: > Oops. My misunderstanding. > > If K=1 is invalid then an ideal AC transformer cannot be made using > the mutual inductors. Hence, isn't that a case for keeping the ideal > DC transformer? Then an ideal AC transformer can be realised by > putting an inductor across the primary. > > Even so this is not a complete solution because any dc resistance > added to this inductor would then generate a DC output from the > secondary for a DC input to the primary. > > Would a preferred solution not be to allow the range for K to =+1 and -1? > > I know QUCS is not SPICE but most other simulators allow k=+/-1. > > Cheers, > >          Andy. > > signality.co.uk > > > > > On 27 June 2011 14:13, Carsten Koegler wrote: >> Hi Andy, >> >>> I have found on QUCS 0.0.16 that the mutual inductor model will not >>> allow k=1 even though the error message when setting k=1 states that >>> k=1 is valid: >>> >>> "checker error, value of `k' (1) is out of range `]-1,1[' in `MUT:Tr1'". >>> >> >> The error message states, that -1 and 1 are invalid. The endpoint of the interval are excluded. >> see >> http://en.wikipedia.org/wiki/Interval_(mathematics) >> >> Carsten >> > ```