It's too bad then that LTS doesnt work in time domain for noise analysis, but maybe they have a separate noise source we can put into the circuit? Or maybe they allow a "rand" function in one of the function sources.
That's what i used in the past, but not for LT Spice yet.

LATER:
Ok rand works but will take a little fussing with to get a decent 'noise' signal.

I found this on electronics.stackexchange.com, so we may be in luck.

 

HI everyone! HP wanted me to let you all know she saw the thread even though she couldn't login cuz hotel's network doesn't allow forms whatever that means?
Anyhow she's very happy and grateful for your responses and says she'll reply to all of them when she's back!

 

I found this on electronics.stackexchange.com, so we may be in luck.

Hi,

Oh yes that looks very good. Looks like some other stuff about LT Spice there too. I'll have to take a look and see what else i can find that might be interesting.

 

HI everyone! HP wanted me to let you all know she saw the thread even though she couldn't login cuz hotel's network doesn't allow forms whatever that means?
Anyhow she's very happy and grateful for your responses and says she'll reply to all of them when she's back!

Hi,

I was wondering why we havent heard from HP in a while. What is 'she' on vacation or something? Maybe in Rio

 

See

 

Hi,

I was wondering why we havent heard from HP in a while. What is 'she' on vacation or something? Maybe in Rio

Sort of but in Ont and Mn not Rio! Really she's having way too much fun testing salvaged tubes and larking about at EFA But she'll be back after holiday weekend at very latest and hopefully on here during weekend when she's at EFA instead of hotel with the goofy wifi search engine restrictions

PS

'she'

MrAl You don't have to be careful about personal pronoun cuz she's resigned to fact everyone knows she's a she and cuz she's cisgender and straight and all that she's cool with correct pronoun. It was just that she has a _need to know policy_ regarding personal info on web but I messed that one up for her So whats done is done!

 

Sort of but in Ont and Mn not Rio! Really she's having way too much fun testing salvaged tubes and larking about at EFA But she'll be back after holiday weekend at very latest and hopefully on here during weekend when she's at EFA instead of hotel with the goofy wifi search engine restrictions

PS

MrAl You don't have to be careful about personal pronoun cuz she's resigned to fact everyone knows she's a she and cuz she's cisgender and straight and all that she's cool with correct pronoun. It was just that she has a _need to know policy_ regarding personal info on web but I messed that one up for her So whats done is done!

Hi,

Well thanks for the update, and the confirmation there.
What is EFA though?

 

What is EFA though?

Sry for that unexpanded abbreviations are like a personality disorder with me!

So EFA means Encampment Forest Association which is retreat near Two Harbors Mn I like to tease @Hypatia's Protege by comparing it to Southfork Hunting And Fishing Club of Johnstown fame! But to be fair EFA doesn't have a leaky dam and even if they did it could only flood the lake which is already the size of S. Carolina so big non event would be like song:

 

Sort of but in Ont and Mn not Rio! Really she's having way too much fun testing salvaged tubes and larking about at EFA But she'll be back after holiday weekend at very latest and hopefully on here during weekend when she's at EFA instead of hotel with the goofy wifi search engine restrictions

Sry for that unexpanded abbreviations are like a personality disorder with me!

So EFA means Encampment Forest Association which is retreat near Two Harbors Mn I like to tease @Hypatia's Protege by comparing it to Southfork Hunting And Fishing Club of Johnstown fame! But to be fair EFA doesn't have a leaky dam and even if they did it could only flood the lake which is already the size of S. Carolina so big non event would be like song:

Hey, @Aleph(0) -- While you're at it -- don't forget to hand out my Social Security Number, Banking info and geographical coordinates!

 

Many, many thanks to all respondents! -- Please know that I'm carefully reviewing the thread (and heeding advice) --- I'll be in touch

With effusive gratitude!
HP

 

Hey, @Aleph(0) -- While you're at it -- don't forget to hand out my Social Security Number, Banking info and geographical coordinates!

HP I would have but I forgot your credit card numbers and blood type

 

The latter values were -75.58909 kV and 74.589351 kV

Interesting? As per the image and '.asc' files attached to my OP, the simulation results closely 'jibe with' real world circuit performance (CIP ≈ ±50kV) --- How did you manage the increased EMF?
Was it a mere matter of increasing the converter input EMF and/or unloading the output? --- Or did you modify the oscillator in some manner?

Do you get similar results with very high enlargements?

Correct - Moreover, under sufficient 'magnification', plots of |Ea| and |Ek| are indeed distinct

You might try fiddling with the RELTOL option a bit to see if you can improve results.

At present my skill with LtSpice is limited to circuit entry via the schematic editor Perhaps that's part and parcel of my trouble?

SPICE only simulates component tolerances by performing multiple simulation runs, each with different component values according to your tolerance specifications, in a Monte Carlo analysis.

Thanks for that!

HP one thing's for sure that precision is even out of your Keysight probes league so there's no checking up on simulation!

Granting even 'magic probes', component tolerances, slight temperature differential, etc. would preclude measurement to such precision...

Not identical. D1 D2 / D3 D4 are flipped.

Nonetheless, inasmuch as the secondaries are isolated, the circuits are electrically identical... FWIW similar anomalies occur with an 'untapped' load resistor...

But blaming spice is much easier.

Not at all! -- I've no doubt that the discrepancy owes to my own lack of proficiency with the simulator

You are looking at a single point in time, 10 mSec after simulation startup. Let it run longer to get to see if the error shrinks. Expecting a stable system in 10 mSec on a 50kV system doesn't happen in real life, why should it happen in a simulation?

The simulation seems to 'settle' by 10 ms howbeit I can certainly try a longer run!

Set starting values of the components instead of letting everything start at 0V

Owing to the transistors' (model's) precisely equal gain, 'push-pull' oscillators don't simulate well sans a 'noisy' startup

There's something that looks like random noise in the waveforms. Easiest to see if you add a behavioural voltage source whose output is the sum of the two waveforms.

I noticed that also -- It appears to be 'ripple' under magnification - Although the sporadic, at times 'wild', amplitude excursions led me to believe it was a simulation artifact?



-- To be continued ASAP

 

Kind friends

Having carefully studied the contents of this thread over the course of the last few days, I've arrived at the (astounding) conclusion that anything approaching proficiency at LtSpice requires my attainment of skills beyond mere 'schematic entry'. --- Although many on-line resources are available, I'm experiencing some difficulty locating material applicable to readers well 'versed' in electronics while in need of instruction in 'advanced' use of Spice... (IOW I require "LtSpice 101" -- as opposed to "Introduction to Electronics" via elementary exercises in spice) --- Your suggestions will be greatly appreciated!!!

Many, many sincere thanks for the interest, attention and assistance manifest on this thread!

Most sincerely
HP

 

Having carefully studied the contents of this thread over the course of the last few days, I've arrived at the (astounding) conclusion that anything approaching proficiency at LtSpice requires my attainment of skills beyond mere 'schematic entry'. --- Although many on-line resources are available, I'm experiencing some difficulty locating material applicable to readers well 'versed' in electronics while in need of instruction in 'advanced' use of Spice... (IOW I require "LtSpice 101" -- as opposed to "Introduction to Electronics" via elementary exercises in spice)

Googling on the phrases, "learning ltspice", "learning spice", "learning pspice" and "spice pitfalls" all produced a fair amount of potentially useful material. The National Instruments whitepaper SPICE Simulation Fundamentals seems to have a fair amount of useful information also, especially in Section 7 which discusses SPICE simulation options and how they affect simulation speed and accuracy. Although it is written to apply to NI's Multisim simulator, everything in there should apply to LTSpice as well.

But I know of nothing in print or on the Internet that could qualify as "LTSpice 101" for your purposes.

For whatever it's worth, my impression from reading your LTSpice-related posts is that much of your difficulty with LTSpice seems to come from having somewhat unrealistic expectations of its capabilities. I think that the more you can learn about how SPICE operates internally, and how the various simulation options affect performance, the better your expectations will align with reality and the less frustration you will experience overall. SPICE is imperfect, and its imperfections are legion.

 

Section 7 which discusses SPICE simulation options and how they affect simulation speed and accuracy.

Perfect - Just what I'm looking for -- Thanks!

For whatever it's worth, my impression from reading your LTSpice-related posts is that much of your difficulty with LTSpice seems to come from having somewhat unrealistic expectations of its capabilities. I think that the more you can learn about how SPICE operates internally, and how the various simulation options affect performance, the better your expectations will align with reality and the less frustration you will experience overall. SPICE is imperfect, and its imperfections are legion.

True enough! -- Once I have a 'handle' on the simulation directives/options/parameters, etc... perhaps I'll gain a better feel for the limitations --- To be clear, I neither expect nor hope for anything like perfection -- howbeit a sense (even if intuitive) of what might reasonably be trusted vs. regarded with (varying degrees) of caution would be very nice!

Very best regards and many thanks!
HP

 

...howbeit a sense (even if intuitive) of what might reasonably be trusted vs. regarded with (varying degrees) of caution would be very nice!

One thing that might help in developing that sense-- and did help in my case-- is to run simulations of circuits whose behavior you are very familiar with, and look at the differences between reality and the simulation.

Another thing you can do is "drill down" into device models-- especially op amp macromodels-- and take a close look at what characteristics are modeled and which are not. Understanding model limitations can allow much hair-pulling to be avoided.

 

One thing that might help in developing that sense-- and did help in my case-- is to run simulations of circuits whose behavior you are very familiar with, and look at the differences between reality and the simulation.

Agreed! Hence my focus upon simulation of Royer/Mazzilli oscillators/PSUs, feedback regulation schemes, high intensity ultrasound piezo drivers, etc... Oddly, simulation results most closely approaching reality tend to be attainable only via selection of less than optimal --often straight up inappropriate-- active component models

Which would seem to 'dovetail with':

Another thing you can do is "drill down" into device models-- especially op amp macromodels-- and take a close look at what characteristics are modeled and which are not. Understanding model limitations can allow much hair-pulling to be avoided.

Absolutely! [Learning] interpretation and, indeed, creation/'tailoring' of device models is a top priority! -- 'Tis indeed 'nice to know what's going on'

Very best regards - and, again, many thanks!
HP