I am reading it all, even if a lot of it is over my paygrade
My method is try to first dazzle them with brilliance. If that fails, try to baffle them with BS. One or the other most times works
Jan
But for email there is a good reason Baudot code - Wikipedia
Curious way to show bit values with + and - instead of 1 and 0. Imagine doing boolean algebra with +'ses and -'nusses.
Jan
My method is try to first dazzle them with brilliance. If that fails, try to baffle them with BS. One or the other most times works
Jan
Oh yes, one or the other is always a get out of jail card to hold in reserve. Thanks for that Jan.
I found (and still find) that so much knowledge is assumed when dealing with LT. What should be fairly simple operations can be absolutely baffling at first... and my problem is that I just don't use a lot of the functions often enough to remember how it was done. Lol, like adding a 3rd party model.
I stumbled through adding a Pspice opamp model here (post #146) but if you asked me to do it now then I would have to refer back to the tutorial. Such is life though
Adding a Pspice 3rd party model
If you jump in the time machine you can find all sorts of interesting things. Front lines of the simulator wars in 2005:
SuperSpice and new component | Electronics Forums
Both the LTspice and Superspice creators participate. I remember there was another thread somewhere that they were going back and forth about simulator design problems, and it was not all agreement. I can't find that thread though.
Here is the LTSpice announcement:
Google Groups
SuperSpice and new component | Electronics Forums
Both the LTspice and Superspice creators participate. I remember there was another thread somewhere that they were going back and forth about simulator design problems, and it was not all agreement. I can't find that thread though.
Here is the LTSpice announcement:
Google Groups
Thanks for that Jan.
I found (and still find) that so much knowledge is assumed when dealing with LT. What should be fairly simple operations can be absolutely baffling at first... and my problem is that I just don't use a lot of the functions often enough to remember how it was done. Lol, like adding a 3rd party model.
I stumbled through adding a Pspice opamp model here (post #146) but if you asked me to do it now then I would have to refer back to the tutorial. Such is life though
Adding a Pspice 3rd party model
Yes. Only so many hours in a day.
Right now I am trying to figure out if there is something like a .trace or .plot command where I can enter a function or equation that is then automagically plotted.
I don't think there is though.
Jan
Ahhhhh, here it is:
Google Groups
Mike's decisions make more sense IMO. And while he does sometimes sound like a braggart, you have to take into consideration that he's telling the truth. If it were anyone but him, it would just be taken as a statement.
Google Groups
Mike's decisions make more sense IMO. And while he does sometimes sound like a braggart, you have to take into consideration that he's telling the truth. If it were anyone but him, it would just be taken as a statement.
This made me laugh (I doubt comprehensive benchmarks exist). The roots in the original Berkeley SPICE (like the virtual punch card SPICE deck interface) are there.
I disagree on the case in point floating nodes are problematic especially if you use ideal sources anywhere. Asking the user to check their circuit and intervene if needed is the right thing to do.
Punting the SPICE deck model and using a command line interface with macros makes it easy to add a Matlab-like set of commands mixing in user defines variables with waveforms.
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For me the most user-friendly way to approach this would be both a warning and a solution:
- this node is floating and will give you issues when you build it that way;
- but here's your .ac solution.
Best of both worlds.
Jan
I understand the point, in fact I went to our guys 30yr. ago and asked them to add a complete save/restore command of all node voltages and currents so I didn't have to wait 10min for a DC convergence every time I tuned a capacitor in the compensation network. They didn't realize that changing reactances can't effect the DC values.
Floating nodes will break some sim eventually why not fix it?
IIRC LTspice does warn the user, if you look in the error log.
Also changing reactances can and does affect the DC solution found by the simulator, because those time constants must often be taken into account in order to arrive at the correct operating point.
LTspice does have a savebias feature where you can save the operating point and use it in the next simulation.
Also changing reactances can and does affect the DC solution found by the simulator, because those time constants must often be taken into account in order to arrive at the correct operating point.
LTspice does have a savebias feature where you can save the operating point and use it in the next simulation.
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I do find it strange that LTSpice wants to recompute the operating point for every step in a simulation where only a capacitor is changed. It's a conservative decision I suppose in case the capacitor actually does change the operating point, but it causes simulations to take much longer than they need to.
One problem with saving the operating point is that if you create or delete any nodes it becomes useless. So it's not necessarily something you want to be using constantly.
Some of the options here might be useful in tuning the DC solution behavior:
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Yeah that's probably the more sensible way. You need to fix it sometimes might as well do it right now.
Not tuning a few pF at a time or if you run DC convergence to full resolution which was the case here. In fact It worked like a charm always and became a permanent feature. Remember this was 30+ years ago and Berkeley SPICE still used the original setting of nodes by hand as a sort of guessing game to speed convergence. It seemed obvious to me considering memory concerns were no longer necessary.
EDIT - There might be unnecessary discussion here, what we had to work with was fairly primitive (multi-user VAX) many of the simulation modes you might assume were available were not. Trimming capacitors involved editing the deck and restarting it from the beginning.
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Is this a solution when using big caps into a supply to measure ripple supression of amp?. Because that way I have to set a big value and costs a lot of time, if this is just once and save it
for the next time it is nice.