What is SPICE

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IslandPink
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#196

Post by IslandPink »

Thanks Mike .
It would therefore help if there was a comment in 'resistor' and 'capacitor' pages to look also under 'Introduction/General structure and conventions' !

Other thread :
http://www.audio-talk.co.uk/phpBB2/view ... &start=105
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#197

Post by Mike H »

Ah right OK.
 
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#198

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When I plot frequency scans of things like AC current on different components, the curves for the value (mA ) and the phase (deg) are coming out as solid lines in both cases. How do I get the phase line to be dotted, so I can see what's going on more easily ?
Not been able to fix this so far, after about 30 mins of fiddling and searching with google .
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#199

Post by Mike H »

Can you show us what the plots display looks like?

Menu: Plot Settings > Reset Colors ?
 
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#200

Post by IslandPink »

Here we go :
(Display colour only changes the colours of the lines ; I also expected it to have things like dashed or solid or dotted line for the phase plots, too ) .
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Nick
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#201

Post by Nick »

Looking at that the phase is dotted, I think your display is having problems resolving it. More viable at the LF end.
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#202

Post by IslandPink »

Actually you're right - well spotted .
If the window is maximised on Spice it's just about visible.
It actually looks clearer in the .jpg I created to throw up on this thread, weirdly .
I wish I could make it a bit more obviously dashed in Spice though .
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#203

Post by Mike H »

Oh yes I see, it is doing it, just not resolved very well.
 
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#204

Post by slowmotion »

I finally read this thread, downloaded LTspice and followed the instructions
and tried out the simulations. Thanks to all!
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#205

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It's a very cool thing , a great back-up to the real building .
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#206 Re: What is SPICE

Post by Max N »

Hi, wasn't sure of the best place to ask this.....
I'm a complete novice at LTSpice. First of all, many thanks to everyone who has posted helpful tips in this and other threads.
I've drafted a PP 6B4G (well actually 2A3) output stage and got it running with resistor loading. I'm now trying to model a push-pull OPT, I have a figure for the primary inductance - should I just put half of this figure for each primary winding?
Is this of interest to anyone else? I could post the file here when it's done (might need a bit of help)
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#207 Re: What is SPICE

Post by Max N »

For reference, I am trying to model this transformer
http://www.monolithmagnetics.com/sites/ ... prelim.pdf
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#208 Re: What is SPICE

Post by Max N »

Well, I've had a go but it looks to me like the HF roll-off happens way too early, and the LF roll off isn't there at all......
LTspice PP transformer freq sweep.PNG
LTspice PP transformer freq sweep.PNG (52.16 KiB) Viewed 1063 times
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#209 Re: What is SPICE

Post by Nick »

Thats because a leakage inductance coefficient of 0.97 is defining a crap transformer. 1 is perfect, start there.

http://ltwiki.org/?title=Transformers
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#210 Re: What is SPICE

Post by Max N »

OK thanks Nick will give that a go :-)
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