Fun And Games With Spice

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Mike H
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#106

Post by Mike H »

Don't know if anyone's actually done that with a 10M45S but can't see why not :?:
 
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Mike H
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#107

Post by Mike H »

Here are the files if anyone else wants a play
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10m45s.zip
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Nick
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#108

Post by Nick »

Cool I will have a play tonight. I use a number of the things now, they make great cathode follower loads, and I want to play with them as a shunt regulator with a valve on top to do the hard work.
Whenever an honest man discovers that he's mistaken, he will either cease to be mistaken or he will cease to be honest.
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Mike H
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#109

Post by Mike H »

If you want or need to change the slope (depending how well it matches a real one, though it can't be that far off), just tweak the '500' number in the formula for G2

BTW re the dynamic resistance, I did a quick calc removing the parallel 470k from 320k and got about 1 Megohms :?:
 
"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
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Mike H
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#110

Post by Mike H »

I found a LTspice model for a speaker in a ported box on the Internet.

Just mostly by Thiele/Small parameters in the first .param line.

If need more complete numbers to fill it in use this web page:

http://www.micka.de/org/en/

Run the .ac analysis, the current through C1 represents SPL.

Run .tran for step response (10 Hz square wave), again looking at C1 current.

To get the impedance against frequency, run the .ac again.

In the trace window, add a new trace (Plot Settings menu) as V(vin)/I(Re). Set the Y axis to linear, and adjust the Ohms scaling as required. Can be quite revealing!

The next logical step might be make a subckt model of the loudspeaker parts to use as the load for your amplifier simulations.
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Loudspeaker Enclosure model.zip
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"No matter how fast light travels it finds that the darkness has always got there first, and is waiting for it."
Suusi
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#111 Re: Fun And Games With Spice

Post by Suusi »

Hi Mike H

Just recently found the suppressor grid play you did with the EF86 on Duncan Morno's models (I think) Nice work. Thanks :)

How far did you get with extending this to Norman Koren's work?

I have massively extended the Koren tube library Including luftwaffe valves because I like simulating WW2 German avionics in LTspice. Unfortunately I cannot attach it as the system wont let me. :cry:

I use a modified version of Norman Korens's matlab program to extract the coefficients for the models and digitizit to extract the data from the data sheets.
Electronics engineer and programmer from Harpenden UK
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