What is SPICE

We all start somewhere
User avatar
IslandPink
Social Sevices have been notified
Posts: 8830
Joined: Tue May 29, 2007 7:01 pm
Location: Denbigh, N.Wales

#151

Post by IslandPink »

Cripes !
This forum has corridors and rooms full of stuff I never knew existed .
"Peridots and periwinkle, blue medallions Gilded galleons spilled across the ocean floor" ( Mitchell )
User avatar
Mike H
Amstrad Tower of Power
Posts: 19053
Joined: Sat Oct 04, 2008 5:38 pm
Location: The Fens
Contact:

#152

Post by Mike H »

I've just chucked up a somewhat modified version. One of the 'experiments' is to get a more realistic screen current for the tetrodes (i.e pentodes).
 
"Entrenched convictions cannot be changed by facts." – Dick Francis
User avatar
IslandPink
Social Sevices have been notified
Posts: 8830
Joined: Tue May 29, 2007 7:01 pm
Location: Denbigh, N.Wales

#153

Post by IslandPink »

Hi
As an aid to running Nick's model of the shunt-reg supply , I need to get some valve models into the program folder (s ).
I downloaded Mike's ( or Norman's ) 'All_Valves.txt' from the 'Stacks' section .
Now, I unzipped them, and they are at the moment all in some obscure folder several levels down in the LT Spice area.
At the moment it just consist of 5 sub-folders , in .txt form .
I can see each .txt file has a load of little scripts for each ( of many ) valves inside.

How do I get these into the right area and available for use in the program ?
"Peridots and periwinkle, blue medallions Gilded galleons spilled across the ocean floor" ( Mitchell )
User avatar
Mike H
Amstrad Tower of Power
Posts: 19053
Joined: Sat Oct 04, 2008 5:38 pm
Location: The Fens
Contact:

#154

Post by Mike H »

Open or create new schematic.

Click 'Component' button to choose a valve symbol, they're in 'Misc' section (usually).

Plonk symbol down wherever (attached to mouse, key 'Esc' to stop placing copies).

This bit had me flummoxed for ages as well!

Right mouse button click on the symbol.

This gets up the component attributes window.

In the list is 'SpiceModel', double-click on the word in the middle column. This magically turns into a combo (drop-down type) list box in which you can select any other available model (subckt).

'Enter' key twice, it am changed.

HTH (?)
 
"Entrenched convictions cannot be changed by facts." – Dick Francis
izzy wizzy
Old Hand
Posts: 1367
Joined: Fri Nov 02, 2007 7:02 pm
Location: Auckland NZ
Contact:

#155

Post by izzy wizzy »

the .txt files with the models in them live in the \sub folder

cheers,

Stephen
User avatar
IslandPink
Social Sevices have been notified
Posts: 8830
Joined: Tue May 29, 2007 7:01 pm
Location: Denbigh, N.Wales

#156

Post by IslandPink »

OK, thanks so far , I did as Stephen said and put the txt files in lib/sub
Mike H wrote:Open or create new schematic.
Click 'Component' button to choose a valve symbol, they're in 'Misc' section (usually).
Plonk symbol down wherever (attached to mouse, key 'Esc' to stop placing copies).
This bit had me flummoxed for ages as well!
Right mouse button click on the symbol.
This gets up the component attributes window.
So far so good, no probs on this .
Mike H wrote: In the list is 'SpiceModel', double-click on the word in the middle column. This magically turns into a combo (drop-down type) list box in which you can select any other available model (subckt).
No drop-down list box :(
I wrote 'KT88' in there, but nothing useful had happened to the component when I came out .

Also i have no idea what the circuit is that Nick gave me - either it got corrupted in reading in with no valve models, or it's not the correct file.
Anyhow, I should be able to construct what I want with a few edits , if I can get the valves to work .
"Peridots and periwinkle, blue medallions Gilded galleons spilled across the ocean floor" ( Mitchell )
User avatar
Mike H
Amstrad Tower of Power
Posts: 19053
Joined: Sat Oct 04, 2008 5:38 pm
Location: The Fens
Contact:

#157

Post by Mike H »

IslandPink wrote:No drop-down list box :(
Ah right, possiblee, this is because you have to use my symbols, assuming you're using my library for example. pentode_new, triode_new, tetrode_new, anyway something + '_new', (theres a suffix number for appearance style)

The bog standard LTspice ones do not have a model file specified (i.e. new_triodes.txt, new_tetrodes.txt etc.).

You could go to edit the standard symbol, save it as something unique and write in the ModelFile (e.g. new_triodes.txt) and SpiceModel (e.g. ECC81).

Ctrl+A to open the symbol's attributes window. And 'Value' should be blank.

Otherwise another possible reason is it can't find the .txt file, but according to the experts model libraries should be findable anywhere in the LTspiceIV directory tree.

NB: creating a new symbol requires LTspice to be closed then re-opened before it will appear in the components list.
 
"Entrenched convictions cannot be changed by facts." – Dick Francis
User avatar
Mike H
Amstrad Tower of Power
Posts: 19053
Joined: Sat Oct 04, 2008 5:38 pm
Location: The Fens
Contact:

#158

Post by Mike H »

IslandPink wrote:Also i have no idea what the circuit is that Nick gave me - either it got corrupted in reading in with no valve models, or it's not the correct file.
This happens if the symbol(s) can't be found on your machine. For this reason a schematic may need to be accompanied by symbols and associated sub-circuits if they are not of LTspice standard library.

HTH
 
"Entrenched convictions cannot be changed by facts." – Dick Francis
User avatar
IslandPink
Social Sevices have been notified
Posts: 8830
Joined: Tue May 29, 2007 7:01 pm
Location: Denbigh, N.Wales

#159

Post by IslandPink »

Haven't done any more yet Mike, but I can say that a tetrode symbol comes up, it's just that I can't give it specific name or properties .
"Peridots and periwinkle, blue medallions Gilded galleons spilled across the ocean floor" ( Mitchell )
User avatar
Mike H
Amstrad Tower of Power
Posts: 19053
Joined: Sat Oct 04, 2008 5:38 pm
Location: The Fens
Contact:

#160

Post by Mike H »

This is the sort of thing you should get when you double-click SpiceModel - this is triode_new2 that links to new_triodes.txt in the ModelFile attribute:

There was some talk a while ago on the yahoo group about some computers having trouble making the double-click work but can't remember the details - might have been Mac running Wine or something like that
Attachments
ltc-attributes.jpg
 
"Entrenched convictions cannot be changed by facts." – Dick Francis
User avatar
IslandPink
Social Sevices have been notified
Posts: 8830
Joined: Tue May 29, 2007 7:01 pm
Location: Denbigh, N.Wales

#161

Post by IslandPink »

No, thats not something I've seen yet .
And ( D'Oh! ) I need to get file that includes KT88 as a triode, which these .txt files do not .
OK, no , maybe actually I can use it as a tetrode if I just use the circuit with the screen connected to B+ ( and anode ) with just a 100R resistor - any comment ? - will it operate correctly ?

I'm off to the Lakes for a week, from tomorrow, so I think I'd better leave it till I come back to get it sorted. Any advice in the meantime gratefully received .
"Peridots and periwinkle, blue medallions Gilded galleons spilled across the ocean floor" ( Mitchell )
izzy wizzy
Old Hand
Posts: 1367
Joined: Fri Nov 02, 2007 7:02 pm
Location: Auckland NZ
Contact:

#162

Post by izzy wizzy »

Maybe helpful, maybe not. I've only used the setup from Intact audio an Stephie's drop down triode and tetrode models.

The downside to this is using .asc sims from other people. Sometimes I have to go and change the valves in the sim to the drop down models but that is really vary simple to do.

I do it this way coz it works for me. I'm sure if you really know what you're doing, there's another way :-)

cheers,

Stephen
User avatar
Mike H
Amstrad Tower of Power
Posts: 19053
Joined: Sat Oct 04, 2008 5:38 pm
Location: The Fens
Contact:

#163

Post by Mike H »

IslandPink wrote:And ( D'Oh! ) I need to get file that includes KT88 as a triode, which these .txt files do not .
OK, no , maybe actually I can use it as a tetrode if I just use the circuit with the screen connected to B+ ( and anode ) with just a 100R resistor - any comment ? - will it operate correctly ?
It will work, but still have more gain than reality, so a kosher triode model is still needed. I'll see if I can make one.
 
"Entrenched convictions cannot be changed by facts." – Dick Francis
User avatar
Mike H
Amstrad Tower of Power
Posts: 19053
Joined: Sat Oct 04, 2008 5:38 pm
Location: The Fens
Contact:

#164

Post by Mike H »

OK here it is, seems a pretty close match to MOV datasheet -

Copy and paste into new_triodes.txt (somewhere around EL34 / GM70)

Code: Select all

.subckt KT88 A G K ; as triode
XV1 A G K Triode
+params: mu=9.8 ex=1.35 kg1=410 kp=29 kvb=24.6
+cpg=7.9p ccg=9.3p ccp=17p rgi=1000
.ends
Attachments
kt88-plot.gif
 
"Entrenched convictions cannot be changed by facts." – Dick Francis
User avatar
Mike H
Amstrad Tower of Power
Posts: 19053
Joined: Sat Oct 04, 2008 5:38 pm
Location: The Fens
Contact:

#165

Post by Mike H »

Sorry grid lines in steps of 5V starting at green for zero

HTH
 
"Entrenched convictions cannot be changed by facts." – Dick Francis
Post Reply