NE-2 I-V Curve ??

John,

Opening the FULL schematic with LTspice, got an error message about not valid schematic, then LTspice would abort.

Little window, before closing: "Aborting ...unknown schematic syntax"

But, after removing the above section LTspice had no problem, expect had missing neon symbol, ...and characteristics. I then added from misc my own neonbulb and labeled per your description, [80V 60V] and found only these three lines describing the neonbulb, not four. Examining the list, they appeared identical, except:

SYMBOL Misc\\neonbulb -48 272 R0 SYMATTR InstName NE1 SYMATTR Value2 Vstrike=80 Vhold=60

Note: WINDOW line is missing, so I went back and removed that single line from your list, making it supposedly identical to mine, and STILL got the abort message ??!! Anybody else experience this?

YES, this thing is fast analysis.

This one worked:

Version 4 SHEET 1 880 680 WIRE -272 208 -320 208 WIRE -160 208 -192 208 WIRE -48 208 -160 208 WIRE 48 208 -48 208 WIRE -48 224 -48 208 WIRE -320 240 -320 208 WIRE -160 240 -160 208 WIRE -320 336 -320 320 WIRE -160 336 -160 304 WIRE -160 336 -320 336 WIRE -48 336 -48 320 WIRE -48 336 -160 336 WIRE -320 384 -320 336 FLAG -320 384 0 FLAG 48 208 OUT SYMBOL Misc\\neonbulb -48 272 R0 SYMATTR InstName NE1 SYMATTR Value2 Vstrike=80 Vhold=60 SYMBOL cap -176 240 R0 SYMATTR InstName C1

SYMBOL voltage -320 224 R0 WINDOW 123 0 0 Left 2 WINDOW 0 44 56 Left 2 WINDOW 3 31 87 Left 2 SYMATTR InstName V1 SYMATTR Value 150 SYMATTR SpiceLine Rser=0 SYMBOL res -176 192 R90 WINDOW 0 -33 58 VBottom 2 WINDOW 3 -32 58 VTop 2 SYMATTR InstName R1 SYMATTR Value 10meg TEXT -272 360 Left 2 !.tran 0 10s 0 0.01s uic TEXT -272 392 Left 2 ;NEON RELAXATION OSCILLATOR TEXT -272 424 Left 2 ;JOHN FIELDS, 19 MARCH 2014

(snip SPICE list)

Works beautifully, John. Exactly as expected.

John S

You didn't have any trouble in copying and opening and running that ??!! see my response.

No, Robert, I didn't. I simply cut John's list and pasted it into a text file (but changed the extension to .asc) and it worked right off.

I'm sorry that I can't help you.

John S

FOUND IT !!!

Not LTspice problem, but my server/browser interaction !!!

When I ctr-c'd the text and copied it to a blank notepad page, I then saved as *.asc, which opens with LTspice.

I did not modify the text copy in anyway, which caused the whole list to be saved WITHOUT the LF's in the file!

All I have to do is remove one space at the bottom, THEN save and somehow every line gets that CR-LF combination that LTspice wants to see.

So, John, your schematic worked instantly once it was modified that small bit.

I know, who cares? but someone out there may have been bitten by this quirk and could save them big headaches.

We keep crossing posts!

I found it and laboriously explained what happened in the other post.

Sorry, Robert.

No. The closest I came to that was when the local Motorola rep dropped by my university and handed out some bare 68000 dies to the EE students. I'm pretty sure I've never met anyone from this newsgroup in the flesh.

All true. However the point he makes is perfectly valid, namely that the current is no more than a few electrons per second until avalanche starts. That's hard to do even in double precision.

Cheers

Phil Hobbs

Mine's essentially the same except for parts values.

LT Spice can run fast or slow with tiny changes of values or parameters. I have one circuit that never converges if I do a 50 us transient analysis run, but runs instantly if I sim it for 51.

I really liked the old Dos simulator ECA. It was fast and always converged somehow. It would occasionally say "divide by zero" or something, but it kept going. Dumb rectangular integration or something.

Hey, plug in Jim's TANH version and see how well that oscillates.

Having trouble?

Sometimes LT Spice converges very slowly. It's not the parts so much as it's Spice itself. Usually you can fiddle with sim params or values to get it to run faster, but I haven't found a predictable way to do that.

I wish there was a min time step setting, or better yet a fixed time step setting.

Same circuit, 150 volts, 1 megohm, 10 nF.

There are in Spice variants you pay for. I think there's a way in LTspice, also, to set Tstepmax, but I'll leave it up to you to find it

...Jim Thompson

I really wish you guys would just put a potato in your shorts or whatever it takes to make you feel confident enough to lay off this crapola.

Hint: put the potato in the front, not the back.

Cheers

Phil Hobbs

I'd like to know how to get LT Spice to quit saying "Stepping source 12 gazillion N-R iterations 165 fill-ins" for minutes at a time, and just get on with it. Hitting esc a couple of times often works, but it's silly.

What a setup... Larkin's "potato" is clearly in the back... of his diaper >:-} ...Jim Thompson