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LTSpice resistive divider

Started by Piotr Wyderski June 16, 2022
Hi,

what has recently happened to my Spice? Below is a simple resistor 
divider and this is the R2 voltage:

https://i.postimg.cc/SxPYBV2c/spice.png

Switching between solvers doesn't make any difference.

	Best regards, Piotr

Version 4
SHEET 1 880 680
WIRE 208 32 96 32
WIRE 368 32 288 32
WIRE 368 48 368 32
WIRE 96 80 96 32
WIRE 96 176 96 160
WIRE 368 176 368 128
FLAG 96 176 0
FLAG 368 176 0
SYMBOL voltage 96 64 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value SINE(0 320 50)
SYMBOL res 352 32 R0
SYMATTR InstName R1
SYMATTR Value 64
SYMBOL res 304 16 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R2
SYMATTR Value 10m
TEXT 64 200 Left 2 !.tran 1

Piotr Wyderski wrote:

> https://i.postimg.cc/SxPYBV2c/spice.png
Reinstalling Spice doesn't help either. Would it be the new physics they've been looking for at CERN recently? Best regards, Piotr
On Thursday, June 16, 2022 at 12:49:32 PM UTC-4, Piotr Wyderski wrote:
> Piotr Wyderski wrote: > > > https://i.postimg.cc/SxPYBV2c/spice.png > > Reinstalling Spice doesn't help either. Would it be the new physics > they've been looking for at CERN recently?
I entered the schematic from scratch and get the same thing. I suspect the solder joints. Try touching them up with a hot iron and lots of flux. -- Rick C. - Get 1,000 miles of free Supercharging - Tesla referral code - https://ts.la/richard11209
Ricky wrote:
> On Thursday, June 16, 2022 at 12:49:32 PM UTC-4, Piotr Wyderski wrote: >> Piotr Wyderski wrote: >> >>> https://i.postimg.cc/SxPYBV2c/spice.png >> >> Reinstalling Spice doesn't help either. Would it be the new physics >> they've been looking for at CERN recently? > > I entered the schematic from scratch and get the same thing. I suspect the solder joints. Try touching them up with a hot iron and lots of flux. >
Thanks for the heads-up, Piotr. It does it for me too, at least in XVII. It only seems to do it with the "modified trap" integrator--switching to plain trapezoid or Gear fixes it, it looks like. None of the tolerances I fiddled with did anything. It works fine in LTspice IV. That's a super good test case for a bug report! (JT, were he here to see it, would be crowing about how much better Original Crispy PSPICE was. RIP.) Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Phil Hobbs wrote:

> Thanks for the heads-up, Piotr.
No problem, albeit I am shocked that you both can replicate it. I was sure it was due to my messing up with the Control Panel parameters. Now I am getting worried: how many planes above my head were simulated with this tool? ;-)
> It only seems to do it with the "modified trap" integrator--switching to > plain trapezoid or Gear fixes it, it looks like.
So does tran 40m instead of tran 1 with the default settings.
> That's a super good test case for a bug report!
Reported. Best regards, Piotr
On Thu, 16 Jun 2022 13:21:01 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>Ricky wrote: >> On Thursday, June 16, 2022 at 12:49:32 PM UTC-4, Piotr Wyderski wrote: >>> Piotr Wyderski wrote: >>> >>>> https://i.postimg.cc/SxPYBV2c/spice.png >>> >>> Reinstalling Spice doesn't help either. Would it be the new physics >>> they've been looking for at CERN recently? >> >> I entered the schematic from scratch and get the same thing. I suspect the solder joints. Try touching them up with a hot iron and lots of flux. >> > >Thanks for the heads-up, Piotr. It does it for me too, at least in XVII. > >It only seems to do it with the "modified trap" integrator--switching to >plain trapezoid or Gear fixes it, it looks like. > >None of the tolerances I fiddled with did anything. > >It works fine in LTspice IV. > >That's a super good test case for a bug report! > >(JT, were he here to see it, would be crowing about how much better >Original Crispy PSPICE was. RIP.) > >Cheers > >Phil Hobbs
It looks OK with a smaller time step. -- If a man will begin with certainties, he shall end with doubts, but if he will be content to begin with doubts he shall end in certainties. Francis Bacon
Piotr Wyderski wrote:

> Reported.
Or not. Apparently, my location is essential. How would our beloved P. Allison respond to that? Hi Piotr, For technical support, ADI requests additional contact information. Please reply to this email with your: Company or University Email address Phone number Name of your Company or University Office Address, City, State, Zip Code Regards, ADI Tech Support
On 16/06/2022 6:45 pm, Piotr Wyderski wrote:
> > So does tran 40m instead of tran 1 with the default settings. >
Not quite, with the default "modified trap" setting using 40ms tran does indeed give the proper waveshape but the voltages are still wrong! piglet
On Thursday, June 16, 2022 at 2:23:23 PM UTC-4, Piotr Wyderski wrote:
> Piotr Wyderski wrote: > > > Reported. > > Or not. Apparently, my location is essential. How would our beloved P. > Allison respond to that? > > Hi Piotr, > For technical support, ADI requests additional contact information. > Please reply to this email with your: > > Company or University Email address > Phone number > Name of your Company or University > Office Address, City, State, Zip Code > > Regards, > ADI Tech Support
Their way to filtering out the rif-raff, obviously. The "company" email address only means no Yahoo or Gmail accounts, even if that's what you actually use. There's an ADI part I want to redesign out because of price. The only alternative I've found so far is a Maxim part that can be even higher priced... and is now an ADI part. lol Low resistance, high voltage analog switch. Powered from &plusmn;12V and around 2-3 ohms, quad in a TSSOP-16. Being able to get the Maxim part was hugely important when the ADI part was not available. -- Rick C. + Get 1,000 miles of free Supercharging + Tesla referral code - https://ts.la/richard11209
Piotr Wyderski wrote:
> Piotr Wyderski wrote: > >> Reported. > > Or not. Apparently, my location is essential. How would our beloved P. > Allison respond to that? > > Hi Piotr, > For technical support, ADI requests additional contact information. > Please reply to this email with your: > > Company or University Email address > Phone number > Name of your Company or University > Office Address, City, State, Zip Code > > Regards, > ADI Tech Support > >
Well, it's nice for them to be able to phone you up for clarification. An address along the lines of "1600 Pennsylvania Ave NW, Washington DC 20500" is always good. ;) Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com