Joerg expounded in news:9avc4lF6ipU5@mid.individual.net:> Fred_Bartoli wrote: >> >> "Joerg" <invalid@invalid.invalid> a �crit dans le message >> de news:9atnjvF3mpU1@mid.individual.net... >>> Jim Thompson wrote: >>>> On Mon, 15 Aug 2011 22:39:28 +0200, "Fred_Bartoli" >>>> <fred.removethis.bartoli.canxxxelthis@free.andthisbittoo. >>>> fr> wrote: >>>>> "Joerg" <invalid@invalid.invalid> a �crit dans le >>>>> message de news:9asobhFipoU1@mid.individual.net.....>>>>> Maybe I stumbled upon a bug here and if this is >>>>> corroborated..>> It's not spice fault, it's you that don't see the >> implication of what you're doing, as I already said. >> > > If it has problems with the matrix, then way doesn't it > issue a warning?Take the blue pill. Then the cracks in the matrix will disappear. Warren
Unconnected part LTSpice seems to need (weird ...)
Started by ●August 14, 2011
Reply by ●August 16, 20112011-08-16
Reply by ●August 16, 20112011-08-16
Warren wrote:> Joerg expounded in news:9avc4lF6ipU5@mid.individual.net: > >> Fred_Bartoli wrote: >>> "Joerg" <invalid@invalid.invalid> a �crit dans le message >>> de news:9atnjvF3mpU1@mid.individual.net... >>>> Jim Thompson wrote: >>>>> On Mon, 15 Aug 2011 22:39:28 +0200, "Fred_Bartoli" >>>>> <fred.removethis.bartoli.canxxxelthis@free.andthisbittoo. >>>>> fr> wrote: >>>>>> "Joerg" <invalid@invalid.invalid> a �crit dans le >>>>>> message de news:9asobhFipoU1@mid.individual.net... > .. >>>>>> Maybe I stumbled upon a bug here and if this is >>>>>> corroborated > .. >>> It's not spice fault, it's you that don't see the >>> implication of what you're doing, as I already said. >>> >> If it has problems with the matrix, then way doesn't it >> issue a warning? > > Take the blue pill. Then the cracks in the matrix will > disappear. >But all I have and take is white pills, calcium & magnesium supplement. Would those work? :-) -- Regards, Joerg http://www.analogconsultants.com/
Reply by ●August 16, 20112011-08-16
On Tue, 16 Aug 2011 16:31:05 +0000 (UTC), Warren <ve3wwg@gmail.com> wrote:>Joerg expounded in news:9avc4lF6ipU5@mid.individual.net: > >> Fred_Bartoli wrote: >>> >>> "Joerg" <invalid@invalid.invalid> a �crit dans le message >>> de news:9atnjvF3mpU1@mid.individual.net... >>>> Jim Thompson wrote: >>>>> On Mon, 15 Aug 2011 22:39:28 +0200, "Fred_Bartoli" >>>>> <fred.removethis.bartoli.canxxxelthis@free.andthisbittoo. >>>>> fr> wrote: >>>>>> "Joerg" <invalid@invalid.invalid> a �crit dans le >>>>>> message de news:9asobhFipoU1@mid.individual.net... >.. >>>>>> Maybe I stumbled upon a bug here and if this is >>>>>> corroborated >.. >>> It's not spice fault, it's you that don't see the >>> implication of what you're doing, as I already said. >>> >> >> If it has problems with the matrix, then way doesn't it >> issue a warning? > >Take the blue pill. Then the cracks in the matrix will >disappear. > >WarrenWhat if the cracks last more than four hours?
Reply by ●August 16, 20112011-08-16
On 08/16/2011 05:56 AM, Fred_Bartoli wrote:> > "Joerg" <invalid@invalid.invalid> a �crit dans le message de > news:9atnjvF3mpU1@mid.individual.net... >> Jim Thompson wrote: >>> On Mon, 15 Aug 2011 22:39:28 +0200, "Fred_Bartoli" >>> <fred.removethis.bartoli.canxxxelthis@free.andthisbittoo.fr> wrote: >>> >>>> "Joerg" <invalid@invalid.invalid> a �crit dans le message de >>>> news:9asobhFipoU1@mid.individual.net... >> >> [...] >> >>>> >>>> >>>> >>>> Maybe I stumbled upon a bug here and if this is corroborated >>>> >>>> Not at all. That's classic spice stuff :-) >>>> >>>>> by others I should send it in for Mike's crew. >>>>> >>>>> -- >>>>> Regards, Joerg >>>>> >>>>> http://www.analogconsultants.com/ >>> >>> It's probably as simple as a timestep set too large... or your Adobe is >>> getting gout again ;-) >>> >> >> It usually sez it in an error box when that happens. My point was that >> it seems to treat a diode with one electrode disconnected differently >> than the diode not being there at all. This defies logic. >> > > It doesn't defie logic at all when you don't refuse to understand that > once you put a diode somewhere, with at least a connection to the > network, it *is* included in the solving matrix. And doing so with one > unconnected side you *are* asking spice to solve an ill conditionned > system. Period.Whoa, there--it isn't so cut and dried. LTSpice has built-in heuristics to prune stuff like that before it runs, but they aren't perfect.> And ill conditionned systems can give you pretty chaotic results (change > some starting conditions just a little bit and you have 'unpredictable' > widely different result). No surprise there. > > It's not spice fault, it's you that don't see the implication of what > you're doing, as I already said.It's a reasonable question why it should work at all, though, and why it silently generates wrong answers without complaining. ISTM it's a minor bug in the heuristics. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net
Reply by ●August 16, 20112011-08-16
On Tue, 16 Aug 2011 13:10:21 -0400, Spehro Pefhany <speffSNIP@interlogDOTyou.knowwhat> wrote:>On Tue, 16 Aug 2011 16:31:05 +0000 (UTC), Warren <ve3wwg@gmail.com> >wrote: > >>Joerg expounded in news:9avc4lF6ipU5@mid.individual.net: >> >>> Fred_Bartoli wrote: >>>> >>>> "Joerg" <invalid@invalid.invalid> a �crit dans le message >>>> de news:9atnjvF3mpU1@mid.individual.net... >>>>> Jim Thompson wrote: >>>>>> On Mon, 15 Aug 2011 22:39:28 +0200, "Fred_Bartoli" >>>>>> <fred.removethis.bartoli.canxxxelthis@free.andthisbittoo. >>>>>> fr> wrote: >>>>>>> "Joerg" <invalid@invalid.invalid> a �crit dans le >>>>>>> message de news:9asobhFipoU1@mid.individual.net... >>.. >>>>>>> Maybe I stumbled upon a bug here and if this is >>>>>>> corroborated >>.. >>>> It's not spice fault, it's you that don't see the >>>> implication of what you're doing, as I already said. >>>> >>> >>> If it has problems with the matrix, then way doesn't it >>> issue a warning? >> >>Take the blue pill. Then the cracks in the matrix will >>disappear. >> >>Warren > >What if the cracks last more than four hours?Then she's going to have to finish by herself.
Reply by ●August 17, 20112011-08-17
Joerg expounded in news:9avm5mFpsuU1@mid.individual.net:> Warren wrote: >> Joerg expounded in news:9avc4lF6ipU5@mid.individual.net: >> >>> Fred_Bartoli wrote: >>>> "Joerg" <invalid@invalid.invalid> a �crit dans le >>>> message de news:9atnjvF3mpU1@mid.individual.net... >>>>> Jim Thompson wrote: >>>>>> On Mon, 15 Aug 2011 22:39:28 +0200, "Fred_Bartoli" >>>>>> <fred.removethis.bartoli.canxxxelthis@free.andthisbitto >>>>>> o. fr> wrote: >>>>>>> "Joerg" <invalid@invalid.invalid> a �crit dans le >>>>>>> message de news:9asobhFipoU1@mid.individual.net... >> .. >>>>>>> Maybe I stumbled upon a bug here and if this is >>>>>>> corroborated >> .. >>>> It's not spice fault, it's you that don't see the >>>> implication of what you're doing, as I already said. >>>> >>> If it has problems with the matrix, then way doesn't it >>> issue a warning? >> >> Take the blue pill. Then the cracks in the matrix will >> disappear. > > But all I have and take is white pills, calcium & magnesium > supplement. Would those work? > >:-)That only works for Morpheus. Warren
Reply by ●August 17, 20112011-08-17
Phil Hobbs wrote:> On 08/16/2011 05:56 AM, Fred_Bartoli wrote: >> >> "Joerg" <invalid@invalid.invalid> a �crit dans le message de >> news:9atnjvF3mpU1@mid.individual.net... >>> Jim Thompson wrote: >>>> On Mon, 15 Aug 2011 22:39:28 +0200, "Fred_Bartoli" >>>> <fred.removethis.bartoli.canxxxelthis@free.andthisbittoo.fr> wrote: >>>> >>>>> "Joerg" <invalid@invalid.invalid> a �crit dans le message de >>>>> news:9asobhFipoU1@mid.individual.net... >>> >>> [...] >>> >>>>> >>>>> >>>>> >>>>> Maybe I stumbled upon a bug here and if this is corroborated >>>>> >>>>> Not at all. That's classic spice stuff :-) >>>>> >>>>>> by others I should send it in for Mike's crew. >>>>>> >>>>>> -- >>>>>> Regards, Joerg >>>>>> >>>>>> http://www.analogconsultants.com/ >>>> >>>> It's probably as simple as a timestep set too large... or your Adobe is >>>> getting gout again ;-) >>>> >>> >>> It usually sez it in an error box when that happens. My point was that >>> it seems to treat a diode with one electrode disconnected differently >>> than the diode not being there at all. This defies logic. >>> >> >> It doesn't defie logic at all when you don't refuse to understand that >> once you put a diode somewhere, with at least a connection to the >> network, it *is* included in the solving matrix. And doing so with one >> unconnected side you *are* asking spice to solve an ill conditionned >> system. Period. > > Whoa, there--it isn't so cut and dried. LTSpice has built-in heuristics > to prune stuff like that before it runs, but they aren't perfect. >I prefer when software tells me before or after it prunes something.>> And ill conditionned systems can give you pretty chaotic results (change >> some starting conditions just a little bit and you have 'unpredictable' >> widely different result). No surprise there. >> >> It's not spice fault, it's you that don't see the implication of what >> you're doing, as I already said. > > It's a reasonable question why it should work at all, though, and why it > silently generates wrong answers without complaining. > > ISTM it's a minor bug in the heuristics. >Forrest Gump would have said "It's like a box of chocolates, you never know what you gonna get" :-) -- Regards, Joerg http://www.analogconsultants.com/
Reply by ●August 17, 20112011-08-17
On Wed, 17 Aug 2011 09:32:26 -0700, Joerg <invalid@invalid.invalid> wrote:>Phil Hobbs wrote: >> On 08/16/2011 05:56 AM, Fred_Bartoli wrote: >>> >>> "Joerg" <invalid@invalid.invalid> a �crit dans le message de >>> news:9atnjvF3mpU1@mid.individual.net... >>>> Jim Thompson wrote: >>>>> On Mon, 15 Aug 2011 22:39:28 +0200, "Fred_Bartoli" >>>>> <fred.removethis.bartoli.canxxxelthis@free.andthisbittoo.fr> wrote: >>>>> >>>>>> "Joerg" <invalid@invalid.invalid> a �crit dans le message de >>>>>> news:9asobhFipoU1@mid.individual.net... >>>> >>>> [...] >>>> >>>>>> >>>>>> >>>>>> >>>>>> Maybe I stumbled upon a bug here and if this is corroborated >>>>>> >>>>>> Not at all. That's classic spice stuff :-) >>>>>> >>>>>>> by others I should send it in for Mike's crew. >>>>>>> >>>>>>> -- >>>>>>> Regards, Joerg >>>>>>> >>>>>>> http://www.analogconsultants.com/ >>>>> >>>>> It's probably as simple as a timestep set too large... or your Adobe is >>>>> getting gout again ;-) >>>>> >>>> >>>> It usually sez it in an error box when that happens. My point was that >>>> it seems to treat a diode with one electrode disconnected differently >>>> than the diode not being there at all. This defies logic. >>>> >>> >>> It doesn't defie logic at all when you don't refuse to understand that >>> once you put a diode somewhere, with at least a connection to the >>> network, it *is* included in the solving matrix. And doing so with one >>> unconnected side you *are* asking spice to solve an ill conditionned >>> system. Period. >> >> Whoa, there--it isn't so cut and dried. LTSpice has built-in heuristics >> to prune stuff like that before it runs, but they aren't perfect. >> > >I prefer when software tells me before or after it prunes something. > > >>> And ill conditionned systems can give you pretty chaotic results (change >>> some starting conditions just a little bit and you have 'unpredictable' >>> widely different result). No surprise there. >>> >>> It's not spice fault, it's you that don't see the implication of what >>> you're doing, as I already said. >> >> It's a reasonable question why it should work at all, though, and why it >> silently generates wrong answers without complaining. >> >> ISTM it's a minor bug in the heuristics. >> > >Forrest Gump would have said "It's like a box of chocolates, you never >know what you gonna get" :-)Some sims will go from running in seconds to running in hours, with minor changes. I used to run a DOS sim, called ECA, that didn't use the Spice core. It was cool, ran very fast on a 486. It would announce, but cruise right through, warnings of singularities, divide by zero, all that stuff. It just kept going. John
Reply by ●August 17, 20112011-08-17
John Larkin wrote:> On Wed, 17 Aug 2011 09:32:26 -0700, Joerg <invalid@invalid.invalid> > wrote: > >> Phil Hobbs wrote: >>> On 08/16/2011 05:56 AM, Fred_Bartoli wrote:[...]>> >>>> And ill conditionned systems can give you pretty chaotic results (change >>>> some starting conditions just a little bit and you have 'unpredictable' >>>> widely different result). No surprise there. >>>> >>>> It's not spice fault, it's you that don't see the implication of what >>>> you're doing, as I already said. >>> It's a reasonable question why it should work at all, though, and why it >>> silently generates wrong answers without complaining. >>> >>> ISTM it's a minor bug in the heuristics. >>> >> Forrest Gump would have said "It's like a box of chocolates, you never >> know what you gonna get" :-) > > Some sims will go from running in seconds to running in hours, with > minor changes. > > I used to run a DOS sim, called ECA, that didn't use the Spice core. > It was cool, ran very fast on a 486. It would announce, but cruise > right through, warnings of singularities, divide by zero, all that > stuff. It just kept going. >Interesting, I also grew up with good old ECA224 but that was when the 286 was the latest and greatest. It was quite a useful simulator. Someone told me it merged into EWB but when I tried that at a client I did not like it anymore. For my consulting office I bought MicroSim PSpice. It came with those nice cloth covered IBM-style binders. I find this sim behavior odd. It seems only naturaly that, in a "what-if" scenario, an engineer disconnects just one leg of a part. After all, that's how we also do it in real life. SPICE is not supposed to "partially smoosh that" and then not tell anyone. -- Regards, Joerg http://www.analogconsultants.com/
Reply by ●August 17, 20112011-08-17
On 08/17/2011 12:32 PM, Joerg wrote:> Phil Hobbs wrote: >> On 08/16/2011 05:56 AM, Fred_Bartoli wrote: >>> >>> "Joerg"<invalid@invalid.invalid> a �crit dans le message de >>> news:9atnjvF3mpU1@mid.individual.net... >>>> Jim Thompson wrote: >>>>> On Mon, 15 Aug 2011 22:39:28 +0200, "Fred_Bartoli" >>>>> <fred.removethis.bartoli.canxxxelthis@free.andthisbittoo.fr> wrote: >>>>> >>>>>> "Joerg"<invalid@invalid.invalid> a �crit dans le message de >>>>>> news:9asobhFipoU1@mid.individual.net... >>>> >>>> [...] >>>> >>>>>> >>>>>> >>>>>> >>>>>> Maybe I stumbled upon a bug here and if this is corroborated >>>>>> >>>>>> Not at all. That's classic spice stuff :-) >>>>>> >>>>>>> by others I should send it in for Mike's crew. >>>>>>> >>>>>>> -- >>>>>>> Regards, Joerg >>>>>>> >>>>>>> http://www.analogconsultants.com/ >>>>> >>>>> It's probably as simple as a timestep set too large... or your Adobe is >>>>> getting gout again ;-) >>>>> >>>> >>>> It usually sez it in an error box when that happens. My point was that >>>> it seems to treat a diode with one electrode disconnected differently >>>> than the diode not being there at all. This defies logic. >>>> >>> >>> It doesn't defie logic at all when you don't refuse to understand that >>> once you put a diode somewhere, with at least a connection to the >>> network, it *is* included in the solving matrix. And doing so with one >>> unconnected side you *are* asking spice to solve an ill conditionned >>> system. Period. >> >> Whoa, there--it isn't so cut and dried. LTSpice has built-in heuristics >> to prune stuff like that before it runs, but they aren't perfect. >> > > I prefer when software tells me before or after it prunes something. >A lint-equivalent for SPICE netlists would be useful. But since most people seem to use SPICE by poking things until the sim looks nice, it's an experimental science anyway. ;) Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC 55 Orchard Rd Briarcliff Manor NY 10510 845-480-2058 email: hobbs@electrooptical.net http://electrooptical.net
