Got it installed with wine here on my PC. Fonts are a bit wonky, but that happens from time to time, so not going to really bother with it. Took things for a spin by trying to build your basic low-pass filter as one might see on a momentary-contact button (etc.). Thing is, I wasn't seeing any "switch" or "button" type symbols -- am I just blind, and missed them somewhere in the myriad of semi-cryptic parts, or is it just that they happen to not be modeled in the base product? -- |_|O|_| |_|_|O| Github: https://github.com/dpurgert |O|O|O| PGP: DDAB 23FB 19FA 7D85 1CC1 E067 6D65 70E5 4CE7 2860
LTSpice - Am I blind?
Started by ●January 2, 2024
Reply by ●January 2, 20242024-01-02
tirsdag den 2. januar 2024 kl. 22.17.33 UTC+1 skrev Dan Purgert:> Got it installed with wine here on my PC. Fonts are a bit wonky, but > that happens from time to time, so not going to really bother with it. > > Took things for a spin by trying to build your basic low-pass filter as > one might see on a momentary-contact button (etc.). > > Thing is, I wasn't seeing any "switch" or "button" type symbols -- am I > just blind, and missed them somewhere in the myriad of semi-cryptic > parts, or is it just that they happen to not be modeled in the base > product?you use a voltage controlled switch, https://www.analog.com/en/technical-articles/ltspiceiv-voltage-controlled-switches.html a button is not a thing in spice , how would you push the button for simulation?
Reply by ●January 2, 20242024-01-02
On Tue, 2 Jan 2024 21:17:27 -0000 (UTC), Dan Purgert <dan@djph.net> wrote:>Got it installed with wine here on my PC. Fonts are a bit wonky, but >that happens from time to time, so not going to really bother with it. > >Took things for a spin by trying to build your basic low-pass filter as >one might see on a momentary-contact button (etc.). > >Thing is, I wasn't seeing any "switch" or "button" type symbols -- am I >just blind, and missed them somewhere in the myriad of semi-cryptic >parts, or is it just that they happen to not be modeled in the base >product?There's a voltage-controlled switch SW. Ask HELP to search for 'switch'. S is in the index too. In the component selector, search for SW. It needs a .model statement. Use a voltage source to switch it. Or just poke a voltage source into your filter. Or use a voltage source and a mosfet.
Reply by ●January 2, 20242024-01-02
On 2024-01-02, john larkin wrote:> On Tue, 2 Jan 2024 21:17:27 -0000 (UTC), Dan Purgert <dan@djph.net> > wrote: > >>Got it installed with wine here on my PC. Fonts are a bit wonky, but >>that happens from time to time, so not going to really bother with it. >> >>Took things for a spin by trying to build your basic low-pass filter as >>one might see on a momentary-contact button (etc.). >> >>Thing is, I wasn't seeing any "switch" or "button" type symbols -- am I >>just blind, and missed them somewhere in the myriad of semi-cryptic >>parts, or is it just that they happen to not be modeled in the base >>product? > > There's a voltage-controlled switch SW. Ask HELP to search for > 'switch'.Yeah, I saw that. I was looking for "generic bogus button" type "switch" (not that sw or csw wouldn't work). I'll probably just work-around it by inserting one of the variable voltage sources I noticed (IIRC, one said it'd do square wave, I think). -- |_|O|_| |_|_|O| Github: https://github.com/dpurgert |O|O|O| PGP: DDAB 23FB 19FA 7D85 1CC1 E067 6D65 70E5 4CE7 2860
Reply by ●January 2, 20242024-01-02
On Tue, 2 Jan 2024 22:26:46 -0000 (UTC), Dan Purgert <dan@djph.net> wrote:>On 2024-01-02, john larkin wrote: >> On Tue, 2 Jan 2024 21:17:27 -0000 (UTC), Dan Purgert <dan@djph.net> >> wrote: >> >>>Got it installed with wine here on my PC. Fonts are a bit wonky, but >>>that happens from time to time, so not going to really bother with it. >>> >>>Took things for a spin by trying to build your basic low-pass filter as >>>one might see on a momentary-contact button (etc.). >>> >>>Thing is, I wasn't seeing any "switch" or "button" type symbols -- am I >>>just blind, and missed them somewhere in the myriad of semi-cryptic >>>parts, or is it just that they happen to not be modeled in the base >>>product? >> >> There's a voltage-controlled switch SW. Ask HELP to search for >> 'switch'. > >Yeah, I saw that. I was looking for "generic bogus button" type "switch" >(not that sw or csw wouldn't work). I'll probably just work-around it >by inserting one of the variable voltage sources I noticed (IIRC, one >said it'd do square wave, I think).Yeah, the V voltage source (in "advanced" mode) has a pulse generator mode. I usually specify a rise and fall time. LT is a little weird if you use defaults. Note that if Tr=Tf=Ton=1, it's above zero for 3 seconds. Ton is the flat part.
Reply by ●January 2, 20242024-01-02
On Tue, 02 Jan 2024 14:42:36 -0800, john larkin <jl@650pot.com> wrote:>On Tue, 2 Jan 2024 22:26:46 -0000 (UTC), Dan Purgert <dan@djph.net> >wrote: > >>On 2024-01-02, john larkin wrote: >>> On Tue, 2 Jan 2024 21:17:27 -0000 (UTC), Dan Purgert <dan@djph.net> >>> wrote: >>> >>>>Got it installed with wine here on my PC. Fonts are a bit wonky, but >>>>that happens from time to time, so not going to really bother with it. >>>> >>>>Took things for a spin by trying to build your basic low-pass filter as >>>>one might see on a momentary-contact button (etc.). >>>> >>>>Thing is, I wasn't seeing any "switch" or "button" type symbols -- am I >>>>just blind, and missed them somewhere in the myriad of semi-cryptic >>>>parts, or is it just that they happen to not be modeled in the base >>>>product? >>> >>> There's a voltage-controlled switch SW. Ask HELP to search for >>> 'switch'. >> >>Yeah, I saw that. I was looking for "generic bogus button" type "switch" >>(not that sw or csw wouldn't work). I'll probably just work-around it >>by inserting one of the variable voltage sources I noticed (IIRC, one >>said it'd do square wave, I think). > >Yeah, the V voltage source (in "advanced" mode) has a pulse generator >mode. > >I usually specify a rise and fall time. LT is a little weird if you >use defaults. > >Note that if Tr=Tf=Ton=1, it's above zero for 3 seconds. Ton is the >flat part.Sometimes it's handy to use a sine wave source and square it up with a comparator. That makes square waves easier. An e with a tanh function makes a nice comparator.
Reply by ●January 2, 20242024-01-02
On 2024-01-02, john larkin wrote:> On Tue, 2 Jan 2024 22:26:46 -0000 (UTC), Dan Purgert <dan@djph.net> > wrote: > >>On 2024-01-02, john larkin wrote: >>> On Tue, 2 Jan 2024 21:17:27 -0000 (UTC), Dan Purgert <dan@djph.net> >>> wrote: >>> >>>>Got it installed with wine here on my PC. Fonts are a bit wonky, but >>>>that happens from time to time, so not going to really bother with it. >>>> >>>>Took things for a spin by trying to build your basic low-pass filter as >>>>one might see on a momentary-contact button (etc.). >>>> >>>>Thing is, I wasn't seeing any "switch" or "button" type symbols -- am I >>>>just blind, and missed them somewhere in the myriad of semi-cryptic >>>>parts, or is it just that they happen to not be modeled in the base >>>>product? >>> >>> There's a voltage-controlled switch SW. Ask HELP to search for >>> 'switch'. >> >>Yeah, I saw that. I was looking for "generic bogus button" type "switch" >>(not that sw or csw wouldn't work). I'll probably just work-around it >>by inserting one of the variable voltage sources I noticed (IIRC, one >>said it'd do square wave, I think). > > Yeah, the V voltage source (in "advanced" mode) has a pulse generator > mode. > > I usually specify a rise and fall time. LT is a little weird if you > use defaults.Yes, I'm starting to notice that :)> > Note that if Tr=Tf=Ton=1, it's above zero for 3 seconds. Ton is the > flat part. >Thanks (and for the hint about comparators). Lots to learn here :) -- |_|O|_| |_|_|O| Github: https://github.com/dpurgert |O|O|O| PGP: DDAB 23FB 19FA 7D85 1CC1 E067 6D65 70E5 4CE7 2860
Reply by ●January 2, 20242024-01-02
On Tue, 02 Jan 2024 14:58:21 -0800, john larkin <jl@650pot.com> wrote:>On Tue, 02 Jan 2024 14:42:36 -0800, john larkin <jl@650pot.com> wrote: > >>On Tue, 2 Jan 2024 22:26:46 -0000 (UTC), Dan Purgert <dan@djph.net> >>wrote: >> >>>On 2024-01-02, john larkin wrote: >>>> On Tue, 2 Jan 2024 21:17:27 -0000 (UTC), Dan Purgert <dan@djph.net> >>>> wrote: >>>> >>>>>Got it installed with wine here on my PC. Fonts are a bit wonky, but >>>>>that happens from time to time, so not going to really bother with it. >>>>> >>>>>Took things for a spin by trying to build your basic low-pass filter as >>>>>one might see on a momentary-contact button (etc.). >>>>> >>>>>Thing is, I wasn't seeing any "switch" or "button" type symbols -- am I >>>>>just blind, and missed them somewhere in the myriad of semi-cryptic >>>>>parts, or is it just that they happen to not be modeled in the base >>>>>product? >>>> >>>> There's a voltage-controlled switch SW. Ask HELP to search for >>>> 'switch'. >>> >>>Yeah, I saw that. I was looking for "generic bogus button" type "switch" >>>(not that sw or csw wouldn't work). I'll probably just work-around it >>>by inserting one of the variable voltage sources I noticed (IIRC, one >>>said it'd do square wave, I think). >> >>Yeah, the V voltage source (in "advanced" mode) has a pulse generator >>mode. >> >>I usually specify a rise and fall time. LT is a little weird if you >>use defaults. >> >>Note that if Tr=Tf=Ton=1, it's above zero for 3 seconds. Ton is the >>flat part. > >Sometimes it's handy to use a sine wave source and square it up with a >comparator. That makes square waves easier. > >An e with a tanh function makes a nice comparator.Not e, but BV. If node J is a sine wave, a BV with equation V = tanh(9K*V(J)) makes a nice square wave. The lamented Jim Thompson turned me on to tanh.
Reply by ●January 2, 20242024-01-02
John Larkin <jl@997PotHill.com> wrote:> On Tue, 02 Jan 2024 14:58:21 -0800, john larkin <jl@650pot.com> wrote: > >> On Tue, 02 Jan 2024 14:42:36 -0800, john larkin <jl@650pot.com> wrote: >> >>> On Tue, 2 Jan 2024 22:26:46 -0000 (UTC), Dan Purgert <dan@djph.net> >>> wrote: >>> >>>> On 2024-01-02, john larkin wrote: >>>>> On Tue, 2 Jan 2024 21:17:27 -0000 (UTC), Dan Purgert <dan@djph.net> >>>>> wrote: >>>>> >>>>>> Got it installed with wine here on my PC. Fonts are a bit wonky, but >>>>>> that happens from time to time, so not going to really bother with it. >>>>>> >>>>>> Took things for a spin by trying to build your basic low-pass filter as >>>>>> one might see on a momentary-contact button (etc.). >>>>>> >>>>>> Thing is, I wasn't seeing any "switch" or "button" type symbols -- am I >>>>>> just blind, and missed them somewhere in the myriad of semi-cryptic >>>>>> parts, or is it just that they happen to not be modeled in the base >>>>>> product? >>>>> >>>>> There's a voltage-controlled switch SW. Ask HELP to search for >>>>> 'switch'. >>>> >>>> Yeah, I saw that. I was looking for "generic bogus button" type "switch" >>>> (not that sw or csw wouldn't work). I'll probably just work-around it >>>> by inserting one of the variable voltage sources I noticed (IIRC, one >>>> said it'd do square wave, I think). >>> >>> Yeah, the V voltage source (in "advanced" mode) has a pulse generator >>> mode. >>> >>> I usually specify a rise and fall time. LT is a little weird if you >>> use defaults. >>> >>> Note that if Tr=Tf=Ton=1, it's above zero for 3 seconds. Ton is the >>> flat part. >> >> Sometimes it's handy to use a sine wave source and square it up with a >> comparator. That makes square waves easier. >> >> An e with a tanh function makes a nice comparator. > > Not e, but BV. If node J is a sine wave, a BV with equation > > V = tanh(9K*V(J)) > > makes a nice square wave. > > The lamented Jim Thompson turned me on to tanh. > >The standard ltspice switch has a nice infinitely-differentiable characteristic if you specify a negative hysteresis value. It’s an arctan rather than tanh, but it works just as well. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics
Reply by ●January 3, 20242024-01-03
On Tuesday, January 2, 2024 at 4:26:54 PM UTC-6, Dan Purgert wrote:> On 2024-01-02, john larkin wrote: > > On Tue, 2 Jan 2024 21:17:27 -0000 (UTC), Dan Purgert <d...@djph.net> > > wrote: > > > >>Got it installed with wine here on my PC. Fonts are a bit wonky, but > >>that happens from time to time, so not going to really bother with it. > >> > >>Took things for a spin by trying to build your basic low-pass filter as > >>one might see on a momentary-contact button (etc.). > >> > >>Thing is, I wasn't seeing any "switch" or "button" type symbols -- am I > >>just blind, and missed them somewhere in the myriad of semi-cryptic > >>parts, or is it just that they happen to not be modeled in the base > >>product? > > > > There's a voltage-controlled switch SW. Ask HELP to search for > > 'switch'. > Yeah, I saw that. I was looking for "generic bogus button" type "switch" > (not that sw or csw wouldn't work). I'll probably just work-around it > by inserting one of the variable voltage sources I noticed (IIRC, one > said it'd do square wave, I think). > -- > |_|O|_| > |_|_|O| Github: https://github.com/dpurgert > |O|O|O| PGP: DDAB 23FB 19FA 7D85 1CC1 E067 6D65 70E5 4CE7 2860I was once bitten by the difference between a switch and a pulse voltage source. The switch can close to supply the voltage, but, importantly, when it opens, it does not short the input of your load like a source will. You could put a diode in series with a pulsing voltage source to sort-of do the same as a switch, but then there is the diode drop to consider. Just my $.02 dollars.
