ID: | 4214 |
From: | gene glick <ge...@optonline.net> |
Date: | Wed, 24 Jun 2020 13:01:19 -0400 |
Subject: | Re: [pcb-rnd] Off topic (maybe) - Spice simulator |
in-reply-to: | 4213 from Robin Laing <Me...@TelusPlanet.net> |
replies: | 4215 from stefan <st...@gmail.com> , 4216 from Evan Foss <ev...@gmail.com> , 4219 from Gabriel Paubert <pa...@iram.es> |
--000000000000751f9b05a8d76de9 Content-Type: text/plain; charset="UTF-8" Can't you take a zener diode model and crank up the breakdown voltage? Alternatively, make a voltage controlled switch that turns on at the needed voltage. I think a voltage dependent current source might also do the job. I'll bet there are many other ways to do this as well. On Wed, Jun 24, 2020, 12:22 PM Robin Laing <MeSat@telusplanet.net> wrote: > On 23/06/2020 08:20, Anthony Tuttle wrote: > > LTspice has a neon lamp model that can work without being too prone to > > convergence issues. I have also used R={expression} as the resistance > > value in resistors to simulate switches and this may be workable for an > > improvised discharge model. > > > > There are spice models for GDTs, you may have to contact the > > manufacturer directly to gain access. They are never perfect but there > > has been some work on advanced GDT models. > > > > On Tue, Jun 23, 2020 at 1:41 AM stefan <stefan.schippers@gmail.com > > <mailto:stefan.schippers@gmail.com>> wrote: > > > > > >> Hello, > >> > >> I am involved with a project that will involve high voltage pulse > >> circuit design and I am looking for a circuit simulator that will > >> give > >> us an accurate representation of a circuit. > >> > >> Needs to work with spark gap technology as that is the present > >> design. > >> Maybe gas discharge tube as well. > >> > >> Presently one member of the team is trying to use Multisim from NI > >> but I > >> am wondering if there may be a better package. > >> > > NGSPICE developers are doing a good job, > > ngspice netlists may contain capacitors, resistors, inductors with > > arbitrary expressions about their value. > > Moreover the 'B source' allows any type of voltage/current source > > with arbitrary expressions. > > > > Combining these elements a model for a gas discharge/breakdown can > > be created. > > The big issue is not the simulator itself, but the quality of the > model: > > > > 1) ability to accurately describe the device. > > 2) simulator must converge to a solution. > > > > Breakdown devices (devices with infinite resistance that start > > conducting with very low resistance when a voltage threshold is > > reached) are famous for giving convergence issues. This usually > > happen due to poor model description. A current limit must be > > included in the equations (no physical device can sustain 1e15 Amp > > of current :-) ). > > > > Stefan > > > > Thank you to all. > > The breakdown is where I ran into problems with a model years ago. It > was quicker to just setup an test bed and try it. Don't do enough > design work to take the time to learn the simulator. Same reason that > Multisim is being used. > > Robin > > > > --000000000000751f9b05a8d76de9 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable <div dir=3D"auto">Can't you take a zener diode model and crank up the b= reakdown voltage? Alternatively, make a voltage controlled switch that turn= s on at the needed voltage. I think a voltage dependent current source migh= t also do the job.<div dir=3D"auto"><br></div><div dir=3D"auto">I'll be= t there are many other ways to do this as well.</div></div><br><div class= =3D"gmail_quote"><div dir=3D"ltr" class=3D"gmail_attr">On Wed, Jun 24, 2020= , 12:22 PM Robin Laing <<a href=3D"mailto:MeSat@telusplanet.net">MeSat@t= elusplanet.net</a>> wrote:<br></div><blockquote class=3D"gmail_quote" st= yle=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">On 23= /06/2020 08:20, Anthony Tuttle wrote:<br> > LTspice has a neon lamp model that can work without being too prone to= <br> > convergence issues. I have also used R=3D{expression} as the resistanc= e <br> > value in resistors to simulate switches and this may be workable for a= n <br> > improvised discharge model.<br> > <br> > There are spice models for GDTs, you may have to contact the <br> > manufacturer directly to gain access. They are never perfect=C2=A0but = there <br> > has been some work on advanced GDT models.<br> > <br> > On Tue, Jun 23, 2020 at 1:41 AM stefan <<a href=3D"mailto:stefan.sc= hippers@gmail.com" target=3D"_blank" rel=3D"noreferrer">stefan.schippers@gm= ail.com</a> <br> > <mailto:<a href=3D"mailto:stefan.schippers@gmail.com" target=3D"_bl= ank" rel=3D"noreferrer">stefan.schippers@gmail.com</a>>> wrote:<br> > <br> > <br> >>=C2=A0 =C2=A0 =C2=A0Hello,<br> >><br> >>=C2=A0 =C2=A0 =C2=A0I am involved with a project that will involve = high voltage pulse<br> >>=C2=A0 =C2=A0 =C2=A0circuit design and I am looking for a circuit s= imulator that will<br> >>=C2=A0 =C2=A0 =C2=A0give<br> >>=C2=A0 =C2=A0 =C2=A0us an accurate representation of a circuit.<br> >><br> >>=C2=A0 =C2=A0 =C2=A0Needs to work with spark gap technology as that= is the present<br> >>=C2=A0 =C2=A0 =C2=A0design.<br> >>=C2=A0 =C2=A0 =C2=A0Maybe gas discharge tube as well.<br> >><br> >>=C2=A0 =C2=A0 =C2=A0Presently one member of the team is trying to u= se Multisim from NI<br> >>=C2=A0 =C2=A0 =C2=A0but I<br> >>=C2=A0 =C2=A0 =C2=A0am wondering if there may be a better package.<= br> >><br> >=C2=A0 =C2=A0 =C2=A0NGSPICE developers are doing a good job,<br> >=C2=A0 =C2=A0 =C2=A0ngspice netlists may contain capacitors, resistors,= inductors with<br> >=C2=A0 =C2=A0 =C2=A0arbitrary expressions about their value.<br> >=C2=A0 =C2=A0 =C2=A0Moreover the 'B source' allows any type of = voltage/current source<br> >=C2=A0 =C2=A0 =C2=A0with arbitrary expressions.<br> > <br> >=C2=A0 =C2=A0 =C2=A0Combining these elements a model for a gas discharg= e/breakdown can<br> >=C2=A0 =C2=A0 =C2=A0be created.<br> >=C2=A0 =C2=A0 =C2=A0The big issue is not the simulator itself, but the = quality of the model:<br> > <br> >=C2=A0 =C2=A0 =C2=A01) ability to accurately describe the device.<br> >=C2=A0 =C2=A0 =C2=A02) simulator must converge to a solution.<br> > <br> >=C2=A0 =C2=A0 =C2=A0Breakdown devices (devices with infinite resistance= that start<br> >=C2=A0 =C2=A0 =C2=A0conducting with very low resistance when a voltage = threshold is<br> >=C2=A0 =C2=A0 =C2=A0reached) are famous for giving convergence issues. = This usually<br> >=C2=A0 =C2=A0 =C2=A0happen due to poor model description. A current lim= it must be<br> >=C2=A0 =C2=A0 =C2=A0included in the equations (no physical device can s= ustain 1e15 Amp<br> >=C2=A0 =C2=A0 =C2=A0of current :-) ).<br> > <br> >=C2=A0 =C2=A0 =C2=A0Stefan<br> > <br> <br> Thank you to all.<br> <br> The breakdown is where I ran into problems with a model years ago.=C2=A0 It= <br> was quicker to just setup an test bed and try it.=C2=A0 Don't do enough= <br> design work to take the time to learn the simulator.=C2=A0 Same reason that= <br> Multisim is being used.<br> <br> Robin<br> <br> <br> <br> </blockquote></div> --000000000000751f9b05a8d76de9--
Reply subtree:
4214 Re: [pcb-rnd] Off topic (maybe) - Spice simulator from gene glick <ge...@optonline.net>
4215 Re: [pcb-rnd] Off topic (maybe) - Spice simulator from stefan <st...@gmail.com>
4222 Re: [pcb-rnd] Off topic (maybe) - Spice simulator -- from N <ni...@gmail.com>
4216 Re: [pcb-rnd] Off topic (maybe) - Spice simulator from Evan Foss <ev...@gmail.com>
4217 Re: [pcb-rnd] Off topic (maybe) - Spice simulator from gene glick <ge...@optonline.net>
4218 Re: [pcb-rnd] Off topic (maybe) - Spice simulator from Evan Foss <ev...@gmail.com>
4224 Re: [pcb-rnd] Off topic (maybe) - Spice simulator - openems from N <ni...@gmail.com>
4228 Re: [pcb-rnd] Off topic (maybe) - Spice simulator from Robin Laing <Me...@TelusPlanet.net>
4229 Re: [pcb-rnd] Off topic (maybe) - Spice simulator from Evan Foss <ev...@gmail.com>
4231 Re: [pcb-rnd] Off topic (maybe) - Spice simulator from Robin Laing <Me...@TelusPlanet.net>
4232 Re: [pcb-rnd] Off topic (maybe) - Spice simulator from Evan Foss <ev...@gmail.com>
4248 Re: [pcb-rnd] Off topic (maybe) - Spice simulator from Robin Laing <Me...@TelusPlanet.net>
4233 Re: [pcb-rnd] Off topic (maybe) - Spice simulator from gene glick <ge...@optonline.net>
4247 Re: [pcb-rnd] Off topic (maybe) - Spice simulator from Robin Laing <Me...@TelusPlanet.net>
4219 Re: [pcb-rnd] Off topic (maybe) - Spice simulator from Gabriel Paubert <pa...@iram.es>
4220 Re: [pcb-rnd] Off topic (maybe) - Spice simulator from Evan Foss <ev...@gmail.com>
4223 Re: [pcb-rnd] Off topic (maybe) - Spice simulator - sparc model from N <ni...@gmail.com>