ID: | 4220 |
From: | Evan Foss <ev...@gmail.com> |
Date: | Wed, 24 Jun 2020 16:38:50 -0400 |
Subject: | Re: [pcb-rnd] Off topic (maybe) - Spice simulator |
in-reply-to: | 4219 from Gabriel Paubert <pa...@iram.es> |
replies: | 4223 from N <ni...@gmail.com> |
It's also worth noting that because of the nature of plasma it's going to change DC vs AC. I saw a few hundred volt DC arc flash once. I don't recommend it. On Wed, Jun 24, 2020 at 4:31 PM Gabriel Paubert <paubert@iram.es> wrote: > > On Wed, Jun 24, 2020 at 01:01:19PM -0400, gene glick wrote: > > Can't you take a zener diode model and crank up the breakdown voltage? > > I don't think so, it has hysteresis, even worse than negative dynamic > resistance found in tunnel diodes. At least the model has to switch > between two states depending on past conditions. > > If you find a working diac model, it might be a reasonable starting > point: > > https://www.electronicdesign.com/power-management/article/21798585/model-diacs-and-triacs-for-acline-control > > as you can see, the model includes a flip flop. > > Gabriel > > > > 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 > > > > > > > > > > > > > > > > -- https://github.com/evanfoss -----BEGIN PGP PUBLIC KEY BLOCK----- Version: GnuPG v2 mQENBFYy4RYBCAC183JomLtbdAlcKiaPDoVHq52LDmVmH75aiEc69m7YxDt54/ai VtYCAobbGVIyn3Hlz3uhF6LnPl/6Lm1VdnCfpwu3KQhCO6ds10ow2C30X4ohCqOd hCVg5C+ILmQkEffFrFODy3ji+PYTF4pADvHCWsTMv0hf0llwFOJsBCK6cl02IffE JPqy4PjM1nZ9HpzT84JBaG/4OGvTZ8SQ2yFUl265jagvygPTf88H1xpZHH1r8dB1 stjUHLmPH8AOyDgKxFchgGeDc3p/vJtgDDIXAFfDXG0NSRovLmtaQdGxe47Zf/go bXiEM7YL2WqQe5zfEA919JxkEwlDKYniOSVzABEBAAG0N0V2YW4gRm9zcyAoVGhp cyBpcyBteSBwdWJsaWMga2V5LikgPGV2YW5mb3NzQGdtYWlsLmNvbT6JATkEEwEC ACMFAlYy4RYCGwMHCwkIBwMCAQYVCAIJCgsEFgIDAQIeAQIXgAAKCRCIpQTcE8nN bbBaCACAm8pU5lG1ev2Fsw68Axtcl57SJrYieqX96c3YuYH9JpqMqJRnd9nDKw9X tQuvuH7tUk0VbOaDqReOYJVI/4c5wb9AaOFp6K2DUcupq6XhgXpvz3HzoPwjAdIj XuQzdRUx5+innTJrSkGuBYW/CZ2zqEx4xfLlq4rO0hoTUMR8QVp2cCrkw6BT0m86 APIw/ZnjoxM8IEzr7MxfRIg3qpzrZk28rmhx+k78Jyk61UhwcCPGIm/pjUopTwYJ 3YBdRB2cYD2aN7A1JVf5cRmSQYooHBGpH0kYvomGk97PKqypVuJ7OpG9xM58wUcC qUVt9hKlePLzP8csYjt8onqI7qIIuQENBFYy4RYBCADlH8spG3WkCx62vB5mr5Z0 SCDd/RcyA4A5y5EOj5KurQkrSWpgi9Ho1yKruMJ6blQR2qkc66KqH9pnXDm/ZI1M K/wdW3ngETxBmXoozzFMT89aEWIVR5/PFodWK1elekE9iJxACuR98Zg2QttTD3x8 A9w8VEyMLOXcDTrPFpHegMKswFBg5iuMulAdXAoGejWTI3n+qKFpabHm2Lfs6wjk 5rjucpTdeFK6UeWF1xAvNxXibuu5BlGwv53930qIXRwO/Gn2Rh5DXWxKU2fEIme/ xgQQmIsDeUoWbfybdjw/x7Q0LW4mINiLDQcGHHRQKFIxbAJCT3USPLGh5xwE9/Er ABEBAAGJAR8EGAECAAkFAlYy4RYCGwwACgkQiKUE3BPJzW0uYAf9Hf30n8tM3mR2 Zo6ESE0ivgdgjaJtAWrBUx7JzAzPjBnBOlNnu5Y9lVEqetvUPH6e3PvaHYUuaUU8 0HwxuKBW9nUprgV6uIu1DZmlcp+SxpbuCy7RDpNocRLNWWFMaYYzznmTgfnTgD4D gCq8Mf1mcfrluTkOAo+QNqbMfl1GISClopRqxVuAo59ewgMnFujwgd8w12BwWl24 CzqOs5HqcUslePj+LzcjSNgVCklYwKl+0dsb/fctMOCtHodwqm2CBJ+zydvNmYkD fxda/J91Z1xrah5ec++FL0L4vs+jCiIWJeupJFKlr1hCMZiiGH7W554loK5l4jv3 EY347EidAw== =Ta4p -----END PGP PUBLIC KEY BLOCK-----
Reply subtree:
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>