While my sim is running, I can do all sorts of things. Grocery shop, prowl the web, take a nap. https://xkcd.com/303/ Same idea. My alternator simulator simulation (!) takes about 25 minutes to rev up, running 10 or so PPM of real time. It's nicely settled in about an hour.
Spice is great!
Started by ●August 16, 2023
Reply by ●August 16, 20232023-08-16
John Larkin <jlarkin@highland_atwork_technology.com> wrote:> > > While my sim is running, I can do all sorts of things. Grocery shop, > prowl the web, take a nap. > > https://xkcd.com/303/ > > Same idea. My alternator simulator simulation (!) takes about 25 > minutes to rev up, running 10 or so PPM of real time. It's nicely > settled in about an hour. > >It’s probably pretty linear, so you could solve the DE by hand. Then you’d have more info than a stack of sims. But then your fencing would suffer. ;) Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics
Reply by ●August 17, 20232023-08-17
On Thu, 17 Aug 2023 00:11:11 -0000 (UTC), Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:>John Larkin <jlarkin@highland_atwork_technology.com> wrote: >> >> >> While my sim is running, I can do all sorts of things. Grocery shop, >> prowl the web, take a nap. >> >> https://xkcd.com/303/ >> >> Same idea. My alternator simulator simulation (!) takes about 25 >> minutes to rev up, running 10 or so PPM of real time. It's nicely >> settled in about an hour. >> >> > >It�s probably pretty linear, so you could solve the DE by hand. Then you�d >have more info than a stack of sims.It's a mess of PWM modulators, mosfet half-bridges, cycle-by-cycle current limiters, 3-phase common-mode chokes, ferrite beads, about 50 bypass caps. I'm not smart enough to do that analytically. The sim includes the FADEC power supply, which rectifies the 3-phase alternator output and shorts it when the DC voltage gets too high. What a mess: I have the simlated alternator frequency, some low KHz. The PWM driver stage at 250 KHz. And the simulated FADEC which PWM shorts my fake alternator at about 30 KHz, when it feels like. This represents the load that I'm driving, what I imagine a FADEC power supply might do. PM alternators don't mind being shorted. https://www.dropbox.com/scl/fi/lk0p4dj4a9dtlw1b2kh6r/Fadec_Box.jpg?rlkey=1hsxoak5xc32ul3ymdb06oh12&raw=1 It's under 10% of the total sim schematic.> >But then your fencing would suffer. ;)My brain would explode. Spice avoids a lot of hard thinking.> >Cheers > >Phil Hobbs
Reply by ●August 17, 20232023-08-17
On Thursday, August 17, 2023 at 6:47:11 AM UTC-4, John Larkin wrote:> On Thu, 17 Aug 2023 00:11:11 -0000 (UTC), Phil Hobbs > <pcdhSpamM...@electrooptical.net> wrote: > > >John Larkin <jlarkin@highland_atwork_technology.com> wrote: > >> > >> > >> While my sim is running, I can do all sorts of things. Grocery shop, > >> prowl the web, take a nap. > >> > >> https://xkcd.com/303/ > >> > >> Same idea. My alternator simulator simulation (!) takes about 25 > >> minutes to rev up, running 10 or so PPM of real time. It's nicely > >> settled in about an hour. > >> > >> > > > >It’s probably pretty linear, so you could solve the DE by hand. Then you’d > >have more info than a stack of sims. > It's a mess of PWM modulators, mosfet half-bridges, cycle-by-cycle > current limiters, 3-phase common-mode chokes, ferrite beads, about 50 > bypass caps. I'm not smart enough to do that analytically.Unless all those subelements interact, it's insane to simulate the whole shebang at once.> > The sim includes the FADEC power supply, which rectifies the 3-phase > alternator output and shorts it when the DC voltage gets too high. > > What a mess: I have the simlated alternator frequency, some low KHz. > The PWM driver stage at 250 KHz. And the simulated FADEC which PWM > shorts my fake alternator at about 30 KHz, when it feels like. > > This represents the load that I'm driving, what I imagine a FADEC > power supply might do. PM alternators don't mind being shorted. > > https://www.dropbox.com/scl/fi/lk0p4dj4a9dtlw1b2kh6r/Fadec_Box.jpg?rlkey=1hsxoak5xc32ul3ymdb06oh12&raw=1 > > It's under 10% of the total sim schematic. > > > >But then your fencing would suffer. ;) > My brain would explode. Spice avoids a lot of hard thinking. > > > > > >Cheers > > > >Phil Hobbs
Reply by ●August 17, 20232023-08-17
On a sunny day (Thu, 17 Aug 2023 06:18:11 -0700 (PDT)) it happened Fred Bloggs <bloggs.fredbloggs.fred@gmail.com> wrote in <6e59a97a-a0a5-4176-a4c8-199e60a5edc6n@googlegroups.com>:>On Thursday, August 17, 2023 at 6:47:11 AM UTC-4, John Larkin wrote= >: >> On Thu, 17 Aug 2023 00:11:11 -0000 (UTC), Phil Hobbs >> <pcdhSpamM...@electrooptical.net> wrote: >> >> >John Larkin <jlarkin@highland_atwork_technology.com> wrote: >> >> >> >> >> >> While my sim is running, I can do all sorts of things. Grocery shop,= > >> >> prowl the web, take a nap. >> >> >> >> https://xkcd.com/303/ >> >> >> >> Same idea. My alternator simulator simulation (!) takes about 25 >> >> minutes to rev up, running 10 or so PPM of real time. It's nicely >> >> settled in about an hour. >> >> >> >> >> > >> >It’s probably pretty linear, so you could solve the DE by hand. = >Then you’d >> >have more info than a stack of sims. >> It's a mess of PWM modulators, mosfet half-bridges, cycle-by-cycle >> current limiters, 3-phase common-mode chokes, ferrite beads, about 50 >> bypass caps. I'm not smart enough to do that analytically. > >Unless all those subelements interact, it's insane to simulate the whole sh= >ebang at once.Spice has little differences from reality in its models. The bigger the thing the more those errors will have an effect, likely increasing exponential. To the point of chaos theory where one butterfly wing flapping can create glowball worming. I looked at the circuit diagram (from J.L.) and I think I can see what it is supposed to do. But its incomplete so ... It is gonna need a lot of real testing no matter what that spice says. I am sure John L knows that.
Reply by ●August 17, 20232023-08-17
On Thu, 17 Aug 2023 06:18:11 -0700 (PDT), Fred Bloggs <bloggs.fredbloggs.fred@gmail.com> wrote:>On Thursday, August 17, 2023 at 6:47:11?AM UTC-4, John Larkin wrote: >> On Thu, 17 Aug 2023 00:11:11 -0000 (UTC), Phil Hobbs >> <pcdhSpamM...@electrooptical.net> wrote: >> >> >John Larkin <jlarkin@highland_atwork_technology.com> wrote: >> >> >> >> >> >> While my sim is running, I can do all sorts of things. Grocery shop, >> >> prowl the web, take a nap. >> >> >> >> https://xkcd.com/303/ >> >> >> >> Same idea. My alternator simulator simulation (!) takes about 25 >> >> minutes to rev up, running 10 or so PPM of real time. It's nicely >> >> settled in about an hour. >> >> >> >> >> > >> >It�s probably pretty linear, so you could solve the DE by hand. Then you�d >> >have more info than a stack of sims. >> It's a mess of PWM modulators, mosfet half-bridges, cycle-by-cycle >> current limiters, 3-phase common-mode chokes, ferrite beads, about 50 >> bypass caps. I'm not smart enough to do that analytically. > >Unless all those subelements interact, it's insane to simulate the whole shebang at once.Of course they interact! The 200 watt floating dc/dc conveter is reasonably independent so that's a separate sim. Ditto my soft-start circuit that ramps up the raw 48v bus in to the dc/dc. High school trig was some time ago, so I have a couple of sims to verify the basic 3-phase math. Spice could eventually destroy all our math skills; I use it for voltage dividers and RC timing circuits too. Is there an anlytical way to express delay lines? I think I saw the delay case once, in a test for PE registration as a Controls Engineer.
Reply by ●August 17, 20232023-08-17
On Thu, 17 Aug 2023 14:40:07 GMT, Jan Panteltje <alien@comet.invalid> wrote:>On a sunny day (Thu, 17 Aug 2023 06:18:11 -0700 (PDT)) it happened Fred Bloggs ><bloggs.fredbloggs.fred@gmail.com> wrote in ><6e59a97a-a0a5-4176-a4c8-199e60a5edc6n@googlegroups.com>: > >>On Thursday, August 17, 2023 at 6:47:11 AM UTC-4, John Larkin wrote= >>: >>> On Thu, 17 Aug 2023 00:11:11 -0000 (UTC), Phil Hobbs >>> <pcdhSpamM...@electrooptical.net> wrote: >>> >>> >John Larkin <jlarkin@highland_atwork_technology.com> wrote: >>> >> >>> >> >>> >> While my sim is running, I can do all sorts of things. Grocery shop,= >> >>> >> prowl the web, take a nap. >>> >> >>> >> https://xkcd.com/303/ >>> >> >>> >> Same idea. My alternator simulator simulation (!) takes about 25 >>> >> minutes to rev up, running 10 or so PPM of real time. It's nicely >>> >> settled in about an hour. >>> >> >>> >> >>> > >>> >It’s probably pretty linear, so you could solve the DE by hand. = >>Then you’d >>> >have more info than a stack of sims. >>> It's a mess of PWM modulators, mosfet half-bridges, cycle-by-cycle >>> current limiters, 3-phase common-mode chokes, ferrite beads, about 50 >>> bypass caps. I'm not smart enough to do that analytically. >> >>Unless all those subelements interact, it's insane to simulate the whole sh= >>ebang at once. > >Spice has little differences from reality in its models. >The bigger the thing the more those errors will have an effect, >likely increasing exponential. >To the point of chaos theory where one butterfly wing flapping can create glowball worming. > >I looked at the circuit diagram (from J.L.) and I think I can see what it is supposed to do. >But its incomplete so ... >It is gonna need a lot of real testing no matter what that spice says. >I am sure John L knows that.We already sell an alternator simulator, a big rackmount thing with a big isolation transformer per phase. The new one is much smaller, a single board, and doesn't have room for transformers, so it's three half-bridges riding on the floating three-phase N node. I trust the sim as regards the big-picture theory. The older one worked as simulated, except for some TI class-D amps blowing up, which we couldn't have simulated. We'll build the FADEC regulator as a proto board so we can test things in real life.
Reply by ●August 17, 20232023-08-17
John Larkin <jlarkin@highlandSNIPMEtechnology.com> wrote:> On Thu, 17 Aug 2023 06:18:11 -0700 (PDT), Fred Bloggs > <bloggs.fredbloggs.fred@gmail.com> wrote: > >> On Thursday, August 17, 2023 at 6:47:11?AM UTC-4, John Larkin wrote: >>> On Thu, 17 Aug 2023 00:11:11 -0000 (UTC), Phil Hobbs >>> <pcdhSpamM...@electrooptical.net> wrote: >>> >>>> John Larkin <jlarkin@highland_atwork_technology.com> wrote: >>>>> >>>>> >>>>> While my sim is running, I can do all sorts of things. Grocery shop, >>>>> prowl the web, take a nap. >>>>> >>>>> https://xkcd.com/303/ >>>>> >>>>> Same idea. My alternator simulator simulation (!) takes about 25 >>>>> minutes to rev up, running 10 or so PPM of real time. It's nicely >>>>> settled in about an hour. >>>>> >>>>> >>>> >>>> It’s probably pretty linear, so you could solve the DE by hand. Then you’d >>>> have more info than a stack of sims. >>> It's a mess of PWM modulators, mosfet half-bridges, cycle-by-cycle >>> current limiters, 3-phase common-mode chokes, ferrite beads, about 50 >>> bypass caps. I'm not smart enough to do that analytically. >> >> Unless all those subelements interact, it's insane to simulate the whole shebang at once. > > Of course they interact! > > The 200 watt floating dc/dc conveter is reasonably independent so > that's a separate sim. Ditto my soft-start circuit that ramps up the > raw 48v bus in to the dc/dc. > > High school trig was some time ago, so I have a couple of sims to > verify the basic 3-phase math. Spice could eventually destroy all our > math skills; I use it for voltage dividers and RC timing circuits too. > > Is there an anlytical way to express delay lines? I think I saw the > delay case once, in a test for PE registration as a Controls Engineer. > >H(f) = exp(-j 2 pi f tau) Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics
Reply by ●August 17, 20232023-08-17
On Friday, August 18, 2023 at 1:04:11 AM UTC+10, John Larkin wrote:> On Thu, 17 Aug 2023 06:18:11 -0700 (PDT), Fred Bloggs > <bloggs.fred...@gmail.com> wrote: > >On Thursday, August 17, 2023 at 6:47:11?AM UTC-4, John Larkin wrote: > >> On Thu, 17 Aug 2023 00:11:11 -0000 (UTC), Phil Hobbs > >> <pcdhSpamM...@electrooptical.net> wrote: > >> > >> >John Larkin <jlarkin@highland_atwork_technology.com> wrote:<snip>> Is there an analytical way to express delay lines? I think I saw the delay case once, in a test for PE registration as a Controls Engineer.Of course there is. Williams and Taylor (ISBN 0 -07-070434-1) tell you how to build linear phase low pass and all-pass filters, which is to say structures which offer a constant delay over a range of frequencies, and they give you the analytic forms of these filters. -- Bill Sloman, Sydney
Reply by ●August 17, 20232023-08-17
On Thu, 17 Aug 2023 15:36:39 -0000 (UTC), Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:>John Larkin <jlarkin@highlandSNIPMEtechnology.com> wrote: >> On Thu, 17 Aug 2023 06:18:11 -0700 (PDT), Fred Bloggs >> <bloggs.fredbloggs.fred@gmail.com> wrote: >> >>> On Thursday, August 17, 2023 at 6:47:11?AM UTC-4, John Larkin wrote: >>>> On Thu, 17 Aug 2023 00:11:11 -0000 (UTC), Phil Hobbs >>>> <pcdhSpamM...@electrooptical.net> wrote: >>>> >>>>> John Larkin <jlarkin@highland_atwork_technology.com> wrote: >>>>>> >>>>>> >>>>>> While my sim is running, I can do all sorts of things. Grocery shop, >>>>>> prowl the web, take a nap. >>>>>> >>>>>> https://xkcd.com/303/ >>>>>> >>>>>> Same idea. My alternator simulator simulation (!) takes about 25 >>>>>> minutes to rev up, running 10 or so PPM of real time. It's nicely >>>>>> settled in about an hour. >>>>>> >>>>>> >>>>> >>>>> It?s probably pretty linear, so you could solve the DE by hand. Then you?d >>>>> have more info than a stack of sims. >>>> It's a mess of PWM modulators, mosfet half-bridges, cycle-by-cycle >>>> current limiters, 3-phase common-mode chokes, ferrite beads, about 50 >>>> bypass caps. I'm not smart enough to do that analytically. >>> >>> Unless all those subelements interact, it's insane to simulate the whole shebang at once. >> >> Of course they interact! >> >> The 200 watt floating dc/dc conveter is reasonably independent so >> that's a separate sim. Ditto my soft-start circuit that ramps up the >> raw 48v bus in to the dc/dc. >> >> High school trig was some time ago, so I have a couple of sims to >> verify the basic 3-phase math. Spice could eventually destroy all our >> math skills; I use it for voltage dividers and RC timing circuits too. >> >> Is there an anlytical way to express delay lines? I think I saw the >> delay case once, in a test for PE registration as a Controls Engineer. >> >> > >H(f) = exp(-j 2 pi f tau)Yes, but I think he means the Telegrapher's Equations: .<https://en.wikipedia.org/wiki/Telegrapher%27s_equations> Joe Gwinn
