On Sunday, 2 January 2022 at 18:19:00 UTC+1, legg wrote:
> On Sat, 1 Jan 2022 17:38:31 -0800 (PST), Anthony William Sloman
> <bill....@ieee.org> wrote:
>
> <snip>
> >> > Physical iteration may still be the fastest way to implimentation for a practical app, though a pencil and paper can cut this work down.
> >> >The simulation just eats man-hours.
> >
> >A lot less than building the hardware. It's good for getting rid of ideas that can't work, but it isn't a reliable way of working out whether real hardware will work.
> >
> >> Spice is great. It lets a person play with ideas quickly, explore
> >> hunches, get quantitative with the things that look promising.
> >
> >But only to the extent to which the simulation is realisitic. An inductor winding without any parallel capacitance isn't. For a single layer winding 1pF of parallel capacitance is sort of realistic. Multilayer winding need more.
> Unless it's a saturating core model, miniaturization and
> minimalization efforts will be misleading.
>
> As L values reduce, inductive strays also become important,
> as do recovery times in the semiconductors of the transmitting
> and receiving structures, when impressed with below-ground
> or above rail transients or reflected emf.
>
> The physical dimensions of beads and insulated wire create
> clusters of performance features that have sometimes been
> spelled out quite effectively, in millimeters, in patents.
>
> I expect it's much the same for the integrated case, given
> the limited types of core matl and dimensional constraints
> present.
>
> Even more so, if there's no core material.
>
The digital isolators has the advantage of using oxide layer as isolation, so they can couple well. And all the advantages of ASICs with lots of free transistors to cope with parasitic annoyances

On Sunday, 2 January 2022 at 18:48:05 UTC+1, jla...@highlandsniptechnology.com wrote:
> On Sun, 02 Jan 2022 17:54:15 +0100, Klaus Kragelund
> <klau...@hotmail.com> wrote:
>
> >02.01.22 16:29, jla...@highlandsniptechnology.com wrote:
> >>On Sun, 02 Jan 2022 10:09:25 +0100, Klaus Kragelund
> >><klau...@hotmail.com> wrote:
> >>
> >>>02.01.22 02:38, Anthony William Sloman wrote:
> >>>>On Sunday, January 2, 2022 at 7:45:52 AM UTC+11, jla...@highlandsniptechnology.com wrote:
> >>>>> On Sat, 01 Jan 2022 13:45:00 -0500, legg <le...@nospam.magma.ca> wrote:
> >>>>>
> >>>>> >On Sat, 1 Jan 2022 04:01:57 -0800 (PST), Anthony William Sloman
> >>>>> ><bill....@ieee.org> wrote:
> >>>>> >
> >>>>> >>On Saturday, January 1, 2022 at 12:43:32 PM UTC+11, jla...@highlandsniptechnology.com wrote:
> >>>>> >>> On Fri, 31 Dec 2021 20:21:16 -0500, legg <le...@nospam.magma.ca> wrote:
> >>>>> >>> >On Fri, 31 Dec 2021 09:23:48 -0800, jla...@highlandsniptechnology.com wrote:
> >>>>> >>> >>On Fri, 31 Dec 2021 11:38:25 -0500, legg <le...@nospam.magma.ca> wrote:
> >>>>> >>> >>>On Thu, 30 Dec 2021 19:05:06 -0800 (PST), Anthony William Sloman <bill....@ieee.org> wrote:
> >>>>> >>> >>>>On Friday, December 31, 2021 at 5:21:07 AM UTC+11, John Larkin wrote:
> >>>>> >>> >>>>> On Thu, 30 Dec 2021 09:08:03 -0500, legg <le...@nospam.magma.ca> wrote:
> >>>>> >>> >>>>>
> >>>>> >>> >>>>> >On Thu, 30 Dec 2021 19:04:22 +1100, Sylvia Else <syl...@email.invalid>
> >>>>> >>> >>>>> >wrote:
> >>>>> >>> >>>>> >
> >>>>> >>> >>>>> >>On 30-Dec-21 4:11 pm, jla...@highlandsniptechnology.com wrote:
> >>>>> >>> >>>>> >>> Version 4
> >>>>> >>> >>>>> >>
> >>>>> >>> >>>>> >><snip>
> >>>>> >>> >>>>> >>
> >>>>> >>> >>>>> >>What is the use-case for this that a conventional digital isolator
> >>>>> >>> >>>>> >>wouldn't be suitable for?
> >>>>> >>> >>>>> >
> >>>>> >>> >>>>> >Sometimes used in lower frequency isolated gate drive, when minimal
> >>>>> >>> >>>>> >magnetics cost is the aim.
> >>>>> >>> >>>>>
> >>>>> >>> >>>>> It's faster than most isolators, and is DC-coupled, after a power-up
> >>>>> >>> >>>>> priming shot.
> >>>>> >>> >>>>
> >>>>> >>> >>>>Not a claim that's worth making for a purely theoretical transformer driving an LT Spice generic Schmitt trigger.
> >>>>> >>> >>>>
> >>>>> >>> >>>>No parallel capacitance across either inductor, and no current induced in the transformer core - it's a little too theoretical too swank about.
> >>>>> >>> >>>>
> >>>>> >>> >>>>It worked fine when I did it in 1979, but I wasn't around to see it go into production (if it did).
> >>>>> >>> >>>
> >>>>> >>> >>>Getting the model to act like the real thing takes time and effort.
> >>>>> >>> >>>
> >>>>> >>> >>>Getting the real thing to act like the model is probably delusional.
> >>>>> >>> >>
> >>>>> >>> >>Right, it's best to avoid designing any electronics. It's too hard and
> >>>>> >>> >>too risky.
> >>>>> >>> >
> >>>>> >>> >Hey! The model works! What's HIS problem . . . ?
> >>>>> >>>
> >>>>> >>> Do you mean Sloman?
> >>>>> >>
> >>>>> >>Legg was responding to one of your posts, not mine.
> >>>>> >>
> >>>>> >>> He's the group leader on never actually doing anything.
> >>>>> >>
> >>>>> >>I'd got what you posted working with real parts back in 1979 - I'd already done it, so why would I need to do it again?
> >>>>> >>
> >>>>> >>> So naturally he finds reasons why nothing will work.
> >>>>> >>
> >>>>> >>I didn't say it wouldn't work - I just pointed out that the transformer model wasn't all that realistic, and neither was the Schmitt trigger.
> >>>>> >>
> >>>>> >>You could have done quite a bit better, and telling us what you had in mind to use for your transformer would have been a good start.
> >>>>> >
> >>>>> >Simulationss are useful in that they suggest what should or
> >>>>> >could work.
> >>>>> >
> >>>>> >If you limit it to a specific application, you can introduce
> >>>>> >realistic strays and likely operating conditions with increasingly
> >>>>> >more accurate models.
> >>>>> >
> >>>>> >The 'party trick' aspect of this circuit was the miniscule magnetic
> >>>>> >component that was possible - though reduction in actual cost shows
> >>>>> >diminishing and even reversing returns as you get carried away.
> >>>>
> >>>>When I cam up with my version of the circuit in 1979 this did strike me as the useful feature. I wasn't tempted to try and get it patented.
> >>>>
> >>>>> >An integrated magnetic component has been used in some places, though the isolation tended to be compromised.
> >>>>
> >>>>Integrating anything means realising it within very limited dimensions, and high voltage isolation needs big gaps.
> >>>>
> >>>Not really. Just needs to be solid. 0.4mm FR4 is approved reinforced. So spiral coils on either side of the PCB could work. In practical size, leakage inductance is high
> >>
> >>There are down-firing surface-mount leds and photodiodes. One could
> >>couple light through a board.
> >>
> >>Or e-fields, an FR4 capacitor based signal or power coupler.
> >>
> >>
> >>
> >I have done both the AM modulated transformer and the E field. Both tend to emit a lot of radiated noise, so you need to keep it to only transitions transmission
> >
> >Also, they can be subceptible to EMC burst
> >
> >LED method is clean, but slow
> With blind vias one could make a shielded capacitor!
>
> I should try some stacked stripline couplers on a future test board.
> Parts made of copper inside PCBs are free!
That would be very interesting to try out, for sure :-)

On Monday, 3 January 2022 at 10:29:23 UTC, klaus.k...@gmail.com wrote:
> On Sunday, 2 January 2022 at 18:48:05 UTC+1, jla...@highlandsniptechnology.com wrote:
> > On Sun, 02 Jan 2022 17:54:15 +0100, Klaus Kragelund
> > <klau...@hotmail.com> wrote:
> >
> > >02.01.22 16:29, jla...@highlandsniptechnology.com wrote:
> > >>On Sun, 02 Jan 2022 10:09:25 +0100, Klaus Kragelund
> > >><klau...@hotmail.com> wrote:
> > >>
> > >>>02.01.22 02:38, Anthony William Sloman wrote:
> > >>>>On Sunday, January 2, 2022 at 7:45:52 AM UTC+11, jla...@highlandsniptechnology.com wrote:
> > >>>>> On Sat, 01 Jan 2022 13:45:00 -0500, legg <le...@nospam.magma.ca> wrote:
> > >>>>>
> > >>>>> >On Sat, 1 Jan 2022 04:01:57 -0800 (PST), Anthony William Sloman
> > >>>>> ><bill....@ieee.org> wrote:
> > >>>>> >
> > >>>>> >>On Saturday, January 1, 2022 at 12:43:32 PM UTC+11, jla...@highlandsniptechnology.com wrote:
> > >>>>> >>> On Fri, 31 Dec 2021 20:21:16 -0500, legg <le...@nospam.magma.ca> wrote:
> > >>>>> >>> >On Fri, 31 Dec 2021 09:23:48 -0800, jla...@highlandsniptechnology.com wrote:
> > >>>>> >>> >>On Fri, 31 Dec 2021 11:38:25 -0500, legg <le...@nospam.magma.ca> wrote:
> > >>>>> >>> >>>On Thu, 30 Dec 2021 19:05:06 -0800 (PST), Anthony William Sloman <bill....@ieee.org> wrote:
> > >>>>> >>> >>>>On Friday, December 31, 2021 at 5:21:07 AM UTC+11, John Larkin wrote:
> > >>>>> >>> >>>>> On Thu, 30 Dec 2021 09:08:03 -0500, legg <le...@nospam.magma.ca> wrote:
> > >>>>> >>> >>>>>
> > >>>>> >>> >>>>> >On Thu, 30 Dec 2021 19:04:22 +1100, Sylvia Else <syl...@email.invalid>
> > >>>>> >>> >>>>> >wrote:
> > >>>>> >>> >>>>> >
> > >>>>> >>> >>>>> >>On 30-Dec-21 4:11 pm, jla...@highlandsniptechnology.com wrote:
> > >>>>> >>> >>>>> >>> Version 4
> > >>>>> >>> >>>>> >>
> > >>>>> >>> >>>>> >><snip>
> > >>>>> >>> >>>>> >>
> > >>>>> >>> >>>>> >>What is the use-case for this that a conventional digital isolator
> > >>>>> >>> >>>>> >>wouldn't be suitable for?
> > >>>>> >>> >>>>> >
> > >>>>> >>> >>>>> >Sometimes used in lower frequency isolated gate drive, when minimal
> > >>>>> >>> >>>>> >magnetics cost is the aim.
> > >>>>> >>> >>>>>
> > >>>>> >>> >>>>> It's faster than most isolators, and is DC-coupled, after a power-up
> > >>>>> >>> >>>>> priming shot.
> > >>>>> >>> >>>>
> > >>>>> >>> >>>>Not a claim that's worth making for a purely theoretical transformer driving an LT Spice generic Schmitt trigger.
> > >>>>> >>> >>>>
> > >>>>> >>> >>>>No parallel capacitance across either inductor, and no current induced in the transformer core - it's a little too theoretical too swank about.
> > >>>>> >>> >>>>
> > >>>>> >>> >>>>It worked fine when I did it in 1979, but I wasn't around to see it go into production (if it did).
> > >>>>> >>> >>>
> > >>>>> >>> >>>Getting the model to act like the real thing takes time and effort.
> > >>>>> >>> >>>
> > >>>>> >>> >>>Getting the real thing to act like the model is probably delusional.
> > >>>>> >>> >>
> > >>>>> >>> >>Right, it's best to avoid designing any electronics. It's too hard and
> > >>>>> >>> >>too risky.
> > >>>>> >>> >
> > >>>>> >>> >Hey! The model works! What's HIS problem . . . ?
> > >>>>> >>>
> > >>>>> >>> Do you mean Sloman?
> > >>>>> >>
> > >>>>> >>Legg was responding to one of your posts, not mine.
> > >>>>> >>
> > >>>>> >>> He's the group leader on never actually doing anything.
> > >>>>> >>
> > >>>>> >>I'd got what you posted working with real parts back in 1979 - I'd already done it, so why would I need to do it again?
> > >>>>> >>
> > >>>>> >>> So naturally he finds reasons why nothing will work.
> > >>>>> >>
> > >>>>> >>I didn't say it wouldn't work - I just pointed out that the transformer model wasn't all that realistic, and neither was the Schmitt trigger.
> > >>>>> >>
> > >>>>> >>You could have done quite a bit better, and telling us what you had in mind to use for your transformer would have been a good start.
> > >>>>> >
> > >>>>> >Simulationss are useful in that they suggest what should or
> > >>>>> >could work.
> > >>>>> >
> > >>>>> >If you limit it to a specific application, you can introduce
> > >>>>> >realistic strays and likely operating conditions with increasingly
> > >>>>> >more accurate models.
> > >>>>> >
> > >>>>> >The 'party trick' aspect of this circuit was the miniscule magnetic
> > >>>>> >component that was possible - though reduction in actual cost shows
> > >>>>> >diminishing and even reversing returns as you get carried away.
> > >>>>
> > >>>>When I cam up with my version of the circuit in 1979 this did strike me as the useful feature. I wasn't tempted to try and get it patented.
> > >>>>
> > >>>>> >An integrated magnetic component has been used in some places, though the isolation tended to be compromised.
> > >>>>
> > >>>>Integrating anything means realising it within very limited dimensions, and high voltage isolation needs big gaps.
> > >>>>
> > >>>Not really. Just needs to be solid. 0.4mm FR4 is approved reinforced. So spiral coils on either side of the PCB could work. In practical size, leakage inductance is high
> > >>
> > >>There are down-firing surface-mount leds and photodiodes. One could
> > >>couple light through a board.
> > >>
> > >>Or e-fields, an FR4 capacitor based signal or power coupler.
> > >>
> > >>
> > >>
> > >I have done both the AM modulated transformer and the E field. Both tend to emit a lot of radiated noise, so you need to keep it to only transitions transmission
> > >
> > >Also, they can be subceptible to EMC burst
> > >
> > >LED method is clean, but slow
> > With blind vias one could make a shielded capacitor!
> >
> > I should try some stacked stripline couplers on a future test board.
> > Parts made of copper inside PCBs are free!
> That would be very interesting to try out, for sure :-)

I've done something similar in a high-volume automotive product where
a pulsed infra-red diode (for the MOST bus) was producing excessive rf
emissions. It was not possible to place decoupling capacitors close
enough to the pins of the driver module because of keep-out rules for the
selective wave soldering of the module.
The solution was to build a multi-layer capacitor from alternating power
and ground planes directly under the device. It worked really well.
John

On Mon, 3 Jan 2022 02:28:39 -0800 (PST), Klaus Kragelund
<klaus.kragelund@gmail.com> wrote:

>On Sunday, 2 January 2022 at 18:19:00 UTC+1, legg wrote:
>> On Sat, 1 Jan 2022 17:38:31 -0800 (PST), Anthony William Sloman
>> <bill....@ieee.org> wrote:
>>
>> <snip>
>> >> > Physical iteration may still be the fastest way to implimentation for a practical app, though a pencil and paper can cut this work down.
>> >> >The simulation just eats man-hours.
>> >
>> >A lot less than building the hardware. It's good for getting rid of ideas that can't work, but it isn't a reliable way of working out whether real hardware will work.
>> >
>> >> Spice is great. It lets a person play with ideas quickly, explore
>> >> hunches, get quantitative with the things that look promising.
>> >
>> >But only to the extent to which the simulation is realisitic. An inductor winding without any parallel capacitance isn't. For a single layer winding 1pF of parallel capacitance is sort of realistic. Multilayer winding need more.
>> Unless it's a saturating core model, miniaturization and
>> minimalization efforts will be misleading.
>>
>> As L values reduce, inductive strays also become important,
>> as do recovery times in the semiconductors of the transmitting
>> and receiving structures, when impressed with below-ground
>> or above rail transients or reflected emf.
>>
>> The physical dimensions of beads and insulated wire create
>> clusters of performance features that have sometimes been
>> spelled out quite effectively, in millimeters, in patents.
>>
>> I expect it's much the same for the integrated case, given
>> the limited types of core matl and dimensional constraints
>> present.
>>
>> Even more so, if there's no core material.
>>
>The digital isolators has the advantage of using oxide layer as isolation, so they can couple well. And all the advantages of ASICs with lots of free transistors to cope with parasitic annoyances

I think the bulk of the commercially viable ones use differential
capacitive coupling for data, but there's all kinds, now. Many
ways to skin a cat.

RL

On Mon, 3 Jan 2022 04:09:09 -0800 (PST), John Walliker
<jrwalliker@gmail.com> wrote:

>On Monday, 3 January 2022 at 10:29:23 UTC, klaus.k...@gmail.com wrote:
>> On Sunday, 2 January 2022 at 18:48:05 UTC+1, jla...@highlandsniptechnology.com wrote:
>> > On Sun, 02 Jan 2022 17:54:15 +0100, Klaus Kragelund
>> > <klau...@hotmail.com> wrote:
>> >
>> > >02.01.22 16:29, jla...@highlandsniptechnology.com wrote:
>> > >>On Sun, 02 Jan 2022 10:09:25 +0100, Klaus Kragelund
>> > >><klau...@hotmail.com> wrote:
>> > >>
>> > >>>02.01.22 02:38, Anthony William Sloman wrote:
>> > >>>>On Sunday, January 2, 2022 at 7:45:52 AM UTC+11, jla...@highlandsniptechnology.com wrote:
>> > >>>>> On Sat, 01 Jan 2022 13:45:00 -0500, legg <le...@nospam.magma.ca> wrote:
>> > >>>>>
>> > >>>>> >On Sat, 1 Jan 2022 04:01:57 -0800 (PST), Anthony William Sloman
>> > >>>>> ><bill....@ieee.org> wrote:
>> > >>>>> >
>> > >>>>> >>On Saturday, January 1, 2022 at 12:43:32 PM UTC+11, jla...@highlandsniptechnology.com wrote:
>> > >>>>> >>> On Fri, 31 Dec 2021 20:21:16 -0500, legg <le...@nospam.magma.ca> wrote:
>> > >>>>> >>> >On Fri, 31 Dec 2021 09:23:48 -0800, jla...@highlandsniptechnology.com wrote:
>> > >>>>> >>> >>On Fri, 31 Dec 2021 11:38:25 -0500, legg <le...@nospam.magma.ca> wrote:
>> > >>>>> >>> >>>On Thu, 30 Dec 2021 19:05:06 -0800 (PST), Anthony William Sloman <bill....@ieee.org> wrote:
>> > >>>>> >>> >>>>On Friday, December 31, 2021 at 5:21:07 AM UTC+11, John Larkin wrote:
>> > >>>>> >>> >>>>> On Thu, 30 Dec 2021 09:08:03 -0500, legg <le...@nospam.magma.ca> wrote:
>> > >>>>> >>> >>>>>
>> > >>>>> >>> >>>>> >On Thu, 30 Dec 2021 19:04:22 +1100, Sylvia Else <syl...@email.invalid>
>> > >>>>> >>> >>>>> >wrote:
>> > >>>>> >>> >>>>> >
>> > >>>>> >>> >>>>> >>On 30-Dec-21 4:11 pm, jla...@highlandsniptechnology.com wrote:
>> > >>>>> >>> >>>>> >>> Version 4
>> > >>>>> >>> >>>>> >>
>> > >>>>> >>> >>>>> >><snip>
>> > >>>>> >>> >>>>> >>
>> > >>>>> >>> >>>>> >>What is the use-case for this that a conventional digital isolator
>> > >>>>> >>> >>>>> >>wouldn't be suitable for?
>> > >>>>> >>> >>>>> >
>> > >>>>> >>> >>>>> >Sometimes used in lower frequency isolated gate drive, when minimal
>> > >>>>> >>> >>>>> >magnetics cost is the aim.
>> > >>>>> >>> >>>>>
>> > >>>>> >>> >>>>> It's faster than most isolators, and is DC-coupled, after a power-up
>> > >>>>> >>> >>>>> priming shot.
>> > >>>>> >>> >>>>
>> > >>>>> >>> >>>>Not a claim that's worth making for a purely theoretical transformer driving an LT Spice generic Schmitt trigger.
>> > >>>>> >>> >>>>
>> > >>>>> >>> >>>>No parallel capacitance across either inductor, and no current induced in the transformer core - it's a little too theoretical too swank about.
>> > >>>>> >>> >>>>
>> > >>>>> >>> >>>>It worked fine when I did it in 1979, but I wasn't around to see it go into production (if it did).
>> > >>>>> >>> >>>
>> > >>>>> >>> >>>Getting the model to act like the real thing takes time and effort.
>> > >>>>> >>> >>>
>> > >>>>> >>> >>>Getting the real thing to act like the model is probably delusional.
>> > >>>>> >>> >>
>> > >>>>> >>> >>Right, it's best to avoid designing any electronics. It's too hard and
>> > >>>>> >>> >>too risky.
>> > >>>>> >>> >
>> > >>>>> >>> >Hey! The model works! What's HIS problem . . . ?
>> > >>>>> >>>
>> > >>>>> >>> Do you mean Sloman?
>> > >>>>> >>
>> > >>>>> >>Legg was responding to one of your posts, not mine.
>> > >>>>> >>
>> > >>>>> >>> He's the group leader on never actually doing anything.
>> > >>>>> >>
>> > >>>>> >>I'd got what you posted working with real parts back in 1979 - I'd already done it, so why would I need to do it again?
>> > >>>>> >>
>> > >>>>> >>> So naturally he finds reasons why nothing will work.
>> > >>>>> >>
>> > >>>>> >>I didn't say it wouldn't work - I just pointed out that the transformer model wasn't all that realistic, and neither was the Schmitt trigger.
>> > >>>>> >>
>> > >>>>> >>You could have done quite a bit better, and telling us what you had in mind to use for your transformer would have been a good start.
>> > >>>>> >
>> > >>>>> >Simulationss are useful in that they suggest what should or
>> > >>>>> >could work.
>> > >>>>> >
>> > >>>>> >If you limit it to a specific application, you can introduce
>> > >>>>> >realistic strays and likely operating conditions with increasingly
>> > >>>>> >more accurate models.
>> > >>>>> >
>> > >>>>> >The 'party trick' aspect of this circuit was the miniscule magnetic
>> > >>>>> >component that was possible - though reduction in actual cost shows
>> > >>>>> >diminishing and even reversing returns as you get carried away.
>> > >>>>
>> > >>>>When I cam up with my version of the circuit in 1979 this did strike me as the useful feature. I wasn't tempted to try and get it patented.
>> > >>>>
>> > >>>>> >An integrated magnetic component has been used in some places, though the isolation tended to be compromised.
>> > >>>>
>> > >>>>Integrating anything means realising it within very limited dimensions, and high voltage isolation needs big gaps.
>> > >>>>
>> > >>>Not really. Just needs to be solid. 0.4mm FR4 is approved reinforced. So spiral coils on either side of the PCB could work. In practical size, leakage inductance is high
>> > >>
>> > >>There are down-firing surface-mount leds and photodiodes. One could
>> > >>couple light through a board.
>> > >>
>> > >>Or e-fields, an FR4 capacitor based signal or power coupler.
>> > >>
>> > >>
>> > >>
>> > >I have done both the AM modulated transformer and the E field. Both tend to emit a lot of radiated noise, so you need to keep it to only transitions transmission
>> > >
>> > >Also, they can be subceptible to EMC burst
>> > >
>> > >LED method is clean, but slow
>> > With blind vias one could make a shielded capacitor!
>> >
>> > I should try some stacked stripline couplers on a future test board.
>> > Parts made of copper inside PCBs are free!
>> That would be very interesting to try out, for sure :-)

I sometimes want a differentiator to make a fast edge into a pretty
gaussian pulse. That might be done with coupled striplines. Or make
the isolator transformer!

On 01/01/2022 17:21, jlarkin@highlandsniptechnology.com wrote:
> I like the nice cheap surface-mount dual inductors, the DRQ74 types.
> No CT. They have near zero leakage inductance.
>

Near zero leakage inductance but gobs of capacitance!

piglet

On Mon, 3 Jan 2022 16:45:37 +0000, Piglet <erichpwagner@hotmail.com>
wrote:

>On 01/01/2022 17:21, jlarkin@highlandsniptechnology.com wrote:
>> I like the nice cheap surface-mount dual inductors, the DRQ74 types.
>> No CT. They have near zero leakage inductance.
>>
>
>Near zero leakage inductance but gobs of capacitance!
>
>piglet
>
>
>
>

They are very nice parts, DRQ74 to DRQ127, but of course you have to
understand them to use them. A lot of parts are annoying that way.

They make cool HV power supplies. I like using one as a flyboost
(drive the ct in flyback mode and get 2x out) followed by a C-W
multiplier.

--

I yam what I yam - Popeye

On 02/01/2022 13.05, Anthony William Sloman wrote:
> On Sunday, January 2, 2022 at 8:09:33 PM UTC+11, Klaus Kragelund wrote:
>> 02.01.22 02:38, Anthony William Sloman wrote:
>>> On Sunday, January 2, 2022 at 7:45:52 AM UTC+11, jla...@highlandsniptechnology.com wrote:
>>>> On Sat, 01 Jan 2022 13:45:00 -0500, legg <le...@nospam.magma.ca> wrote:
>>>>
>>>>> On Sat, 1 Jan 2022 04:01:57 -0800 (PST), Anthony William Sloman
>>>>> <bill....@ieee.org> wrote:
>>>>>
>>>>>> On Saturday, January 1, 2022 at 12:43:32 PM UTC+11, jla...@highlandsniptechnology.com wrote:
>>>>>>> On Fri, 31 Dec 2021 20:21:16 -0500, legg <le...@nospam.magma.ca> wrote:
>>>>>>>> On Fri, 31 Dec 2021 09:23:48 -0800, jla...@highlandsniptechnology.com wrote:
>>>>>>>>> On Fri, 31 Dec 2021 11:38:25 -0500, legg <le...@nospam.magma.ca> wrote:
>>>>>>>>>> On Thu, 30 Dec 2021 19:05:06 -0800 (PST), Anthony William Sloman <bill....@ieee.org> wrote:
>>>>>>>>>>> On Friday, December 31, 2021 at 5:21:07 AM UTC+11, John Larkin wrote:
>>>>>>>>>>>> On Thu, 30 Dec 2021 09:08:03 -0500, legg <le...@nospam.magma.ca> wrote:
>>>>>>>>>>>>
>>>>>>>>>>>>> On Thu, 30 Dec 2021 19:04:22 +1100, Sylvia Else <syl...@email.invalid>
>>>>>>>>>>>>> wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>>> On 30-Dec-21 4:11 pm, jla...@highlandsniptechnology.com wrote:
>>>>>>>>>>>>>>> Version 4
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> <snip>
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> What is the use-case for this that a conventional digital isolator
>>>>>>>>>>>>>> wouldn't be suitable for?
>>>>>>>>>>>>>
>>>>>>>>>>>>> Sometimes used in lower frequency isolated gate drive, when minimal
>>>>>>>>>>>>> magnetics cost is the aim.
>>>>>>>>>>>>
>>>>>>>>>>>> It's faster than most isolators, and is DC-coupled, after a power-up
>>>>>>>>>>>> priming shot.
>>>>>>>>>>>
>>>>>>>>>>> Not a claim that's worth making for a purely theoretical transformer driving an LT Spice generic Schmitt trigger.
>>>>>>>>>>>
>>>>>>>>>>> No parallel capacitance across either inductor, and no current induced in the transformer core - it's a little too theoretical too swank about.
>>>>>>>>>>>
>>>>>>>>>>> It worked fine when I did it in 1979, but I wasn't around to see it go into production (if it did).
>>>>>>>>>>
>>>>>>>>>> Getting the model to act like the real thing takes time and effort.
>>>>>>>>>>
>>>>>>>>>> Getting the real thing to act like the model is probably delusional.
>>>>>>>>>
>>>>>>>>> Right, it's best to avoid designing any electronics. It's too hard and
>>>>>>>>> too risky.
>>>>>>>>
>>>>>>>> Hey! The model works! What's HIS problem . . . ?
>>>>>>>
>>>>>>> Do you mean Sloman?
>>>>>>
>>>>>> Legg was responding to one of your posts, not mine.
>>>>>>
>>>>>>> He's the group leader on never actually doing anything.
>>>>>>
>>>>>> I'd got what you posted working with real parts back in 1979 - I'd already done it, so why would I need to do it again?
>>>>>>
>>>>>>> So naturally he finds reasons why nothing will work.
>>>>>>
>>>>>> I didn't say it wouldn't work - I just pointed out that the transformer model wasn't all that realistic, and neither was the Schmitt trigger.
>>>>>>
>>>>>> You could have done quite a bit better, and telling us what you had in mind to use for your transformer would have been a good start.
>>>>>
>>>>> Simulationss are useful in that they suggest what should or
>>>>> could work.
>>>>>
>>>>> If you limit it to a specific application, you can introduce
>>>>> realistic strays and likely operating conditions with increasingly
>>>>> more accurate models.
>>>>>
>>>>> The 'party trick' aspect of this circuit was the miniscule magnetic
>>>>> component that was possible - though reduction in actual cost shows
>>>>> diminishing and even reversing returns as you get carried away.
>>>
>>> When I cam up with my version of the circuit in 1979 this did strike me as the useful feature. I wasn't tempted to try and get it patented.
>>>
>>>>> An integrated magnetic component has been used in some places, though the isolation tended to be compromised.
>>>
>>> Integrating anything means realising it within very limited dimensions, and high voltage isolation needs big gaps.
>>>
>> Not really. Just needs to be solid. 0.4mm FR4 is approved reinforced. So spiral coils on either side of the PCB could work. In practical size, leakage inductance is high
>
> Integration is usually taken to be putting stuff together on a silicon substrate (or GaAs or some other kind of semi-conductor). Anything that gets soldered onto FR4 creates an assembled device, not an integrated part.
>
That's your definition. If I integrate a coil into a PCB with no added
components, I would call that.... integrated ;-)

> Alumina would probably be a better high voltage substrate than FR4-epoxy bonded fibre-glass, but arcs have a nasty way of tracking across insulators.

Not practical for a PCB. Mixing alumina and FR4 makes it very expensive

On 03/01/2022 13.09, John Walliker wrote:
> On Monday, 3 January 2022 at 10:29:23 UTC, klaus.k...@gmail.com wrote:
>> On Sunday, 2 January 2022 at 18:48:05 UTC+1, jla...@highlandsniptechnology.com wrote:
>>> On Sun, 02 Jan 2022 17:54:15 +0100, Klaus Kragelund
>>> <klau...@hotmail.com> wrote:
>>>
>>>> 02.01.22 16:29, jla...@highlandsniptechnology.com wrote:
>>>>> On Sun, 02 Jan 2022 10:09:25 +0100, Klaus Kragelund
>>>>> <klau...@hotmail.com> wrote:
>>>>>
>>>>>> 02.01.22 02:38, Anthony William Sloman wrote:
>>>>>>> On Sunday, January 2, 2022 at 7:45:52 AM UTC+11, jla...@highlandsniptechnology.com wrote:
>>>>>>>> On Sat, 01 Jan 2022 13:45:00 -0500, legg <le...@nospam.magma.ca> wrote:
>>>>>>>>
>>>>>>>>> On Sat, 1 Jan 2022 04:01:57 -0800 (PST), Anthony William Sloman
>>>>>>>>> <bill....@ieee.org> wrote:
>>>>>>>>>
>>>>>>>>>> On Saturday, January 1, 2022 at 12:43:32 PM UTC+11, jla...@highlandsniptechnology.com wrote:
>>>>>>>>>>> On Fri, 31 Dec 2021 20:21:16 -0500, legg <le...@nospam.magma.ca> wrote:
>>>>>>>>>>>> On Fri, 31 Dec 2021 09:23:48 -0800, jla...@highlandsniptechnology.com wrote:
>>>>>>>>>>>>> On Fri, 31 Dec 2021 11:38:25 -0500, legg <le...@nospam.magma.ca> wrote:
>>>>>>>>>>>>>> On Thu, 30 Dec 2021 19:05:06 -0800 (PST), Anthony William Sloman <bill....@ieee.org> wrote:
>>>>>>>>>>>>>>> On Friday, December 31, 2021 at 5:21:07 AM UTC+11, John Larkin wrote:
>>>>>>>>>>>>>>>> On Thu, 30 Dec 2021 09:08:03 -0500, legg <le...@nospam.magma.ca> wrote:
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> On Thu, 30 Dec 2021 19:04:22 +1100, Sylvia Else <syl...@email.invalid>
>>>>>>>>>>>>>>>>> wrote:
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> On 30-Dec-21 4:11 pm, jla...@highlandsniptechnology.com wrote:
>>>>>>>>>>>>>>>>>>> Version 4
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> <snip>
>>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>>> What is the use-case for this that a conventional digital isolator
>>>>>>>>>>>>>>>>>> wouldn't be suitable for?
>>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>>> Sometimes used in lower frequency isolated gate drive, when minimal
>>>>>>>>>>>>>>>>> magnetics cost is the aim.
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> It's faster than most isolators, and is DC-coupled, after a power-up
>>>>>>>>>>>>>>>> priming shot.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Not a claim that's worth making for a purely theoretical transformer driving an LT Spice generic Schmitt trigger.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> No parallel capacitance across either inductor, and no current induced in the transformer core - it's a little too theoretical too swank about.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> It worked fine when I did it in 1979, but I wasn't around to see it go into production (if it did).
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Getting the model to act like the real thing takes time and effort.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Getting the real thing to act like the model is probably delusional.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Right, it's best to avoid designing any electronics. It's too hard and
>>>>>>>>>>>>> too risky.
>>>>>>>>>>>>
>>>>>>>>>>>> Hey! The model works! What's HIS problem . . . ?
>>>>>>>>>>>
>>>>>>>>>>> Do you mean Sloman?
>>>>>>>>>>
>>>>>>>>>> Legg was responding to one of your posts, not mine.
>>>>>>>>>>
>>>>>>>>>>> He's the group leader on never actually doing anything.
>>>>>>>>>>
>>>>>>>>>> I'd got what you posted working with real parts back in 1979 - I'd already done it, so why would I need to do it again?
>>>>>>>>>>
>>>>>>>>>>> So naturally he finds reasons why nothing will work.
>>>>>>>>>>
>>>>>>>>>> I didn't say it wouldn't work - I just pointed out that the transformer model wasn't all that realistic, and neither was the Schmitt trigger.
>>>>>>>>>>
>>>>>>>>>> You could have done quite a bit better, and telling us what you had in mind to use for your transformer would have been a good start.
>>>>>>>>>
>>>>>>>>> Simulationss are useful in that they suggest what should or
>>>>>>>>> could work.
>>>>>>>>>
>>>>>>>>> If you limit it to a specific application, you can introduce
>>>>>>>>> realistic strays and likely operating conditions with increasingly
>>>>>>>>> more accurate models.
>>>>>>>>>
>>>>>>>>> The 'party trick' aspect of this circuit was the miniscule magnetic
>>>>>>>>> component that was possible - though reduction in actual cost shows
>>>>>>>>> diminishing and even reversing returns as you get carried away.
>>>>>>>
>>>>>>> When I cam up with my version of the circuit in 1979 this did strike me as the useful feature. I wasn't tempted to try and get it patented.
>>>>>>>
>>>>>>>>> An integrated magnetic component has been used in some places, though the isolation tended to be compromised.
>>>>>>>
>>>>>>> Integrating anything means realising it within very limited dimensions, and high voltage isolation needs big gaps.
>>>>>>>
>>>>>> Not really. Just needs to be solid. 0.4mm FR4 is approved reinforced. So spiral coils on either side of the PCB could work. In practical size, leakage inductance is high
>>>>>
>>>>> There are down-firing surface-mount leds and photodiodes. One could
>>>>> couple light through a board.
>>>>>
>>>>> Or e-fields, an FR4 capacitor based signal or power coupler.
>>>>>
>>>>>
>>>>>
>>>> I have done both the AM modulated transformer and the E field. Both tend to emit a lot of radiated noise, so you need to keep it to only transitions transmission
>>>>
>>>> Also, they can be subceptible to EMC burst
>>>>
>>>> LED method is clean, but slow
>>> With blind vias one could make a shielded capacitor!
>>>
>>> I should try some stacked stripline couplers on a future test board.
>>> Parts made of copper inside PCBs are free!
>> That would be very interesting to try out, for sure :-)
>
> I've done something similar in a high-volume automotive product where
> a pulsed infra-red diode (for the MOST bus) was producing excessive rf
> emissions. It was not possible to place decoupling capacitors close
> enough to the pins of the driver module because of keep-out rules for the
> selective wave soldering of the module.
> The solution was to build a multi-layer capacitor from alternating power
> and ground planes directly under the device. It worked really well.
You could elaborate that to EMC Y caps over a barrier (needed to return
the CM current). A large PCB inner layer plate has very good HF
properties (and free)

On 01/01/2022 02.30, Anthony William Sloman wrote:
> On Saturday, January 1, 2022 at 4:24:04 AM UTC+11, jla...@highlandsniptechnology.com wrote:
>> On Fri, 31 Dec 2021 11:38:25 -0500, legg <le...@nospam.magma.ca> wrote:
>>
>>> On Thu, 30 Dec 2021 19:05:06 -0800 (PST), Anthony William Sloman
>>> <bill....@ieee.org> wrote:
>>>
>>>> On Friday, December 31, 2021 at 5:21:07 AM UTC+11, John Larkin wrote:
>>>>> On Thu, 30 Dec 2021 09:08:03 -0500, legg <le...@nospam.magma.ca> wrote:
>>>>>
>>>>>> On Thu, 30 Dec 2021 19:04:22 +1100, Sylvia Else <syl...@email.invalid>
>>>>>> wrote:
>>>>>>
>>>>>>> On 30-Dec-21 4:11 pm, jla...@highlandsniptechnology.com wrote:
>>>>>>>> Version 4
>>>>>>>
>>>>>>> <snip>
>>>>>>>
>>>>>>> What is the use-case for this that a conventional digital isolator
>>>>>>> wouldn't be suitable for?
>>>>>>
>>>>>> Sometimes used in lower frequency isolated gate drive, when minimal
>>>>>> magnetics cost is the aim.
>>>>>
>>>>> It's faster than most isolators, and is DC-coupled, after a power-up
>>>>> priming shot.
>>>>
>>>> Not a claim that's worth making for a purely theoretical transformer driving an LT Spice generic Schmitt trigger.
>>>>
>>>> No parallel capacitance across either inductor, and no current induced in the transformer core - it's a little too theoretical too swank about.
>>>>
>>>> It worked fine when I did it in 1979, but I wasn't around to see it go into production (if it did).
>>>
>>> Getting the model to act like the real thing takes time
>>> and effort.
>>>
>>> Getting the real thing to act like the model is probably
>>> delusional.
>>
>> Right, it's best to avoid designing any electronics. It's too hard and too risky.
>
> Anybody else would being intentionally satirical, but since John Larkin doesn't design electronics but rather evolves his circuits by making lots of small changes and seeing what effect they have, which may be tedious but doesn't seem to be difficult or all that expensive (if you can do it by hacking existing board) he may be posting with a straight face.
>
> For the record, designing novel circuits is hard and risky, but it can pay off.
>
In todays world of offers like JLCPCB it costs next to nothing to get an
assembled board done. Why don't you try to build the Bandaxall converter
and tell us about the results?

On Tuesday, January 4, 2022 at 7:22:13 AM UTC+11, Klaus Kragelund wrote:
> On 02/01/2022 13.05, Anthony William Sloman wrote:
> > On Sunday, January 2, 2022 at 8:09:33 PM UTC+11, Klaus Kragelund wrote:
> >> 02.01.22 02:38, Anthony William Sloman wrote:
> >>> On Sunday, January 2, 2022 at 7:45:52 AM UTC+11, jla...@highlandsniptechnology.com wrote:
> >>>> On Sat, 01 Jan 2022 13:45:00 -0500, legg <le...@nospam.magma.ca> wrote:
> >>>>
> >>>>> On Sat, 1 Jan 2022 04:01:57 -0800 (PST), Anthony William Sloman
> >>>>> <bill....@ieee.org> wrote:
> >>>>>
> >>>>>> On Saturday, January 1, 2022 at 12:43:32 PM UTC+11, jla...@highlandsniptechnology.com wrote:
> >>>>>>> On Fri, 31 Dec 2021 20:21:16 -0500, legg <le...@nospam.magma.ca> wrote:
> >>>>>>>> On Fri, 31 Dec 2021 09:23:48 -0800, jla...@highlandsniptechnology.com wrote:
> >>>>>>>>> On Fri, 31 Dec 2021 11:38:25 -0500, legg <le...@nospam.magma.ca> wrote:
> >>>>>>>>>> On Thu, 30 Dec 2021 19:05:06 -0800 (PST), Anthony William Sloman <bill....@ieee.org> wrote:
> >>>>>>>>>>> On Friday, December 31, 2021 at 5:21:07 AM UTC+11, John Larkin wrote:
> >>>>>>>>>>>> On Thu, 30 Dec 2021 09:08:03 -0500, legg <le...@nospam.magma..ca> wrote:
> >>>>>>>>>>>>
> >>>>>>>>>>>>> On Thu, 30 Dec 2021 19:04:22 +1100, Sylvia Else <syl...@email.invalid>
> >>>>>>>>>>>>> wrote:
> >>>>>>>>>>>>>
> >>>>>>>>>>>>>> On 30-Dec-21 4:11 pm, jla...@highlandsniptechnology.com wrote:
> >>>>>>>>>>>>>>> Version 4
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>> <snip>
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>> What is the use-case for this that a conventional digital isolator
> >>>>>>>>>>>>>> wouldn't be suitable for?
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> Sometimes used in lower frequency isolated gate drive, when minimal
> >>>>>>>>>>>>> magnetics cost is the aim.
> >>>>>>>>>>>>
> >>>>>>>>>>>> It's faster than most isolators, and is DC-coupled, after a power-up
> >>>>>>>>>>>> priming shot.
> >>>>>>>>>>>
> >>>>>>>>>>> Not a claim that's worth making for a purely theoretical transformer driving an LT Spice generic Schmitt trigger.
> >>>>>>>>>>>
> >>>>>>>>>>> No parallel capacitance across either inductor, and no current induced in the transformer core - it's a little too theoretical too swank about.
> >>>>>>>>>>>
> >>>>>>>>>>> It worked fine when I did it in 1979, but I wasn't around to see it go into production (if it did).
> >>>>>>>>>>
> >>>>>>>>>> Getting the model to act like the real thing takes time and effort.
> >>>>>>>>>>
> >>>>>>>>>> Getting the real thing to act like the model is probably delusional.
> >>>>>>>>>
> >>>>>>>>> Right, it's best to avoid designing any electronics. It's too hard and
> >>>>>>>>> too risky.
> >>>>>>>>
> >>>>>>>> Hey! The model works! What's HIS problem . . . ?
> >>>>>>>
> >>>>>>> Do you mean Sloman?
> >>>>>>
> >>>>>> Legg was responding to one of your posts, not mine.
> >>>>>>
> >>>>>>> He's the group leader on never actually doing anything.
> >>>>>>
> >>>>>> I'd got what you posted working with real parts back in 1979 - I'd already done it, so why would I need to do it again?
> >>>>>>
> >>>>>>> So naturally he finds reasons why nothing will work.
> >>>>>>
> >>>>>> I didn't say it wouldn't work - I just pointed out that the transformer model wasn't all that realistic, and neither was the Schmitt trigger.
> >>>>>>
> >>>>>> You could have done quite a bit better, and telling us what you had in mind to use for your transformer would have been a good start.
> >>>>>
> >>>>> Simulationss are useful in that they suggest what should or
> >>>>> could work.
> >>>>>
> >>>>> If you limit it to a specific application, you can introduce
> >>>>> realistic strays and likely operating conditions with increasingly
> >>>>> more accurate models.
> >>>>>
> >>>>> The 'party trick' aspect of this circuit was the miniscule magnetic
> >>>>> component that was possible - though reduction in actual cost shows
> >>>>> diminishing and even reversing returns as you get carried away.
> >>>
> >>> When I cam up with my version of the circuit in 1979 this did strike me as the useful feature. I wasn't tempted to try and get it patented.
> >>>
> >>>>> An integrated magnetic component has been used in some places, though the isolation tended to be compromised.
> >>>
> >>> Integrating anything means realising it within very limited dimensions, and high voltage isolation needs big gaps.
> >>>
> >> Not really. Just needs to be solid. 0.4mm FR4 is approved reinforced. So spiral coils on either side of the PCB could work. In practical size, leakage inductance is high
> >
> > Integration is usually taken to be putting stuff together on a silicon substrate (or GaAs or some other kind of semi-conductor). Anything that gets soldered onto FR4 creates an assembled device, not an integrated part.
> >
> That's your definition. If I integrate a coil into a PCB with no added
> components, I would call that.... integrated ;-)
> > Alumina would probably be a better high voltage substrate than FR4-epoxy bonded fibre-glass, but arcs have a nasty way of tracking across insulators.
>
> Not practical for a PCB. Mixing alumina and FR4 makes it very expensive.

You used to be able to get thick film hybrids made on alumina. They might have been described as the rich man's printed circuit, through the conductors were silk-screened onto the alumina, along with the resistors and the solder paste. I've no idea whether anybody still does this, but FR4-expoxy-glass substrates are just one of many available substrates.

--
Bill Sloman, Sydney

On Tuesday, January 4, 2022 at 7:28:48 AM UTC+11, Klaus Kragelund wrote:
> On 01/01/2022 02.30, Anthony William Sloman wrote:
> > On Saturday, January 1, 2022 at 4:24:04 AM UTC+11, jla...@highlandsniptechnology.com wrote:
> >> On Fri, 31 Dec 2021 11:38:25 -0500, legg <le...@nospam.magma.ca> wrote:
> >>
> >>> On Thu, 30 Dec 2021 19:05:06 -0800 (PST), Anthony William Sloman
> >>> <bill....@ieee.org> wrote:
> >>>
> >>>> On Friday, December 31, 2021 at 5:21:07 AM UTC+11, John Larkin wrote:
> >>>>> On Thu, 30 Dec 2021 09:08:03 -0500, legg <le...@nospam.magma.ca> wrote:
> >>>>>
> >>>>>> On Thu, 30 Dec 2021 19:04:22 +1100, Sylvia Else <syl...@email.invalid>
> >>>>>> wrote:
> >>>>>>
> >>>>>>> On 30-Dec-21 4:11 pm, jla...@highlandsniptechnology.com wrote:
> >>>>>>>> Version 4
> >>>>>>>
> >>>>>>> <snip>
> >>>>>>>
> >>>>>>> What is the use-case for this that a conventional digital isolator
> >>>>>>> wouldn't be suitable for?
> >>>>>>
> >>>>>> Sometimes used in lower frequency isolated gate drive, when minimal
> >>>>>> magnetics cost is the aim.
> >>>>>
> >>>>> It's faster than most isolators, and is DC-coupled, after a power-up
> >>>>> priming shot.
> >>>>
> >>>> Not a claim that's worth making for a purely theoretical transformer driving an LT Spice generic Schmitt trigger.
> >>>>
> >>>> No parallel capacitance across either inductor, and no current induced in the transformer core - it's a little too theoretical too swank about.
> >>>>
> >>>> It worked fine when I did it in 1979, but I wasn't around to see it go into production (if it did).
> >>>
> >>> Getting the model to act like the real thing takes time
> >>> and effort.
> >>>
> >>> Getting the real thing to act like the model is probably
> >>> delusional.
> >>
> >> Right, it's best to avoid designing any electronics. It's too hard and too risky.
> >
> > Anybody else would being intentionally satirical, but since John Larkin doesn't design electronics but rather evolves his circuits by making lots of small changes and seeing what effect they have, which may be tedious but doesn't seem to be difficult or all that expensive (if you can do it by hacking existing board) he may be posting with a straight face.
> >
> > For the record, designing novel circuits is hard and risky, but it can pay off.
> >
> In todays world of offers like JLCPCB it costs next to nothing to get an
> assembled board done. Why don't you try to build the Bandaxall converter
> and tell us about the results?

The Baxandall inverter was made very popular by Jim Williams (Linear Technology application notes AN45, AN49, AN51, AN55, AN61, AN65). He didn't call it that, because whoever it was in England who told him about the circuit didn't tell him where it came from. Why would I bother to duplicate his results?

I am tempted to build an example of my low distortion tunable oscillator - I did start putting it into KiCad - but without a prospective customer I can't work up any enthusiasm at all.

--
Bill Sloman, Sydney

On 04/01/2022 03.06, Anthony William Sloman wrote:
> On Tuesday, January 4, 2022 at 7:22:13 AM UTC+11, Klaus Kragelund wrote:
>> On 02/01/2022 13.05, Anthony William Sloman wrote:
>>> On Sunday, January 2, 2022 at 8:09:33 PM UTC+11, Klaus Kragelund wrote:
>>>> 02.01.22 02:38, Anthony William Sloman wrote:
>>>>> On Sunday, January 2, 2022 at 7:45:52 AM UTC+11, jla...@highlandsniptechnology.com wrote:
>>>>>> On Sat, 01 Jan 2022 13:45:00 -0500, legg <le...@nospam.magma.ca> wrote:
>>>>>>
>>>>>>> On Sat, 1 Jan 2022 04:01:57 -0800 (PST), Anthony William Sloman
>>>>>>> <bill....@ieee.org> wrote:
>>>>>>>
>>>>>>>> On Saturday, January 1, 2022 at 12:43:32 PM UTC+11, jla...@highlandsniptechnology.com wrote:
>>>>>>>>> On Fri, 31 Dec 2021 20:21:16 -0500, legg <le...@nospam.magma.ca> wrote:
>>>>>>>>>> On Fri, 31 Dec 2021 09:23:48 -0800, jla...@highlandsniptechnology.com wrote:
>>>>>>>>>>> On Fri, 31 Dec 2021 11:38:25 -0500, legg <le...@nospam.magma.ca> wrote:
>>>>>>>>>>>> On Thu, 30 Dec 2021 19:05:06 -0800 (PST), Anthony William Sloman <bill....@ieee.org> wrote:
>>>>>>>>>>>>> On Friday, December 31, 2021 at 5:21:07 AM UTC+11, John Larkin wrote:
>>>>>>>>>>>>>> On Thu, 30 Dec 2021 09:08:03 -0500, legg <le...@nospam.magma.ca> wrote:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> On Thu, 30 Dec 2021 19:04:22 +1100, Sylvia Else <syl...@email.invalid>
>>>>>>>>>>>>>>> wrote:
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> On 30-Dec-21 4:11 pm, jla...@highlandsniptechnology.com wrote:
>>>>>>>>>>>>>>>>> Version 4
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> <snip>
>>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>> What is the use-case for this that a conventional digital isolator
>>>>>>>>>>>>>>>> wouldn't be suitable for?
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Sometimes used in lower frequency isolated gate drive, when minimal
>>>>>>>>>>>>>>> magnetics cost is the aim.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> It's faster than most isolators, and is DC-coupled, after a power-up
>>>>>>>>>>>>>> priming shot.
>>>>>>>>>>>>>
>>>>>>>>>>>>> Not a claim that's worth making for a purely theoretical transformer driving an LT Spice generic Schmitt trigger.
>>>>>>>>>>>>>
>>>>>>>>>>>>> No parallel capacitance across either inductor, and no current induced in the transformer core - it's a little too theoretical too swank about.
>>>>>>>>>>>>>
>>>>>>>>>>>>> It worked fine when I did it in 1979, but I wasn't around to see it go into production (if it did).
>>>>>>>>>>>>
>>>>>>>>>>>> Getting the model to act like the real thing takes time and effort.
>>>>>>>>>>>>
>>>>>>>>>>>> Getting the real thing to act like the model is probably delusional.
>>>>>>>>>>>
>>>>>>>>>>> Right, it's best to avoid designing any electronics. It's too hard and
>>>>>>>>>>> too risky.
>>>>>>>>>>
>>>>>>>>>> Hey! The model works! What's HIS problem . . . ?
>>>>>>>>>
>>>>>>>>> Do you mean Sloman?
>>>>>>>>
>>>>>>>> Legg was responding to one of your posts, not mine.
>>>>>>>>
>>>>>>>>> He's the group leader on never actually doing anything.
>>>>>>>>
>>>>>>>> I'd got what you posted working with real parts back in 1979 - I'd already done it, so why would I need to do it again?
>>>>>>>>
>>>>>>>>> So naturally he finds reasons why nothing will work.
>>>>>>>>
>>>>>>>> I didn't say it wouldn't work - I just pointed out that the transformer model wasn't all that realistic, and neither was the Schmitt trigger.
>>>>>>>>
>>>>>>>> You could have done quite a bit better, and telling us what you had in mind to use for your transformer would have been a good start.
>>>>>>>
>>>>>>> Simulationss are useful in that they suggest what should or
>>>>>>> could work.
>>>>>>>
>>>>>>> If you limit it to a specific application, you can introduce
>>>>>>> realistic strays and likely operating conditions with increasingly
>>>>>>> more accurate models.
>>>>>>>
>>>>>>> The 'party trick' aspect of this circuit was the miniscule magnetic
>>>>>>> component that was possible - though reduction in actual cost shows
>>>>>>> diminishing and even reversing returns as you get carried away.
>>>>>
>>>>> When I cam up with my version of the circuit in 1979 this did strike me as the useful feature. I wasn't tempted to try and get it patented.
>>>>>
>>>>>>> An integrated magnetic component has been used in some places, though the isolation tended to be compromised.
>>>>>
>>>>> Integrating anything means realising it within very limited dimensions, and high voltage isolation needs big gaps.
>>>>>
>>>> Not really. Just needs to be solid. 0.4mm FR4 is approved reinforced. So spiral coils on either side of the PCB could work. In practical size, leakage inductance is high
>>>
>>> Integration is usually taken to be putting stuff together on a silicon substrate (or GaAs or some other kind of semi-conductor). Anything that gets soldered onto FR4 creates an assembled device, not an integrated part.
>>>
>> That's your definition. If I integrate a coil into a PCB with no added
>> components, I would call that.... integrated ;-)
>>> Alumina would probably be a better high voltage substrate than FR4-epoxy bonded fibre-glass, but arcs have a nasty way of tracking across insulators.
>>
>> Not practical for a PCB. Mixing alumina and FR4 makes it very expensive.
>
> You used to be able to get thick film hybrids made on alumina. They might have been described as the rich man's printed circuit, through the conductors were silk-screened onto the alumina, along with the resistors and the solder paste. I've no idea whether anybody still does this, but FR4-expoxy-glass substrates are just one of many available substrates.
>
You can get cheap alumina PCBs, but then it's single layer traces, and
that can only be used for very simple designs

On Tuesday, January 4, 2022 at 6:53:42 PM UTC+11, Klaus Kragelund wrote:
> On 04/01/2022 03.06, Anthony William Sloman wrote:
> > On Tuesday, January 4, 2022 at 7:22:13 AM UTC+11, Klaus Kragelund wrote:
> >> On 02/01/2022 13.05, Anthony William Sloman wrote:
> >>> On Sunday, January 2, 2022 at 8:09:33 PM UTC+11, Klaus Kragelund wrote:
> >>>> 02.01.22 02:38, Anthony William Sloman wrote:
> >>>>> On Sunday, January 2, 2022 at 7:45:52 AM UTC+11, jla...@highlandsniptechnology.com wrote:
> >>>>>> On Sat, 01 Jan 2022 13:45:00 -0500, legg <le...@nospam.magma.ca> wrote:
> >>>>>>
> >>>>>>> On Sat, 1 Jan 2022 04:01:57 -0800 (PST), Anthony William Sloman
> >>>>>>> <bill....@ieee.org> wrote:
> >>>>>>>
> >>>>>>>> On Saturday, January 1, 2022 at 12:43:32 PM UTC+11, jla...@highlandsniptechnology.com wrote:
> >>>>>>>>> On Fri, 31 Dec 2021 20:21:16 -0500, legg <le...@nospam.magma.ca> wrote:
> >>>>>>>>>> On Fri, 31 Dec 2021 09:23:48 -0800, jla...@highlandsniptechnology.com wrote:
> >>>>>>>>>>> On Fri, 31 Dec 2021 11:38:25 -0500, legg <le...@nospam.magma.ca> wrote:
> >>>>>>>>>>>> On Thu, 30 Dec 2021 19:05:06 -0800 (PST), Anthony William Sloman <bill....@ieee.org> wrote:
> >>>>>>>>>>>>> On Friday, December 31, 2021 at 5:21:07 AM UTC+11, John Larkin wrote:
> >>>>>>>>>>>>>> On Thu, 30 Dec 2021 09:08:03 -0500, legg <le...@nospam.magma.ca> wrote:
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>>> On Thu, 30 Dec 2021 19:04:22 +1100, Sylvia Else <syl...@email.invalid>
> >>>>>>>>>>>>>>> wrote:
> >>>>>>>>>>>>>>>
> >>>>>>>>>>>>>>>> On 30-Dec-21 4:11 pm, jla...@highlandsniptechnology.com wrote:
> >>>>>>>>>>>>>>>>> Version 4
> >>>>>>>>>>>>>>>>
> >>>>>>>>>>>>>>>> <snip>
> >>>>>>>>>>>>>>>>
> >>>>>>>>>>>>>>>> What is the use-case for this that a conventional digital isolator
> >>>>>>>>>>>>>>>> wouldn't be suitable for?
> >>>>>>>>>>>>>>>
> >>>>>>>>>>>>>>> Sometimes used in lower frequency isolated gate drive, when minimal
> >>>>>>>>>>>>>>> magnetics cost is the aim.
> >>>>>>>>>>>>>>
> >>>>>>>>>>>>>> It's faster than most isolators, and is DC-coupled, after a power-up
> >>>>>>>>>>>>>> priming shot.
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> Not a claim that's worth making for a purely theoretical transformer driving an LT Spice generic Schmitt trigger.
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> No parallel capacitance across either inductor, and no current induced in the transformer core - it's a little too theoretical too swank about.
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> It worked fine when I did it in 1979, but I wasn't around to see it go into production (if it did).
> >>>>>>>>>>>>
> >>>>>>>>>>>> Getting the model to act like the real thing takes time and effort.
> >>>>>>>>>>>>
> >>>>>>>>>>>> Getting the real thing to act like the model is probably delusional.
> >>>>>>>>>>>
> >>>>>>>>>>> Right, it's best to avoid designing any electronics. It's too hard and
> >>>>>>>>>>> too risky.
> >>>>>>>>>>
> >>>>>>>>>> Hey! The model works! What's HIS problem . . . ?
> >>>>>>>>>
> >>>>>>>>> Do you mean Sloman?
> >>>>>>>>
> >>>>>>>> Legg was responding to one of your posts, not mine.
> >>>>>>>>
> >>>>>>>>> He's the group leader on never actually doing anything.
> >>>>>>>>
> >>>>>>>> I'd got what you posted working with real parts back in 1979 - I'd already done it, so why would I need to do it again?
> >>>>>>>>
> >>>>>>>>> So naturally he finds reasons why nothing will work.
> >>>>>>>>
> >>>>>>>> I didn't say it wouldn't work - I just pointed out that the transformer model wasn't all that realistic, and neither was the Schmitt trigger.
> >>>>>>>>
> >>>>>>>> You could have done quite a bit better, and telling us what you had in mind to use for your transformer would have been a good start.
> >>>>>>>
> >>>>>>> Simulationss are useful in that they suggest what should or
> >>>>>>> could work.
> >>>>>>>
> >>>>>>> If you limit it to a specific application, you can introduce
> >>>>>>> realistic strays and likely operating conditions with increasingly
> >>>>>>> more accurate models.
> >>>>>>>
> >>>>>>> The 'party trick' aspect of this circuit was the miniscule magnetic
> >>>>>>> component that was possible - though reduction in actual cost shows
> >>>>>>> diminishing and even reversing returns as you get carried away.
> >>>>>
> >>>>> When I cam up with my version of the circuit in 1979 this did strike me as the useful feature. I wasn't tempted to try and get it patented.
> >>>>>
> >>>>>>> An integrated magnetic component has been used in some places, though the isolation tended to be compromised.
> >>>>>
> >>>>> Integrating anything means realising it within very limited dimensions, and high voltage isolation needs big gaps.
> >>>>>
> >>>> Not really. Just needs to be solid. 0.4mm FR4 is approved reinforced.. So spiral coils on either side of the PCB could work. In practical size, leakage inductance is high
> >>>
> >>> Integration is usually taken to be putting stuff together on a silicon substrate (or GaAs or some other kind of semi-conductor). Anything that gets soldered onto FR4 creates an assembled device, not an integrated part.
> >>>
> >> That's your definition. If I integrate a coil into a PCB with no added
> >> components, I would call that.... integrated ;-)
> >>> Alumina would probably be a better high voltage substrate than FR4-epoxy bonded fibre-glass, but arcs have a nasty way of tracking across insulators.
> >>
> >> Not practical for a PCB. Mixing alumina and FR4 makes it very expensive.
> >
> > You used to be able to get thick film hybrids made on alumina. They might have been described as the rich man's printed circuit, through the conductors were silk-screened onto the alumina, along with the resistors and the solder paste. I've no idea whether anybody still does this, but FR4-expoxy-glass substrates are just one of many available substrates.
> >
> You can get cheap alumina PCBs, but then it's single layer traces, and that can only be used for very simple designs.

"Cheap" does exclude some schemes for doing better. Putting a via through an alumina substrate isn't cheap, but it can be done.

--
Bill Sloman, Sydney

On Saturday, January 1, 2022 at 12:45:52 PM UTC-8, jla...@highlandsniptechnology.com wrote:
> On Sat, 01 Jan 2022 13:45:00 -0500, legg <le...@nospam.magma.ca> wrote:
>
> >On Sat, 1 Jan 2022 04:01:57 -0800 (PST), Anthony William Sloman
> ><bill....@ieee.org> wrote:
> >
> >>On Saturday, January 1, 2022 at 12:43:32 PM UTC+11, jla...@highlandsniptechnology.com wrote:
> >>> On Fri, 31 Dec 2021 20:21:16 -0500, legg <le...@nospam.magma.ca> wrote:
> >>> >On Fri, 31 Dec 2021 09:23:48 -0800, jla...@highlandsniptechnology.com wrote:
> >>> >>On Fri, 31 Dec 2021 11:38:25 -0500, legg <le...@nospam.magma.ca> wrote:
> >>> >>>On Thu, 30 Dec 2021 19:05:06 -0800 (PST), Anthony William Sloman <bill....@ieee.org> wrote:
> >>> >>>>On Friday, December 31, 2021 at 5:21:07 AM UTC+11, John Larkin wrote:
> >>> >>>>> On Thu, 30 Dec 2021 09:08:03 -0500, legg <le...@nospam.magma.ca> wrote:
> >>> >>>>>
> >>> >>>>> >On Thu, 30 Dec 2021 19:04:22 +1100, Sylvia Else <syl...@email.invalid>
> >>> >>>>> >wrote:
> >>> >>>>> >
> >>> >>>>> >>On 30-Dec-21 4:11 pm, jla...@highlandsniptechnology.com wrote:
> >>> >>>>> >>> Version 4
> >>> >>>>> >>
> >>> >>>>> >><snip>
> >>> >>>>> >>
> >>> >>>>> >>What is the use-case for this that a conventional digital isolator
> >>> >>>>> >>wouldn't be suitable for?
> >>> >>>>> >
> >>> >>>>> >Sometimes used in lower frequency isolated gate drive, when minimal
> >>> >>>>> >magnetics cost is the aim.
> >>> >>>>>
> >>> >>>>> It's faster than most isolators, and is DC-coupled, after a power-up
> >>> >>>>> priming shot.
> >>> >>>>
> >>> >>>>Not a claim that's worth making for a purely theoretical transformer driving an LT Spice generic Schmitt trigger.
> >>> >>>>
> >>> >>>>No parallel capacitance across either inductor, and no current induced in the transformer core - it's a little too theoretical too swank about.
> >>> >>>>
> >>> >>>>It worked fine when I did it in 1979, but I wasn't around to see it go into production (if it did).
> >>> >>>
> >>> >>>Getting the model to act like the real thing takes time and effort.
> >>> >>>
> >>> >>>Getting the real thing to act like the model is probably delusional.
> >>> >>
> >>> >>Right, it's best to avoid designing any electronics. It's too hard and
> >>> >>too risky.
> >>> >
> >>> >Hey! The model works! What's HIS problem . . . ?
> >>>
> >>> Do you mean Sloman?
> >>
> >>Legg was responding to one of your posts, not mine.
> >>
> >>> He's the group leader on never actually doing anything.
> >>
> >>I'd got what you posted working with real parts back in 1979 - I'd already done it, so why would I need to do it again?
> >>
> >>> So naturally he finds reasons why nothing will work.
> >>
> >>I didn't say it wouldn't work - I just pointed out that the transformer model wasn't all that realistic, and neither was the Schmitt trigger.
> >>
> >>You could have done quite a bit better, and telling us what you had in mind to use for your transformer would have been a good start.
> >
> >Simulationss are useful in that they suggest what should or
> >could work.
> >
> >If you limit it to a specific application, you can introduce
> >realistic strays and likely operating conditions with increasingly
> >more accurate models.
> >
> >The 'party trick' aspect of this circuit was the miniscule magnetic
> >component that was possible - though reduction in actual cost shows
> >diminishing and even reversing returns as you get carried away.
> >An integrated magnetic component has been used in some places,
> >though the isolation tended to be compromised.
> >
> >Semiconductor 'pulse stretchers' go back to the mid 70's. Physical
> >iteration may still be the fastest way to implimentation for a
> >practical app, though a pencil and paper can cut this work down.
> >The simulation just eats man-hours.
> >
> >RL
> Spice is great. It lets a person play with ideas quickly, explore
> hunches, get quantitative with the things that look promising.
> Sometimes I design a circuit and understand it later, if ever.
>
> https://www.youtube.com/watch?v=x6TrbD7-IwU
>
> "Intuition is the most important part of engineering."
>
> "The function of a simulator is to train your instincts."

I happened to be reading a bio on Richard Hamming today:

"The purpose of computing is insight, not numbers."

On Tue, 4 Jan 2022 19:23:26 -0800 (PST), Simon S Aysdie
<gwhite@ti.com> wrote:

>On Saturday, January 1, 2022 at 12:45:52 PM UTC-8, jla...@highlandsniptechnology.com wrote:
>> On Sat, 01 Jan 2022 13:45:00 -0500, legg <le...@nospam.magma.ca> wrote:
>>
>> >On Sat, 1 Jan 2022 04:01:57 -0800 (PST), Anthony William Sloman
>> ><bill....@ieee.org> wrote:
>> >
>> >>On Saturday, January 1, 2022 at 12:43:32 PM UTC+11, jla...@highlandsniptechnology.com wrote:
>> >>> On Fri, 31 Dec 2021 20:21:16 -0500, legg <le...@nospam.magma.ca> wrote:
>> >>> >On Fri, 31 Dec 2021 09:23:48 -0800, jla...@highlandsniptechnology.com wrote:
>> >>> >>On Fri, 31 Dec 2021 11:38:25 -0500, legg <le...@nospam.magma.ca> wrote:
>> >>> >>>On Thu, 30 Dec 2021 19:05:06 -0800 (PST), Anthony William Sloman <bill....@ieee.org> wrote:
>> >>> >>>>On Friday, December 31, 2021 at 5:21:07 AM UTC+11, John Larkin wrote:
>> >>> >>>>> On Thu, 30 Dec 2021 09:08:03 -0500, legg <le...@nospam.magma.ca> wrote:
>> >>> >>>>>
>> >>> >>>>> >On Thu, 30 Dec 2021 19:04:22 +1100, Sylvia Else <syl...@email.invalid>
>> >>> >>>>> >wrote:
>> >>> >>>>> >
>> >>> >>>>> >>On 30-Dec-21 4:11 pm, jla...@highlandsniptechnology.com wrote:
>> >>> >>>>> >>> Version 4
>> >>> >>>>> >>
>> >>> >>>>> >><snip>
>> >>> >>>>> >>
>> >>> >>>>> >>What is the use-case for this that a conventional digital isolator
>> >>> >>>>> >>wouldn't be suitable for?
>> >>> >>>>> >
>> >>> >>>>> >Sometimes used in lower frequency isolated gate drive, when minimal
>> >>> >>>>> >magnetics cost is the aim.
>> >>> >>>>>
>> >>> >>>>> It's faster than most isolators, and is DC-coupled, after a power-up
>> >>> >>>>> priming shot.
>> >>> >>>>
>> >>> >>>>Not a claim that's worth making for a purely theoretical transformer driving an LT Spice generic Schmitt trigger.
>> >>> >>>>
>> >>> >>>>No parallel capacitance across either inductor, and no current induced in the transformer core - it's a little too theoretical too swank about.
>> >>> >>>>
>> >>> >>>>It worked fine when I did it in 1979, but I wasn't around to see it go into production (if it did).
>> >>> >>>
>> >>> >>>Getting the model to act like the real thing takes time and effort.
>> >>> >>>
>> >>> >>>Getting the real thing to act like the model is probably delusional.
>> >>> >>
>> >>> >>Right, it's best to avoid designing any electronics. It's too hard and
>> >>> >>too risky.
>> >>> >
>> >>> >Hey! The model works! What's HIS problem . . . ?
>> >>>
>> >>> Do you mean Sloman?
>> >>
>> >>Legg was responding to one of your posts, not mine.
>> >>
>> >>> He's the group leader on never actually doing anything.
>> >>
>> >>I'd got what you posted working with real parts back in 1979 - I'd already done it, so why would I need to do it again?
>> >>
>> >>> So naturally he finds reasons why nothing will work.
>> >>
>> >>I didn't say it wouldn't work - I just pointed out that the transformer model wasn't all that realistic, and neither was the Schmitt trigger.
>> >>
>> >>You could have done quite a bit better, and telling us what you had in mind to use for your transformer would have been a good start.
>> >
>> >Simulationss are useful in that they suggest what should or
>> >could work.
>> >
>> >If you limit it to a specific application, you can introduce
>> >realistic strays and likely operating conditions with increasingly
>> >more accurate models.
>> >
>> >The 'party trick' aspect of this circuit was the miniscule magnetic
>> >component that was possible - though reduction in actual cost shows
>> >diminishing and even reversing returns as you get carried away.
>> >An integrated magnetic component has been used in some places,
>> >though the isolation tended to be compromised.
>> >
>> >Semiconductor 'pulse stretchers' go back to the mid 70's. Physical
>> >iteration may still be the fastest way to implimentation for a
>> >practical app, though a pencil and paper can cut this work down.
>> >The simulation just eats man-hours.
>> >
>> >RL
>> Spice is great. It lets a person play with ideas quickly, explore
>> hunches, get quantitative with the things that look promising.
>> Sometimes I design a circuit and understand it later, if ever.
>>
>> https://www.youtube.com/watch?v=x6TrbD7-IwU
>>
>> "Intuition is the most important part of engineering."
>>
>> "The function of a simulator is to train your instincts."
>
>I happened to be reading a bio on Richard Hamming today:
>
>"The purpose of computing is insight, not numbers."

Well, no.

--

I yam what I yam - Popeye