• switchmode gyrator

    From john larkin@21:1/5 to All on Sat Nov 9 06:08:40 2024
    Inductors are awful. Their energy storage is worse than electrolytic
    caps by about a factor of 1000.

    https://electronics.stackexchange.com/questions/326177/energy-density-comparison-between-inductors-and-capacitors

    One could in theory make a switchmode gyrator that would make a
    capacitor look like a programmable-value inductor.

    I have an application for that, but it would take too much engineering
    and runtime complexity to make it worth doing. I guess I'll just have
    to buy a bunch of giant, heavy custom toroids.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From legg@21:1/5 to john larkin on Tue Nov 12 07:49:13 2024
    On Sat, 09 Nov 2024 06:08:40 -0800, john larkin <JL@gct.com> wrote:



    Inductors are awful. Their energy storage is worse than electrolytic
    caps by about a factor of 1000.

    https://electronics.stackexchange.com/questions/326177/energy-density-comparison-between-inductors-and-capacitors

    One could in theory make a switchmode gyrator that would make a
    capacitor look like a programmable-value inductor.

    I have an application for that, but it would take too much engineering
    and runtime complexity to make it worth doing. I guess I'll just have
    to buy a bunch of giant, heavy custom toroids.

    I'm sure that there are other reasons why an inductor
    will be used besides the lack of time/energy/resources
    to 'design them out'.

    Energy storage is just one means to an end.

    RL

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jeroen Belleman@21:1/5 to john larkin on Tue Nov 12 19:44:39 2024
    On 11/12/24 16:49, john larkin wrote:
    On Tue, 12 Nov 2024 07:49:13 -0500, legg <legg@nospam.magma.ca> wrote:

    On Sat, 09 Nov 2024 06:08:40 -0800, john larkin <JL@gct.com> wrote:



    Inductors are awful. Their energy storage is worse than electrolytic
    caps by about a factor of 1000.

    https://electronics.stackexchange.com/questions/326177/energy-density-comparison-between-inductors-and-capacitors

    One could in theory make a switchmode gyrator that would make a
    capacitor look like a programmable-value inductor.

    I have an application for that, but it would take too much engineering
    and runtime complexity to make it worth doing. I guess I'll just have
    to buy a bunch of giant, heavy custom toroids.

    I'm sure that there are other reasons why an inductor
    will be used besides the lack of time/energy/resources
    to 'design them out'.

    Energy storage is just one means to an end.

    RL

    Sure. We want to design some dummy loads that will simulate relays, solenoids, stepper motors, torque motors, with programmable R and L.
    Seemed to me that using caps to make fake inductors would be a good
    way to do that.

    It's at least an interesting idea to play with. Maybe we can
    switchmode simulate R+L all at once. We would have to store energy and dissipate power to do that.

    Relays and motors do not behave like simple inductors. For example,
    while a relay armature is moving, the back EMF is high enough to
    make the current _drop_ briefly. Modelling that requires more than
    a simple gyrator.

    Jeroen Belleman

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Phil Hobbs@21:1/5 to Jeroen Belleman on Tue Nov 12 19:48:38 2024
    Jeroen Belleman <jeroen@nospam.please> wrote:
    On 11/12/24 16:49, john larkin wrote:
    On Tue, 12 Nov 2024 07:49:13 -0500, legg <legg@nospam.magma.ca> wrote:

    On Sat, 09 Nov 2024 06:08:40 -0800, john larkin <JL@gct.com> wrote:



    Inductors are awful. Their energy storage is worse than electrolytic
    caps by about a factor of 1000.

    https://electronics.stackexchange.com/questions/326177/energy-density-comparison-between-inductors-and-capacitors

    One could in theory make a switchmode gyrator that would make a
    capacitor look like a programmable-value inductor.

    I have an application for that, but it would take too much engineering >>>> and runtime complexity to make it worth doing. I guess I'll just have
    to buy a bunch of giant, heavy custom toroids.

    I'm sure that there are other reasons why an inductor
    will be used besides the lack of time/energy/resources
    to 'design them out'.

    Energy storage is just one means to an end.

    RL

    Sure. We want to design some dummy loads that will simulate relays,
    solenoids, stepper motors, torque motors, with programmable R and L.
    Seemed to me that using caps to make fake inductors would be a good
    way to do that.

    It's at least an interesting idea to play with. Maybe we can
    switchmode simulate R+L all at once. We would have to store energy and
    dissipate power to do that.

    Relays and motors do not behave like simple inductors. For example,
    while a relay armature is moving, the back EMF is high enough to
    make the current _drop_ briefly. Modelling that requires more than
    a simple gyrator.

    Jeroen Belleman



    PM DC motors look capacitive over a broad frequency range.

    Cheers

    Phil Hobbs

    --
    Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to jeroen@nospam.please on Tue Nov 12 14:05:36 2024
    On Tue, 12 Nov 2024 19:44:39 +0100, Jeroen Belleman
    <jeroen@nospam.please> wrote:

    On 11/12/24 16:49, john larkin wrote:
    On Tue, 12 Nov 2024 07:49:13 -0500, legg <legg@nospam.magma.ca> wrote:

    On Sat, 09 Nov 2024 06:08:40 -0800, john larkin <JL@gct.com> wrote:



    Inductors are awful. Their energy storage is worse than electrolytic
    caps by about a factor of 1000.

    https://electronics.stackexchange.com/questions/326177/energy-density-comparison-between-inductors-and-capacitors

    One could in theory make a switchmode gyrator that would make a
    capacitor look like a programmable-value inductor.

    I have an application for that, but it would take too much engineering >>>> and runtime complexity to make it worth doing. I guess I'll just have
    to buy a bunch of giant, heavy custom toroids.

    I'm sure that there are other reasons why an inductor
    will be used besides the lack of time/energy/resources
    to 'design them out'.

    Energy storage is just one means to an end.

    RL

    Sure. We want to design some dummy loads that will simulate relays,
    solenoids, stepper motors, torque motors, with programmable R and L.
    Seemed to me that using caps to make fake inductors would be a good
    way to do that.

    It's at least an interesting idea to play with. Maybe we can
    switchmode simulate R+L all at once. We would have to store energy and
    dissipate power to do that.

    Relays and motors do not behave like simple inductors. For example,
    while a relay armature is moving, the back EMF is high enough to
    make the current _drop_ briefly. Modelling that requires more than
    a simple gyrator.

    Jeroen Belleman

    My customer is building giant rackmount boxes full of heavy inductors
    as part of his dummy loads. We want to replace them.

    Given a generalized switching impedance simulator, I guess one could
    model a DC motor.

    I am considering a powered impedance simulator, not the theoretical
    gyrator. Just sort of a gyrator.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Liz Tuddenham@21:1/5 to john larkin on Wed Nov 13 09:32:56 2024
    john larkin <jl@glen--canyon.com> wrote:

    On Tue, 12 Nov 2024 19:44:39 +0100, Jeroen Belleman
    <jeroen@nospam.please> wrote:

    On 11/12/24 16:49, john larkin wrote:
    On Tue, 12 Nov 2024 07:49:13 -0500, legg <legg@nospam.magma.ca> wrote:

    On Sat, 09 Nov 2024 06:08:40 -0800, john larkin <JL@gct.com> wrote:



    Inductors are awful. Their energy storage is worse than electrolytic >>>> caps by about a factor of 1000.

    https://electronics.stackexchange.com/questions/326177/energy-density- >>>>comparison-between-inductors-and-capacitors

    One could in theory make a switchmode gyrator that would make a
    capacitor look like a programmable-value inductor.

    I have an application for that, but it would take too much engineering >>>> and runtime complexity to make it worth doing. I guess I'll just have >>>> to buy a bunch of giant, heavy custom toroids.

    I'm sure that there are other reasons why an inductor
    will be used besides the lack of time/energy/resources
    to 'design them out'.

    Energy storage is just one means to an end.

    RL

    Sure. We want to design some dummy loads that will simulate relays,
    solenoids, stepper motors, torque motors, with programmable R and L.
    Seemed to me that using caps to make fake inductors would be a good
    way to do that.

    It's at least an interesting idea to play with. Maybe we can
    switchmode simulate R+L all at once. We would have to store energy and
    dissipate power to do that.

    Relays and motors do not behave like simple inductors. For example,
    while a relay armature is moving, the back EMF is high enough to
    make the current _drop_ briefly. Modelling that requires more than
    a simple gyrator.

    Jeroen Belleman

    My customer is building giant rackmount boxes full of heavy inductors
    as part of his dummy loads. We want to replace them.

    If space, weight and stray magnetic fields aren't a problem, big
    inductors can sometimes turn out to be remarkably cheap and efficient
    compared with more complex solutions.


    --
    ~ Liz Tuddenham ~
    (Remove the ".invalid"s and add ".co.uk" to reply)
    www.poppyrecords.co.uk

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From legg@21:1/5 to john larkin on Wed Nov 13 08:11:54 2024
    On Tue, 12 Nov 2024 07:49:55 -0800, john larkin <JL@gct.com> wrote:

    On Tue, 12 Nov 2024 07:49:13 -0500, legg <legg@nospam.magma.ca> wrote:

    On Sat, 09 Nov 2024 06:08:40 -0800, john larkin <JL@gct.com> wrote:



    Inductors are awful. Their energy storage is worse than electrolytic
    caps by about a factor of 1000.
    https://electronics.stackexchange.com/questions/326177/energy-density-comparison-between-inductors-and-capacitors

    One could in theory make a switchmode gyrator that would make a
    capacitor look like a programmable-value inductor.

    I have an application for that, but it would take too much engineering >>>and runtime complexity to make it worth doing. I guess I'll just have
    to buy a bunch of giant, heavy custom toroids.

    I'm sure that there are other reasons why an inductor
    will be used besides the lack of time/energy/resources
    to 'design them out'.

    Energy storage is just one means to an end.

    RL

    Sure. We want to design some dummy loads that will simulate relays, >solenoids, stepper motors, torque motors, with programmable R and L.
    Seemed to me that using caps to make fake inductors would be a good
    way to do that.

    It's at least an interesting idea to play with. Maybe we can
    switchmode simulate R+L all at once. We would have to store energy and >dissipate power to do that.





    Loads - the simpler the better unless there's a return on
    the investment.

    I guess I'll just have to buy a bunch of giant, heavy custom toroids.

    One nice rhing about inductors is that they tend not to
    break.

    Unless it's meant to fly or be hand-carried, weight doesn't
    sell. Used to be a factor in shipping costs.

    RL

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From legg@21:1/5 to All on Wed Nov 13 08:15:37 2024
    On Tue, 12 Nov 2024 14:05:36 -0800, john larkin <jl@glen--canyon.com>
    wrote:

    On Tue, 12 Nov 2024 19:44:39 +0100, Jeroen Belleman
    <jeroen@nospam.please> wrote:

    On 11/12/24 16:49, john larkin wrote:
    On Tue, 12 Nov 2024 07:49:13 -0500, legg <legg@nospam.magma.ca> wrote:

    On Sat, 09 Nov 2024 06:08:40 -0800, john larkin <JL@gct.com> wrote:



    Inductors are awful. Their energy storage is worse than electrolytic >>>>> caps by about a factor of 1000.

    https://electronics.stackexchange.com/questions/326177/energy-density-comparison-between-inductors-and-capacitors

    One could in theory make a switchmode gyrator that would make a
    capacitor look like a programmable-value inductor.

    I have an application for that, but it would take too much engineering >>>>> and runtime complexity to make it worth doing. I guess I'll just have >>>>> to buy a bunch of giant, heavy custom toroids.

    I'm sure that there are other reasons why an inductor
    will be used besides the lack of time/energy/resources
    to 'design them out'.

    Energy storage is just one means to an end.

    RL

    Sure. We want to design some dummy loads that will simulate relays,
    solenoids, stepper motors, torque motors, with programmable R and L.
    Seemed to me that using caps to make fake inductors would be a good
    way to do that.

    It's at least an interesting idea to play with. Maybe we can
    switchmode simulate R+L all at once. We would have to store energy and
    dissipate power to do that.

    Relays and motors do not behave like simple inductors. For example,
    while a relay armature is moving, the back EMF is high enough to
    make the current _drop_ briefly. Modelling that requires more than
    a simple gyrator.

    Jeroen Belleman

    My customer is building giant rackmount boxes full of heavy inductors
    as part of his dummy loads. We want to replace them.

    Given a generalized switching impedance simulator, I guess one could
    model a DC motor.

    I am considering a powered impedance simulator, not the theoretical
    gyrator. Just sort of a gyrator.

    Investing in heavy duty castors for the racks would get more
    bang for the buck.

    RL

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From legg@21:1/5 to All on Wed Nov 13 08:26:58 2024
    On Tue, 12 Nov 2024 14:05:36 -0800, john larkin <jl@glen--canyon.com>
    wrote:

    On Tue, 12 Nov 2024 19:44:39 +0100, Jeroen Belleman
    <jeroen@nospam.please> wrote:

    On 11/12/24 16:49, john larkin wrote:
    On Tue, 12 Nov 2024 07:49:13 -0500, legg <legg@nospam.magma.ca> wrote:

    On Sat, 09 Nov 2024 06:08:40 -0800, john larkin <JL@gct.com> wrote:



    Inductors are awful. Their energy storage is worse than electrolytic >>>>> caps by about a factor of 1000.

    https://electronics.stackexchange.com/questions/326177/energy-density-comparison-between-inductors-and-capacitors

    One could in theory make a switchmode gyrator that would make a
    capacitor look like a programmable-value inductor.

    I have an application for that, but it would take too much engineering >>>>> and runtime complexity to make it worth doing. I guess I'll just have >>>>> to buy a bunch of giant, heavy custom toroids.

    I'm sure that there are other reasons why an inductor
    will be used besides the lack of time/energy/resources
    to 'design them out'.

    Energy storage is just one means to an end.

    RL

    Sure. We want to design some dummy loads that will simulate relays,
    solenoids, stepper motors, torque motors, with programmable R and L.
    Seemed to me that using caps to make fake inductors would be a good
    way to do that.

    It's at least an interesting idea to play with. Maybe we can
    switchmode simulate R+L all at once. We would have to store energy and
    dissipate power to do that.

    Relays and motors do not behave like simple inductors. For example,
    while a relay armature is moving, the back EMF is high enough to
    make the current _drop_ briefly. Modelling that requires more than
    a simple gyrator.

    Jeroen Belleman

    My customer is building giant rackmount boxes full of heavy inductors
    as part of his dummy loads. We want to replace them.

    Given a generalized switching impedance simulator, I guess one could
    model a DC motor.

    I am considering a powered impedance simulator, not the theoretical
    gyrator. Just sort of a gyrator.

    Quote your customer and see if they're as enthused.

    Remind him that he has 'free' loads just crying out
    for burn-in.

    RL

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to Liz Tuddenham on Wed Nov 13 07:41:44 2024
    On Wed, 13 Nov 2024 09:32:56 +0000, liz@poppyrecords.invalid.invalid
    (Liz Tuddenham) wrote:

    john larkin <jl@glen--canyon.com> wrote:

    On Tue, 12 Nov 2024 19:44:39 +0100, Jeroen Belleman
    <jeroen@nospam.please> wrote:

    On 11/12/24 16:49, john larkin wrote:
    On Tue, 12 Nov 2024 07:49:13 -0500, legg <legg@nospam.magma.ca> wrote:

    On Sat, 09 Nov 2024 06:08:40 -0800, john larkin <JL@gct.com> wrote:



    Inductors are awful. Their energy storage is worse than electrolytic
    caps by about a factor of 1000.


    https://electronics.stackexchange.com/questions/326177/energy-density- >> >>>>comparison-between-inductors-and-capacitors

    One could in theory make a switchmode gyrator that would make a
    capacitor look like a programmable-value inductor.

    I have an application for that, but it would take too much engineering >> >>>> and runtime complexity to make it worth doing. I guess I'll just have >> >>>> to buy a bunch of giant, heavy custom toroids.

    I'm sure that there are other reasons why an inductor
    will be used besides the lack of time/energy/resources
    to 'design them out'.

    Energy storage is just one means to an end.

    RL

    Sure. We want to design some dummy loads that will simulate relays,
    solenoids, stepper motors, torque motors, with programmable R and L.
    Seemed to me that using caps to make fake inductors would be a good
    way to do that.

    It's at least an interesting idea to play with. Maybe we can
    switchmode simulate R+L all at once. We would have to store energy and
    dissipate power to do that.

    Relays and motors do not behave like simple inductors. For example,
    while a relay armature is moving, the back EMF is high enough to
    make the current _drop_ briefly. Modelling that requires more than
    a simple gyrator.

    Jeroen Belleman

    My customer is building giant rackmount boxes full of heavy inductors
    as part of his dummy loads. We want to replace them.

    If space, weight and stray magnetic fields aren't a problem, big
    inductors can sometimes turn out to be remarkably cheap and efficient >compared with more complex solutions.

    We have learned that our customers care a great deal about rack space
    and cables. And they used to have techs that built things like load
    boxes, and when those old guys retired they didn't replace them.

    We may make some smaller R+L dummy loads by switching real resistors
    and tapped inductors. That is brain straining, especially specifying
    the tapped inductors.

    I was musing on designing a switchmode programmable synthetic R+L box
    with essentially infinite programmable resolution, and using caps for
    the energy storage instead of real inductors.

    I suppose there can be a generalized impedance simulator.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to legg on Wed Nov 13 07:42:58 2024
    On Wed, 13 Nov 2024 08:15:37 -0500, legg <legg@nospam.magma.ca> wrote:

    On Tue, 12 Nov 2024 14:05:36 -0800, john larkin <jl@glen--canyon.com>
    wrote:

    On Tue, 12 Nov 2024 19:44:39 +0100, Jeroen Belleman
    <jeroen@nospam.please> wrote:

    On 11/12/24 16:49, john larkin wrote:
    On Tue, 12 Nov 2024 07:49:13 -0500, legg <legg@nospam.magma.ca> wrote: >>>>
    On Sat, 09 Nov 2024 06:08:40 -0800, john larkin <JL@gct.com> wrote:



    Inductors are awful. Their energy storage is worse than electrolytic >>>>>> caps by about a factor of 1000.

    https://electronics.stackexchange.com/questions/326177/energy-density-comparison-between-inductors-and-capacitors

    One could in theory make a switchmode gyrator that would make a
    capacitor look like a programmable-value inductor.

    I have an application for that, but it would take too much engineering >>>>>> and runtime complexity to make it worth doing. I guess I'll just have >>>>>> to buy a bunch of giant, heavy custom toroids.

    I'm sure that there are other reasons why an inductor
    will be used besides the lack of time/energy/resources
    to 'design them out'.

    Energy storage is just one means to an end.

    RL

    Sure. We want to design some dummy loads that will simulate relays,
    solenoids, stepper motors, torque motors, with programmable R and L.
    Seemed to me that using caps to make fake inductors would be a good
    way to do that.

    It's at least an interesting idea to play with. Maybe we can
    switchmode simulate R+L all at once. We would have to store energy and >>>> dissipate power to do that.

    Relays and motors do not behave like simple inductors. For example,
    while a relay armature is moving, the back EMF is high enough to
    make the current _drop_ briefly. Modelling that requires more than
    a simple gyrator.

    Jeroen Belleman

    My customer is building giant rackmount boxes full of heavy inductors
    as part of his dummy loads. We want to replace them.

    Given a generalized switching impedance simulator, I guess one could
    model a DC motor.

    I am considering a powered impedance simulator, not the theoretical >>gyrator. Just sort of a gyrator.

    Investing in heavy duty castors for the racks would get more
    bang for the buck.

    RL

    It's hard to get a forklift into some of the test cells.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From legg@21:1/5 to john larkin on Thu Nov 14 08:19:23 2024
    On Wed, 13 Nov 2024 07:41:44 -0800, john larkin <JL@gct.com> wrote:

    On Wed, 13 Nov 2024 09:32:56 +0000, liz@poppyrecords.invalid.invalid
    (Liz Tuddenham) wrote:

    john larkin <jl@glen--canyon.com> wrote:

    On Tue, 12 Nov 2024 19:44:39 +0100, Jeroen Belleman
    <jeroen@nospam.please> wrote:

    On 11/12/24 16:49, john larkin wrote:
    On Tue, 12 Nov 2024 07:49:13 -0500, legg <legg@nospam.magma.ca> wrote: >>> >>
    On Sat, 09 Nov 2024 06:08:40 -0800, john larkin <JL@gct.com> wrote:



    Inductors are awful. Their energy storage is worse than electrolytic >>> >>>> caps by about a factor of 1000.


    https://electronics.stackexchange.com/questions/326177/energy-density- >>> >>>>comparison-between-inductors-and-capacitors

    One could in theory make a switchmode gyrator that would make a
    capacitor look like a programmable-value inductor.

    I have an application for that, but it would take too much engineering >>> >>>> and runtime complexity to make it worth doing. I guess I'll just have >>> >>>> to buy a bunch of giant, heavy custom toroids.

    I'm sure that there are other reasons why an inductor
    will be used besides the lack of time/energy/resources
    to 'design them out'.

    Energy storage is just one means to an end.

    RL

    Sure. We want to design some dummy loads that will simulate relays,
    solenoids, stepper motors, torque motors, with programmable R and L.
    Seemed to me that using caps to make fake inductors would be a good
    way to do that.

    It's at least an interesting idea to play with. Maybe we can
    switchmode simulate R+L all at once. We would have to store energy and >>> >> dissipate power to do that.

    Relays and motors do not behave like simple inductors. For example,
    while a relay armature is moving, the back EMF is high enough to
    make the current _drop_ briefly. Modelling that requires more than
    a simple gyrator.

    Jeroen Belleman

    My customer is building giant rackmount boxes full of heavy inductors
    as part of his dummy loads. We want to replace them.

    If space, weight and stray magnetic fields aren't a problem, big
    inductors can sometimes turn out to be remarkably cheap and efficient >>compared with more complex solutions.

    We have learned that our customers care a great deal about rack space
    and cables. And they used to have techs that built things like load
    boxes, and when those old guys retired they didn't replace them.

    Then be carefull, because you're dealing with the wankers who are
    still hanging around with their fingers . . . .

    We may make some smaller R+L dummy loads by switching real resistors
    and tapped inductors. That is brain straining, especially specifying
    the tapped inductors.

    I was musing on designing a switchmode programmable synthetic R+L box
    with essentially infinite programmable resolution, and using caps for
    the energy storage instead of real inductors.

    I suppose there can be a generalized impedance simulator.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to legg on Thu Nov 14 07:14:49 2024
    On Thu, 14 Nov 2024 08:19:23 -0500, legg <legg@nospam.magma.ca> wrote:

    On Wed, 13 Nov 2024 07:41:44 -0800, john larkin <JL@gct.com> wrote:

    On Wed, 13 Nov 2024 09:32:56 +0000, liz@poppyrecords.invalid.invalid
    (Liz Tuddenham) wrote:

    john larkin <jl@glen--canyon.com> wrote:

    On Tue, 12 Nov 2024 19:44:39 +0100, Jeroen Belleman
    <jeroen@nospam.please> wrote:

    On 11/12/24 16:49, john larkin wrote:
    On Tue, 12 Nov 2024 07:49:13 -0500, legg <legg@nospam.magma.ca> wrote: >>>> >>
    On Sat, 09 Nov 2024 06:08:40 -0800, john larkin <JL@gct.com> wrote: >>>> >>>


    Inductors are awful. Their energy storage is worse than electrolytic >>>> >>>> caps by about a factor of 1000.


    https://electronics.stackexchange.com/questions/326177/energy-density- >>>> >>>>comparison-between-inductors-and-capacitors

    One could in theory make a switchmode gyrator that would make a
    capacitor look like a programmable-value inductor.

    I have an application for that, but it would take too much engineering
    and runtime complexity to make it worth doing. I guess I'll just have >>>> >>>> to buy a bunch of giant, heavy custom toroids.

    I'm sure that there are other reasons why an inductor
    will be used besides the lack of time/energy/resources
    to 'design them out'.

    Energy storage is just one means to an end.

    RL

    Sure. We want to design some dummy loads that will simulate relays, >>>> >> solenoids, stepper motors, torque motors, with programmable R and L. >>>> >> Seemed to me that using caps to make fake inductors would be a good >>>> >> way to do that.

    It's at least an interesting idea to play with. Maybe we can
    switchmode simulate R+L all at once. We would have to store energy and >>>> >> dissipate power to do that.

    Relays and motors do not behave like simple inductors. For example,
    while a relay armature is moving, the back EMF is high enough to
    make the current _drop_ briefly. Modelling that requires more than
    a simple gyrator.

    Jeroen Belleman

    My customer is building giant rackmount boxes full of heavy inductors
    as part of his dummy loads. We want to replace them.

    If space, weight and stray magnetic fields aren't a problem, big >>>inductors can sometimes turn out to be remarkably cheap and efficient >>>compared with more complex solutions.

    We have learned that our customers care a great deal about rack space
    and cables. And they used to have techs that built things like load
    boxes, and when those old guys retired they didn't replace them.

    Then be carefull, because you're dealing with the wankers who are
    still hanging around with their fingers . . . .

    They have billions of dollars to spend, so we're polite to them.

    And we don't want customers who are smart enough to design their own electronics.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Chris Jones@21:1/5 to john larkin on Fri Nov 15 21:28:58 2024
    On 13/11/2024 9:05 am, john larkin wrote:
    On Tue, 12 Nov 2024 19:44:39 +0100, Jeroen Belleman
    <jeroen@nospam.please> wrote:

    On 11/12/24 16:49, john larkin wrote:
    On Tue, 12 Nov 2024 07:49:13 -0500, legg <legg@nospam.magma.ca> wrote:

    On Sat, 09 Nov 2024 06:08:40 -0800, john larkin <JL@gct.com> wrote:



    Inductors are awful. Their energy storage is worse than electrolytic >>>>> caps by about a factor of 1000.

    https://electronics.stackexchange.com/questions/326177/energy-density-comparison-between-inductors-and-capacitors

    One could in theory make a switchmode gyrator that would make a
    capacitor look like a programmable-value inductor.

    I have an application for that, but it would take too much engineering >>>>> and runtime complexity to make it worth doing. I guess I'll just have >>>>> to buy a bunch of giant, heavy custom toroids.

    I'm sure that there are other reasons why an inductor
    will be used besides the lack of time/energy/resources
    to 'design them out'.

    Energy storage is just one means to an end.

    RL

    Sure. We want to design some dummy loads that will simulate relays,
    solenoids, stepper motors, torque motors, with programmable R and L.
    Seemed to me that using caps to make fake inductors would be a good
    way to do that.

    It's at least an interesting idea to play with. Maybe we can
    switchmode simulate R+L all at once. We would have to store energy and
    dissipate power to do that.

    Relays and motors do not behave like simple inductors. For example,
    while a relay armature is moving, the back EMF is high enough to
    make the current _drop_ briefly. Modelling that requires more than
    a simple gyrator.

    Jeroen Belleman

    My customer is building giant rackmount boxes full of heavy inductors
    as part of his dummy loads. We want to replace them.

    Given a generalized switching impedance simulator, I guess one could
    model a DC motor.

    I am considering a powered impedance simulator, not the theoretical
    gyrator. Just sort of a gyrator.


    Many inductive loads can produce kilovolts when switched off suddenly.
    If you build a switched-mode equivalent, unless it contains a large real
    output inductor, your class-D output stage might need supply rails of
    kilovolts to emulate the real inductor accurately. That sounds expensive.

    If the load you are emulating contains a TVS or other clamp as part of
    the load, then it would be easier to emulate, but you wouldn't be able
    to emulate the fault condition where the clamp fails open.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to lugnut808@spam.yahoo.com on Fri Nov 15 07:33:18 2024
    On Fri, 15 Nov 2024 21:28:58 +1100, Chris Jones
    <lugnut808@spam.yahoo.com> wrote:

    On 13/11/2024 9:05 am, john larkin wrote:
    On Tue, 12 Nov 2024 19:44:39 +0100, Jeroen Belleman
    <jeroen@nospam.please> wrote:

    On 11/12/24 16:49, john larkin wrote:
    On Tue, 12 Nov 2024 07:49:13 -0500, legg <legg@nospam.magma.ca> wrote: >>>>
    On Sat, 09 Nov 2024 06:08:40 -0800, john larkin <JL@gct.com> wrote:



    Inductors are awful. Their energy storage is worse than electrolytic >>>>>> caps by about a factor of 1000.

    https://electronics.stackexchange.com/questions/326177/energy-density-comparison-between-inductors-and-capacitors

    One could in theory make a switchmode gyrator that would make a
    capacitor look like a programmable-value inductor.

    I have an application for that, but it would take too much engineering >>>>>> and runtime complexity to make it worth doing. I guess I'll just have >>>>>> to buy a bunch of giant, heavy custom toroids.

    I'm sure that there are other reasons why an inductor
    will be used besides the lack of time/energy/resources
    to 'design them out'.

    Energy storage is just one means to an end.

    RL

    Sure. We want to design some dummy loads that will simulate relays,
    solenoids, stepper motors, torque motors, with programmable R and L.
    Seemed to me that using caps to make fake inductors would be a good
    way to do that.

    It's at least an interesting idea to play with. Maybe we can
    switchmode simulate R+L all at once. We would have to store energy and >>>> dissipate power to do that.

    Relays and motors do not behave like simple inductors. For example,
    while a relay armature is moving, the back EMF is high enough to
    make the current _drop_ briefly. Modelling that requires more than
    a simple gyrator.

    Jeroen Belleman

    My customer is building giant rackmount boxes full of heavy inductors
    as part of his dummy loads. We want to replace them.

    Given a generalized switching impedance simulator, I guess one could
    model a DC motor.

    I am considering a powered impedance simulator, not the theoretical
    gyrator. Just sort of a gyrator.


    Many inductive loads can produce kilovolts when switched off suddenly.
    If you build a switched-mode equivalent, unless it contains a large real >output inductor, your class-D output stage might need supply rails of >kilovolts to emulate the real inductor accurately. That sounds expensive.

    An electronic load would of course have specified voltage, current,
    and power limits.

    But some of the simulated inductance - a few mH maybe - could be real inductors, and they would fly back a bunch. We do need to accept a
    customer PWM drive and sort of behave right.

    I don't think that kilovolt flybacks are common in real areospace
    systems. That could damage wire insulation and interfere with other
    stuff.


    If the load you are emulating contains a TVS or other clamp as part of
    the load, then it would be easier to emulate, but you wouldn't be able
    to emulate the fault condition where the clamp fails open.


    Yes, the customer's drivers have flyback diodes or equivlent, or just
    a continuous low-Z PWM drive. We can't simulate every corner case,
    lightning strikes or major system faults.

    It's just an interesting problem, simulating a pretty high power
    inductor without a hundred pounds of iron. What I'd never thought much
    about is how terrible inductors are at storing energy. Inductor:capacitor:supercap:battery are roughly 1000:1 steps in energy
    density.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Phil Hobbs@21:1/5 to john larkin on Fri Nov 15 17:28:18 2024
    john larkin <JL@gct.com> wrote:
    On Fri, 15 Nov 2024 21:28:58 +1100, Chris Jones
    <lugnut808@spam.yahoo.com> wrote:

    On 13/11/2024 9:05 am, john larkin wrote:
    On Tue, 12 Nov 2024 19:44:39 +0100, Jeroen Belleman
    <jeroen@nospam.please> wrote:

    On 11/12/24 16:49, john larkin wrote:
    On Tue, 12 Nov 2024 07:49:13 -0500, legg <legg@nospam.magma.ca> wrote: >>>>>
    On Sat, 09 Nov 2024 06:08:40 -0800, john larkin <JL@gct.com> wrote: >>>>>>


    Inductors are awful. Their energy storage is worse than electrolytic >>>>>>> caps by about a factor of 1000.

    https://electronics.stackexchange.com/questions/326177/energy-density-comparison-between-inductors-and-capacitors

    One could in theory make a switchmode gyrator that would make a
    capacitor look like a programmable-value inductor.

    I have an application for that, but it would take too much engineering >>>>>>> and runtime complexity to make it worth doing. I guess I'll just have >>>>>>> to buy a bunch of giant, heavy custom toroids.

    I'm sure that there are other reasons why an inductor
    will be used besides the lack of time/energy/resources
    to 'design them out'.

    Energy storage is just one means to an end.

    RL

    Sure. We want to design some dummy loads that will simulate relays,
    solenoids, stepper motors, torque motors, with programmable R and L. >>>>> Seemed to me that using caps to make fake inductors would be a good
    way to do that.

    It's at least an interesting idea to play with. Maybe we can
    switchmode simulate R+L all at once. We would have to store energy and >>>>> dissipate power to do that.

    Relays and motors do not behave like simple inductors. For example,
    while a relay armature is moving, the back EMF is high enough to
    make the current _drop_ briefly. Modelling that requires more than
    a simple gyrator.

    Jeroen Belleman

    My customer is building giant rackmount boxes full of heavy inductors
    as part of his dummy loads. We want to replace them.

    Given a generalized switching impedance simulator, I guess one could
    model a DC motor.

    I am considering a powered impedance simulator, not the theoretical
    gyrator. Just sort of a gyrator.


    Many inductive loads can produce kilovolts when switched off suddenly.
    If you build a switched-mode equivalent, unless it contains a large real
    output inductor, your class-D output stage might need supply rails of
    kilovolts to emulate the real inductor accurately. That sounds expensive.

    An electronic load would of course have specified voltage, current,
    and power limits.

    But some of the simulated inductance - a few mH maybe - could be real inductors, and they would fly back a bunch. We do need to accept a
    customer PWM drive and sort of behave right.

    I don't think that kilovolt flybacks are common in real areospace
    systems. That could damage wire insulation and interfere with other
    stuff.


    If the load you are emulating contains a TVS or other clamp as part of
    the load, then it would be easier to emulate, but you wouldn't be able
    to emulate the fault condition where the clamp fails open.


    Yes, the customer's drivers have flyback diodes or equivlent, or just
    a continuous low-Z PWM drive. We can't simulate every corner case,
    lightning strikes or major system faults.

    It's just an interesting problem, simulating a pretty high power
    inductor without a hundred pounds of iron. What I'd never thought much
    about is how terrible inductors are at storing energy. Inductor:capacitor:supercap:battery are roughly 1000:1 steps in energy density.





    On the plus side, you can (so to speak) charge and discharge them a good
    1e9 times faster than your average battery.

    Cheers

    Phil Hobbs

    --
    Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to pcdhSpamMeSenseless@electrooptical. on Fri Nov 15 13:08:35 2024
    On Fri, 15 Nov 2024 17:28:18 -0000 (UTC), Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

    john larkin <JL@gct.com> wrote:
    On Fri, 15 Nov 2024 21:28:58 +1100, Chris Jones
    <lugnut808@spam.yahoo.com> wrote:

    On 13/11/2024 9:05 am, john larkin wrote:
    On Tue, 12 Nov 2024 19:44:39 +0100, Jeroen Belleman
    <jeroen@nospam.please> wrote:

    On 11/12/24 16:49, john larkin wrote:
    On Tue, 12 Nov 2024 07:49:13 -0500, legg <legg@nospam.magma.ca> wrote: >>>>>>
    On Sat, 09 Nov 2024 06:08:40 -0800, john larkin <JL@gct.com> wrote: >>>>>>>


    Inductors are awful. Their energy storage is worse than electrolytic >>>>>>>> caps by about a factor of 1000.

    https://electronics.stackexchange.com/questions/326177/energy-density-comparison-between-inductors-and-capacitors

    One could in theory make a switchmode gyrator that would make a >>>>>>>> capacitor look like a programmable-value inductor.

    I have an application for that, but it would take too much engineering >>>>>>>> and runtime complexity to make it worth doing. I guess I'll just have >>>>>>>> to buy a bunch of giant, heavy custom toroids.

    I'm sure that there are other reasons why an inductor
    will be used besides the lack of time/energy/resources
    to 'design them out'.

    Energy storage is just one means to an end.

    RL

    Sure. We want to design some dummy loads that will simulate relays, >>>>>> solenoids, stepper motors, torque motors, with programmable R and L. >>>>>> Seemed to me that using caps to make fake inductors would be a good >>>>>> way to do that.

    It's at least an interesting idea to play with. Maybe we can
    switchmode simulate R+L all at once. We would have to store energy and >>>>>> dissipate power to do that.

    Relays and motors do not behave like simple inductors. For example,
    while a relay armature is moving, the back EMF is high enough to
    make the current _drop_ briefly. Modelling that requires more than
    a simple gyrator.

    Jeroen Belleman

    My customer is building giant rackmount boxes full of heavy inductors
    as part of his dummy loads. We want to replace them.

    Given a generalized switching impedance simulator, I guess one could
    model a DC motor.

    I am considering a powered impedance simulator, not the theoretical
    gyrator. Just sort of a gyrator.


    Many inductive loads can produce kilovolts when switched off suddenly.
    If you build a switched-mode equivalent, unless it contains a large real >>> output inductor, your class-D output stage might need supply rails of
    kilovolts to emulate the real inductor accurately. That sounds expensive. >>
    An electronic load would of course have specified voltage, current,
    and power limits.

    But some of the simulated inductance - a few mH maybe - could be real
    inductors, and they would fly back a bunch. We do need to accept a
    customer PWM drive and sort of behave right.

    I don't think that kilovolt flybacks are common in real areospace
    systems. That could damage wire insulation and interfere with other
    stuff.


    If the load you are emulating contains a TVS or other clamp as part of
    the load, then it would be easier to emulate, but you wouldn't be able
    to emulate the fault condition where the clamp fails open.


    Yes, the customer's drivers have flyback diodes or equivlent, or just
    a continuous low-Z PWM drive. We can't simulate every corner case,
    lightning strikes or major system faults.

    It's just an interesting problem, simulating a pretty high power
    inductor without a hundred pounds of iron. What I'd never thought much
    about is how terrible inductors are at storing energy.
    Inductor:capacitor:supercap:battery are roughly 1000:1 steps in energy
    density.





    On the plus side, you can (so to speak) charge and discharge them a good
    1e9 times faster than your average battery.

    Cheers

    Phil Hobbs

    I haven't sold many of these, but it was interesting to design.

    https://www.highlandtechnology.com/Product/T850

    It uses a SiC fet and the home-wound flyback inductor to make pretty
    nice 7 ns 1400-volt pulses straight from the 48-volt supply.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Tom Del Rosso@21:1/5 to john larkin on Sat Nov 16 07:32:27 2024
    john larkin wrote:
    On Tue, 12 Nov 2024 19:44:39 +0100, Jeroen Belleman

    My customer is building giant rackmount boxes full of heavy inductors
    as part of his dummy loads. We want to replace them.

    Given a generalized switching impedance simulator, I guess one could
    model a DC motor.

    I am considering a powered impedance simulator, not the theoretical
    gyrator. Just sort of a gyrator.

    Better to make it a floating inductor instead of a grounded one like
    gyrators are.

    Bob Pease shows how:

    https://youtu.be/AEJtajaRj_s?t=284

    Turn THAT into a switcher and patent it.


    --
    Defund the Thought Police

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin@21:1/5 to fizzbintuesday@that-google-mail-dom on Sat Nov 16 07:55:07 2024
    On Sat, 16 Nov 2024 07:32:27 -0500, "Tom Del Rosso" <fizzbintuesday@that-google-mail-domain.com> wrote:

    john larkin wrote:
    On Tue, 12 Nov 2024 19:44:39 +0100, Jeroen Belleman

    My customer is building giant rackmount boxes full of heavy inductors
    as part of his dummy loads. We want to replace them.

    Given a generalized switching impedance simulator, I guess one could
    model a DC motor.

    I am considering a powered impedance simulator, not the theoretical
    gyrator. Just sort of a gyrator.

    Better to make it a floating inductor instead of a grounded one like
    gyrators are.

    Bob Pease shows how:

    https://youtu.be/AEJtajaRj_s?t=284

    Turn THAT into a switcher and patent it.

    That's differential but not floating relative to the opamp power
    supplies.

    Every channel will of course need its own dc/dc converter, so it
    really looks like an isolated resistor+inductor to the customer.

    We do that a lot, floating circuits. The Coilcraft planar transformers
    are great for powering isolated stuff.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)