Re: switchmode gyrator

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.