Reservoir inductance....

[none]

In a dc-dc transformer we mostly see a reservoir capacitor,
that is charged by some control circuit and decharged by the
application.

What about a reservoir inductance? I know there are problems
with saturation, but OTOH it is easier to pump extra energy
into the inductance because the delta E is the product of the
extra current and the current already present.

Is this being used anywhere? Maybe there is a reason why not?

Groetjes Albert
--
This is the first day of the end of your life.
It may not kill you, but it does make your weaker.
If you can\'t beat them, too bad.
albert@spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst

 

[server]

On 22 Nov 2020 14:12:23 GMT, albert@cherry.(none) (albert) wrote:

In a dc-dc transformer we mostly see a reservoir capacitor,
that is charged by some control circuit and decharged by the
application.

What about a reservoir inductance? I know there are problems
with saturation, but OTOH it is easier to pump extra energy
into the inductance because the delta E is the product of the
extra current and the current already present.

Is this being used anywhere? Maybe there is a reason why not?

Groetjes Albert

Draw a circuit and we\'ll discuss it.



--

John Larkin Highland Technology, Inc

The best designs are necessarily accidental.

 

[legg]

On 22 Nov 2020 14:12:23 GMT, albert@cherry.(none) (albert) wrote:

In a dc-dc transformer we mostly see a reservoir capacitor,
that is charged by some control circuit and decharged by the
application.

What about a reservoir inductance? I know there are problems
with saturation, but OTOH it is easier to pump extra energy
into the inductance because the delta E is the product of the
extra current and the current already present.

Is this being used anywhere? Maybe there is a reason why not?

Groetjes Albert

Scaleability and static loss.

RL

 

[server]

On Sun, 22 Nov 2020 12:38:53 -0500, legg <legg@nospam.magma.ca> wrote:

On 22 Nov 2020 14:12:23 GMT, albert@cherry.(none) (albert) wrote:

In a dc-dc transformer we mostly see a reservoir capacitor,
that is charged by some control circuit and decharged by the
application.

What about a reservoir inductance? I know there are problems
with saturation, but OTOH it is easier to pump extra energy
into the inductance because the delta E is the product of the
extra current and the current already present.

Is this being used anywhere? Maybe there is a reason why not?

Groetjes Albert

Scaleability and static loss.

RL

Some ancient electronics used choke-input filters. Three-phase AC can
be full-wave rectified into an inductive filter, which makes sense in
some applications.



--

John Larkin Highland Technology, Inc

The best designs are necessarily accidental.

 

[Cursitor Doom]

On 22 Nov 2020 14:12:23 GMT, albert@cherry.(none) (albert) wrote:

In a dc-dc transformer we mostly see a reservoir capacitor,
that is charged by some control circuit and decharged by the
application.

What about a reservoir inductance? I know there are problems
with saturation, but OTOH it is easier to pump extra energy
into the inductance because the delta E is the product of the
extra current and the current already present.

Is this being used anywhere? Maybe there is a reason why not?

Cost primarily, I would imagine.

 

[server]

On Sun, 22 Nov 2020 17:59:25 +0000, Cursitor Doom <cd@noreply.com>
wrote:

On 22 Nov 2020 14:12:23 GMT, albert@cherry.(none) (albert) wrote:

In a dc-dc transformer we mostly see a reservoir capacitor,
that is charged by some control circuit and decharged by the
application.

What about a reservoir inductance? I know there are problems
with saturation, but OTOH it is easier to pump extra energy
into the inductance because the delta E is the product of the
extra current and the current already present.

Is this being used anywhere? Maybe there is a reason why not?

Cost primarily, I would imagine.

Most people like their power supplies to have a low output impedance
across the working frequency range.

Switchers do usually store a lot of their energy in inductors.



--

John Larkin Highland Technology, Inc

The best designs are necessarily accidental.

 

[Cursitor Doom]

On Sun, 22 Nov 2020 10:09:26 -0800, jlarkin@highlandsniptechnology.com
wrote:

On Sun, 22 Nov 2020 17:59:25 +0000, Cursitor Doom <cd@noreply.com
wrote:

On 22 Nov 2020 14:12:23 GMT, albert@cherry.(none) (albert) wrote:

In a dc-dc transformer we mostly see a reservoir capacitor,
that is charged by some control circuit and decharged by the
application.

What about a reservoir inductance? I know there are problems
with saturation, but OTOH it is easier to pump extra energy
into the inductance because the delta E is the product of the
extra current and the current already present.

Is this being used anywhere? Maybe there is a reason why not?

Cost primarily, I would imagine.

Most people like their power supplies to have a low output impedance
across the working frequency range.

Switchers do usually store a lot of their energy in inductors.

I\'m wondering what the ESR effects of using inductors for storage vs.
a big ol\' bank of electrolytics. I would have thought there\'d be
adverse consequences ripple-wise at the output, even under light
loads?

 

[Joe Gwinn]

On Sun, 22 Nov 2020 09:58:40 -0800, jlarkin@highlandsniptechnology.com
wrote:

On Sun, 22 Nov 2020 12:38:53 -0500, legg <legg@nospam.magma.ca> wrote:

On 22 Nov 2020 14:12:23 GMT, albert@cherry.(none) (albert) wrote:

In a dc-dc transformer we mostly see a reservoir capacitor,
that is charged by some control circuit and decharged by the
application.

What about a reservoir inductance? I know there are problems
with saturation, but OTOH it is easier to pump extra energy
into the inductance because the delta E is the product of the
extra current and the current already present.

Is this being used anywhere? Maybe there is a reason why not?

Groetjes Albert

Scaleability and static loss.

RL

Some ancient electronics used choke-input filters. Three-phase AC can
be full-wave rectified into an inductive filter, which makes sense in
some applications.

As I recall, the issue was to smooth out the current pulses for a
capacitor-input ripple filter. I think that The Radiotron Designers
Handbook had a chapter on this.

Don\'t forget\" swinging chokes\".


Joe Gwinn

 

[Tim Williams]

That definition might fit a flyback converter and friends?

The transformation you\'re looking for, is: convert all series nodes to
parallel branches and vice versa; swap capacitors and inductors; and swap
voltages with currents.

Therefore the series reservoir inductor smooths current, just as the
parallel reservoir capacitor smooths voltage.

Tim

--
Seven Transistor Labs, LLC
Electrical Engineering Consultation and Design
Website: https://www.seventransistorlabs.com/

\"none (albert)\" <albert@cherry.> wrote in message
news:5fba71c7$0$296$e4fe514c@news.xs4all.nl...

In a dc-dc transformer we mostly see a reservoir capacitor,
that is charged by some control circuit and decharged by the
application.

What about a reservoir inductance? I know there are problems
with saturation, but OTOH it is easier to pump extra energy
into the inductance because the delta E is the product of the
extra current and the current already present.

Is this being used anywhere? Maybe there is a reason why not?

Groetjes Albert
--
This is the first day of the end of your life.
It may not kill you, but it does make your weaker.
If you can\'t beat them, too bad.
albert@spe&ar&c.xs4all.nl &=n http://home.hccnet.nl/a.w.m.van.der.horst

 

[Jeroen Belleman]

On 2020-11-22 15:12, none albert wrote:

In a dc-dc transformer we mostly see a reservoir capacitor,
that is charged by some control circuit and decharged by the
application.

What about a reservoir inductance? I know there are problems
with saturation, but OTOH it is easier to pump extra energy
into the inductance because the delta E is the product of the
extra current and the current already present.

Is this being used anywhere? Maybe there is a reason why not?

Flyback converter?

Jeroen Belleman

 

[bitrex]

On 11/22/2020 12:58 PM, jlarkin@highlandsniptechnology.com wrote:

On Sun, 22 Nov 2020 12:38:53 -0500, legg <legg@nospam.magma.ca> wrote:

On 22 Nov 2020 14:12:23 GMT, albert@cherry.(none) (albert) wrote:

In a dc-dc transformer we mostly see a reservoir capacitor,
that is charged by some control circuit and decharged by the
application.

What about a reservoir inductance? I know there are problems
with saturation, but OTOH it is easier to pump extra energy
into the inductance because the delta E is the product of the
extra current and the current already present.

Is this being used anywhere? Maybe there is a reason why not?

Groetjes Albert

Scaleability and static loss.

RL

Some ancient electronics used choke-input filters. Three-phase AC can
be full-wave rectified into an inductive filter, which makes sense in
some applications.

In olden times they sometimes used a common-mode choke and ran the
device filament current through the other winding to reduce its size.

I remember seeing a patent on this technique from about 1925 but can\'t
find it atm

 

[John Larkin]

On Sun, 22 Nov 2020 15:11:17 -0500, Joe Gwinn <joegwinn@comcast.net>
wrote:

On Sun, 22 Nov 2020 09:58:40 -0800, jlarkin@highlandsniptechnology.com
wrote:

On Sun, 22 Nov 2020 12:38:53 -0500, legg <legg@nospam.magma.ca> wrote:

On 22 Nov 2020 14:12:23 GMT, albert@cherry.(none) (albert) wrote:

In a dc-dc transformer we mostly see a reservoir capacitor,
that is charged by some control circuit and decharged by the
application.

What about a reservoir inductance? I know there are problems
with saturation, but OTOH it is easier to pump extra energy
into the inductance because the delta E is the product of the
extra current and the current already present.

Is this being used anywhere? Maybe there is a reason why not?

Groetjes Albert

Scaleability and static loss.

RL

Some ancient electronics used choke-input filters. Three-phase AC can
be full-wave rectified into an inductive filter, which makes sense in
some applications.

As I recall, the issue was to smooth out the current pulses for a
capacitor-input ripple filter. I think that The Radiotron Designers
Handbook had a chapter on this.

Don\'t forget\" swinging chokes\".


Joe Gwinn

I suppose big capacitors were expensive in olden times, so inductors
made sense.

Tubes were expensive too, hence interstage transformers for voltage
gain.

Someone could prowl Digikey and calculate joules/dollar for some
inductors and caps.

 

[whit3rd]

On Sunday, November 22, 2020 at 6:12:32 AM UTC-8, none albert wrote:

In a dc-dc transformer we mostly see a reservoir capacitor,
that is charged by some control circuit and decharged by the
application.

What about a reservoir inductance? I know there are problems
with saturation, but OTOH it is easier to pump extra energy
into the inductance because the delta E is the product of the
extra current and the current already present.

Is this being used anywhere? Maybe there is a reason why not?

Yes, by the megawatt, in aluminum refining by electrolysis. There\'s too
much current for a single diode, so you parallel the diodes, and
use inductive pass-through to keep the hottest one from hogging the
current. The trick is, inductive energy storage works best in LOW impedance
(high current, low voltage) circuitry, and doesn\'t like dI/dt (which can
be huge in a clocked digital system), so only unregulated-volt/high-current
applications seem appropriate.

The elusive room-temperature superconductor might change the breakeven
points, sometime in the coming century.

 

[legg]

On Sun, 22 Nov 2020 12:19:44 -0800, John Larkin
<jlarkin@highland_atwork_technology.com> wrote:

On Sun, 22 Nov 2020 15:11:17 -0500, Joe Gwinn <joegwinn@comcast.net
wrote:

On Sun, 22 Nov 2020 09:58:40 -0800, jlarkin@highlandsniptechnology.com
wrote:

On Sun, 22 Nov 2020 12:38:53 -0500, legg <legg@nospam.magma.ca> wrote:

On 22 Nov 2020 14:12:23 GMT, albert@cherry.(none) (albert) wrote:

In a dc-dc transformer we mostly see a reservoir capacitor,
that is charged by some control circuit and decharged by the
application.

What about a reservoir inductance? I know there are problems
with saturation, but OTOH it is easier to pump extra energy
into the inductance because the delta E is the product of the
extra current and the current already present.

Is this being used anywhere? Maybe there is a reason why not?

Groetjes Albert

Scaleability and static loss.

RL

Some ancient electronics used choke-input filters. Three-phase AC can
be full-wave rectified into an inductive filter, which makes sense in
some applications.

As I recall, the issue was to smooth out the current pulses for a
capacitor-input ripple filter. I think that The Radiotron Designers
Handbook had a chapter on this.

Don\'t forget\" swinging chokes\".


Joe Gwinn


I suppose big capacitors were expensive in olden times, so inductors
made sense.

Tubes were expensive too, hence interstage transformers for voltage
gain.

Someone could prowl Digikey and calculate joules/dollar for some
inductors and caps.

The issue was mostly rectifier capability. That\'s why the \'current
doubler\' or hybridge circuit was developed during the reign of the
mercury rectifier; only to be rediscovered in the times of commodity
100A processor supplies.

For energy storage, I\'d assumed the OP was interested in time scales
greater than two cycles of the mains frequency.

RL

 

[Bill Sloman]

On Monday, November 23, 2020 at 9:51:39 AM UTC+11, whit3rd wrote:

On Sunday, November 22, 2020 at 6:12:32 AM UTC-8, none albert wrote:
In a dc-dc transformer we mostly see a reservoir capacitor,
that is charged by some control circuit and decharged by the
application.

What about a reservoir inductance? I know there are problems
with saturation, but OTOH it is easier to pump extra energy
into the inductance because the delta E is the product of the
extra current and the current already present.

Is this being used anywhere? Maybe there is a reason why not?
Yes, by the megawatt, in aluminum refining by electrolysis. There\'s too
much current for a single diode, so you parallel the diodes, and
use inductive pass-through to keep the hottest one from hogging the
current. The trick is, inductive energy storage works best in LOW impedance
(high current, low voltage) circuitry, and doesn\'t like dI/dt (which can
be huge in a clocked digital system), so only unregulated-volt/high-current
applications seem appropriate.

The elusive room-temperature superconductor might change the breakeven
points, sometime in the coming century.

Someone has found a superconductor that super-conducts up to 17 Celcius, which is almost room temperature. You have compress it quite hard to get super-conductivity - an appreciable proportion of the pressure at the earth\'s core, so it got demonstrated on a very small scale in a diamond anvil compression cell. You couldn\'t store much energy in that.

--
Bill Sloman, Sydney

 

[Sylvia Else]

On 23-Nov-20 1:12 am, albert wrote:

In a dc-dc transformer we mostly see a reservoir capacitor,
that is charged by some control circuit and decharged by the
application.

What about a reservoir inductance? I know there are problems
with saturation, but OTOH it is easier to pump extra energy
into the inductance because the delta E is the product of the
extra current and the current already present.

Is this being used anywhere? Maybe there is a reason why not?

Groetjes Albert

It cannot be the energy store feeding the application circuit, because
any attempt by the application to reduce its current draw abruptly would
result in the input voltage going up.

Sylvia.

 

[server]

On Sun, 22 Nov 2020 15:11:17 -0500, Joe Gwinn <joegwinn@comcast.net>
wrote:

Some ancient electronics used choke-input filters. Three-phase AC can
be full-wave rectified into an inductive filter, which makes sense in
some applications.

As I recall, the issue was to smooth out the current pulses for a
capacitor-input ripple filter. I think that The Radiotron Designers
Handbook had a chapter on this.

Don\'t forget\" swinging chokes\".

Tube rectifiers do not like high peak currents (limited emission,
large voltage drop). Using LC or CLC input filters extended the
conduction angle, hence reducing the peak current.

 

[legg]

On Mon, 23 Nov 2020 13:40:13 +1100, Sylvia Else <sylvia@email.invalid>
wrote:

On 23-Nov-20 1:12 am, albert wrote:
In a dc-dc transformer we mostly see a reservoir capacitor,
that is charged by some control circuit and decharged by the
application.

What about a reservoir inductance? I know there are problems
with saturation, but OTOH it is easier to pump extra energy
into the inductance because the delta E is the product of the
extra current and the current already present.

Is this being used anywhere? Maybe there is a reason why not?

Groetjes Albert


It cannot be the energy store feeding the application circuit, because
any attempt by the application to reduce its current draw abruptly would
result in the input voltage going up.

Sylvia.

For inductive storage, the \'storing state\' is a short circuit across
its terminals.

RL

 

[server]

On Mon, 23 Nov 2020 13:40:13 +1100, Sylvia Else <sylvia@email.invalid>
wrote:

On 23-Nov-20 1:12 am, albert wrote:
In a dc-dc transformer we mostly see a reservoir capacitor,
that is charged by some control circuit and decharged by the
application.

What about a reservoir inductance? I know there are problems
with saturation, but OTOH it is easier to pump extra energy
into the inductance because the delta E is the product of the
extra current and the current already present.

Is this being used anywhere? Maybe there is a reason why not?

Groetjes Albert


It cannot be the energy store feeding the application circuit, because
any attempt by the application to reduce its current draw abruptly would
result in the input voltage going up.

Sylvia.

Many of our laser drivers use inductive energy storage.



--

John Larkin Highland Technology, Inc

The best designs are necessarily accidental.

 

[Sjouke Burry]

On 23.11.20 16:44, jlarkin@highlandsniptechnology.com wrote:

On Mon, 23 Nov 2020 13:40:13 +1100, Sylvia Else <sylvia@email.invalid
wrote:

On 23-Nov-20 1:12 am, albert wrote:
In a dc-dc transformer we mostly see a reservoir capacitor,
that is charged by some control circuit and decharged by the
application.

What about a reservoir inductance? I know there are problems
with saturation, but OTOH it is easier to pump extra energy
into the inductance because the delta E is the product of the
extra current and the current already present.

Is this being used anywhere? Maybe there is a reason why not?

Groetjes Albert


It cannot be the energy store feeding the application circuit, because
any attempt by the application to reduce its current draw abruptly would
result in the input voltage going up.

Sylvia.

Many of our laser drivers use inductive energy storage.

Jabbut a laser is mostly a current consumer.