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On 23/11/2022 13:30, Commander Kinsey wrote:
On Wed, 23 Nov 2022 13:13:53 -0000, The Natural Philosopher
tnp@invalid.invalid> wrote:
On 23/11/2022 11:41, Max Demian wrote:
On 23/11/2022 11:14, Commander Kinsey wrote:
On Wed, 23 Nov 2022 10:00:06 -0000, The Natural Philosopher
tnp@invalid.invalid> wrote:
Seawater is a good conductor, unlike air, so the cables must be
insulated, and that insulation forms the bulk of the dielectric.
That\'s why they had to be DC - charging and discharging that
capacitance
via a resistive cable cant be done 50 times a second without massive
losses.
Are all insulators dielectrics?
Potentially.
Ability to form a capacitor is connected to the formation of dipoles in
the material Monopoles are characteristic of conductors.
There must be some insulators which cannot form dipoles.
Only useful if you know what a dipole is, and an insulator.
Of course taking into account, there is no such thing as a perfect
insulator, and no such thing as a perfect conductor, superconductors
excepted.
On Wed, 23 Nov 2022 15:25:10 +0000, Fredxx <fredxx@spam.uk> wrote:
On 23/11/2022 13:30, Commander Kinsey wrote:
On Wed, 23 Nov 2022 13:13:53 -0000, The Natural Philosopher
tnp@invalid.invalid> wrote:
On 23/11/2022 11:41, Max Demian wrote:
On 23/11/2022 11:14, Commander Kinsey wrote:
On Wed, 23 Nov 2022 10:00:06 -0000, The Natural Philosopher
tnp@invalid.invalid> wrote:
Seawater is a good conductor, unlike air, so the cables must be
insulated, and that insulation forms the bulk of the dielectric.
That\'s why they had to be DC - charging and discharging that
capacitance
via a resistive cable cant be done 50 times a second without massive
losses.
Are all insulators dielectrics?
Potentially.
Ability to form a capacitor is connected to the formation of dipoles in
the material Monopoles are characteristic of conductors.
There must be some insulators which cannot form dipoles.
Only useful if you know what a dipole is, and an insulator.
Of course taking into account, there is no such thing as a perfect
insulator, and no such thing as a perfect conductor, superconductors
excepted.
Vacuum is a pretty good non-polar insulator. Er = 1. Insulation
resistance is excellent.
Its breakdown voltage is impressive, but enough voltage gradient will
rip atoms off any metal electrodes. Around 1e10 v/m as I recall.
? Looking at yesterday as a quick example on gridwatch wind is
nowhere near 40%.
On Wed, 23 Nov 2022 15:11:06 +0000, Fredxx <fredxx@spam.uk> wrote:
On 23/11/2022 11:41, Max Demian wrote:
On 23/11/2022 11:14, Commander Kinsey wrote:
On Wed, 23 Nov 2022 10:00:06 -0000, The Natural Philosopher
tnp@invalid.invalid> wrote:
Seawater is a good conductor, unlike air, so the cables must be
insulated, and that insulation forms the bulk of the dielectric.
That\'s why they had to be DC - charging and discharging that capacitance
via a resistive cable cant be done 50 times a second without massive
losses.
Are all insulators dielectrics?
Potentially.
With at least a relative permittivity of unity.
A negative permittivity would be fun, but violates conservation of
energy. Negative capacitors are easy; I did one as a school project
but it had a battery inside.
On Wed, 23 Nov 2022 15:25:10 -0000, Fredxx <fredxx@spam.uk> wrote:
On 23/11/2022 13:30, Commander Kinsey wrote:
On Wed, 23 Nov 2022 13:13:53 -0000, The Natural Philosopher
tnp@invalid.invalid> wrote:
On 23/11/2022 11:41, Max Demian wrote:
On 23/11/2022 11:14, Commander Kinsey wrote:
On Wed, 23 Nov 2022 10:00:06 -0000, The Natural Philosopher
tnp@invalid.invalid> wrote:
Seawater is a good conductor, unlike air, so the cables must be
insulated, and that insulation forms the bulk of the dielectric.
That\'s why they had to be DC - charging and discharging that
capacitance
via a resistive cable cant be done 50 times a second without massive
losses.
Are all insulators dielectrics?
Potentially.
Ability to form a capacitor is connected to the formation of dipoles in
the material Monopoles are characteristic of conductors.
There must be some insulators which cannot form dipoles.
Only useful if you know what a dipole is, and an insulator.
I\'m quite sure the engineers making the inter-country connections do.
Of course taking into account, there is no such thing as a perfect
insulator, and no such thing as a perfect conductor, superconductors
excepted.
It doesn\'t have to a be a perfect insulator, just one that\'s rubbish at
being a dipole.
On 23/11/2022 20:40, Commander Kinsey wrote:
On Wed, 23 Nov 2022 15:25:10 -0000, Fredxx <fredxx@spam.uk> wrote:
On 23/11/2022 13:30, Commander Kinsey wrote:
On Wed, 23 Nov 2022 13:13:53 -0000, The Natural Philosopher
tnp@invalid.invalid> wrote:
On 23/11/2022 11:41, Max Demian wrote:
On 23/11/2022 11:14, Commander Kinsey wrote:
On Wed, 23 Nov 2022 10:00:06 -0000, The Natural Philosopher
tnp@invalid.invalid> wrote:
Seawater is a good conductor, unlike air, so the cables must be
insulated, and that insulation forms the bulk of the dielectric.
That\'s why they had to be DC - charging and discharging that
capacitance
via a resistive cable cant be done 50 times a second without massive
losses.
Are all insulators dielectrics?
Potentially.
Ability to form a capacitor is connected to the formation of dipoles in
the material Monopoles are characteristic of conductors.
There must be some insulators which cannot form dipoles.
Only useful if you know what a dipole is, and an insulator.
I\'m quite sure the engineers making the inter-country connections do.
Of course taking into account, there is no such thing as a perfect
insulator, and no such thing as a perfect conductor, superconductors
excepted.
It doesn\'t have to a be a perfect insulator, just one that\'s rubbish at
being a dipole.
I think we have discovered the problem in your understanding. An
insulator rubbish at being a dipole, would normally be called a conductor.
On 2022-11-23 11:47, Martin Brown wrote:
On 22/11/2022 16:32, John Larkin wrote:
On Tue, 22 Nov 2022 15:38:21 +0000, Clive Page <usenet@page2.eu
wrote:
On 18/11/2022 12:04, Martin Brown wrote:
...
I can\'t imagine anything that would cause a reasonable train
propulsion system to fail at 49 Hz, or even 45 Hz.
The fact that the UK mains distribution grid will drop them off load
at 48Hz has a lot to do with it. They represent a large \"pure\" load
(and so are a target once the usual intermittent supply folk have been
dropped).
Automated load shedding triggers at <48.000Hz.
Snag was that with the modern configuration of local solar panels and
wind shedding 1GW of domestic load also shed 600MW of local generation
so only made a 400MW net contribution. Rinse and repeat leading to a
cascade failure of a much larger section of grid than was strictly
necessary. It will almost certainly fail the same way next time.
Maybe the trains will have a boot from cold function added to their
firmware in future but I\'m not holding my breath.
What happens if they simply lower the Pantograph? I suppose they do that
eventually, when parked.
On Wed, 23 Nov 2022 20:58:37 -0000, Fredxx <fredxx@spam.uk> wrote:
On 23/11/2022 20:40, Commander Kinsey wrote:
On Wed, 23 Nov 2022 15:25:10 -0000, Fredxx <fredxx@spam.uk> wrote:
On 23/11/2022 13:30, Commander Kinsey wrote:
On Wed, 23 Nov 2022 13:13:53 -0000, The Natural Philosopher
tnp@invalid.invalid> wrote:
On 23/11/2022 11:41, Max Demian wrote:
On 23/11/2022 11:14, Commander Kinsey wrote:
On Wed, 23 Nov 2022 10:00:06 -0000, The Natural Philosopher
tnp@invalid.invalid> wrote:
Seawater is a good conductor, unlike air, so the cables must be
insulated, and that insulation forms the bulk of the dielectric.
That\'s why they had to be DC - charging and discharging that
capacitance
via a resistive cable cant be done 50 times a second without massive
losses.
Are all insulators dielectrics?
Potentially.
Ability to form a capacitor is connected to the formation of dipoles in
the material Monopoles are characteristic of conductors.
There must be some insulators which cannot form dipoles.
Only useful if you know what a dipole is, and an insulator.
I\'m quite sure the engineers making the inter-country connections do.
Of course taking into account, there is no such thing as a perfect
insulator, and no such thing as a perfect conductor, superconductors
excepted.
It doesn\'t have to a be a perfect insulator, just one that\'s rubbish at
being a dipole.
I think we have discovered the problem in your understanding. An
insulator rubbish at being a dipole, would normally be called a conductor.
Idiot. Different insulators have different dipole properties.
On Wed, 23 Nov 2022 15:39:19 -0000, John Larkin <jlarkin@highlandsnipmetechnology.com> wrote:
On Wed, 23 Nov 2022 15:11:06 +0000, Fredxx <fredxx@spam.uk> wrote:
On 23/11/2022 11:41, Max Demian wrote:
On 23/11/2022 11:14, Commander Kinsey wrote:
On Wed, 23 Nov 2022 10:00:06 -0000, The Natural Philosopher
tnp@invalid.invalid> wrote:
Seawater is a good conductor, unlike air, so the cables must be
insulated, and that insulation forms the bulk of the dielectric.
That\'s why they had to be DC - charging and discharging that capacitance
via a resistive cable cant be done 50 times a second without massive
losses.
Are all insulators dielectrics?
Potentially.
With at least a relative permittivity of unity.
A negative permittivity would be fun, but violates conservation of
energy. Negative capacitors are easy; I did one as a school project
but it had a battery inside.
https://www.anl.gov/article/newly-devised-static-negative-capacitor-could-improve-computing
On 23/11/2022 13:34, Carlos E.R. wrote:
On 2022-11-23 11:47, Martin Brown wrote:
On 22/11/2022 16:32, John Larkin wrote:
On Tue, 22 Nov 2022 15:38:21 +0000, Clive Page <usenet@page2.eu
wrote:
On 18/11/2022 12:04, Martin Brown wrote:
...
I can\'t imagine anything that would cause a reasonable train
propulsion system to fail at 49 Hz, or even 45 Hz.
The fact that the UK mains distribution grid will drop them off load
at 48Hz has a lot to do with it. They represent a large \"pure\" load
(and so are a target once the usual intermittent supply folk have been
dropped).
Automated load shedding triggers at <48.000Hz.
Snag was that with the modern configuration of local solar panels and
wind shedding 1GW of domestic load also shed 600MW of local generation
so only made a 400MW net contribution. Rinse and repeat leading to a
cascade failure of a much larger section of grid than was strictly
necessary. It will almost certainly fail the same way next time.
Maybe the trains will have a boot from cold function added to their
firmware in future but I\'m not holding my breath.
What happens if they simply lower the Pantograph? I suppose they do that
eventually, when parked.
That\'s a good point. Locos are parked up with their pantographs lowered.
Surely it doesn\'t need an engineer visit to power them back up?
On Wed, 23 Nov 2022 13:13:53 -0000, The Natural Philosopher <tnp@invalid.invalid> wrote:
On 23/11/2022 11:41, Max Demian wrote:
On 23/11/2022 11:14, Commander Kinsey wrote:
On Wed, 23 Nov 2022 10:00:06 -0000, The Natural Philosopher
tnp@invalid.invalid> wrote:
Seawater is a good conductor, unlike air, so the cables must be
insulated, and that insulation forms the bulk of the dielectric.
That\'s why they had to be DC - charging and discharging that capacitance
via a resistive cable cant be done 50 times a second without massive
losses.
Are all insulators dielectrics?
Potentially.
Ability to form a capacitor is connected to the formation of dipoles in
the material Monopoles are characteristic of conductors.
There must be some insulators which cannot form dipoles.
On Wed, 23 Nov 2022 21:10:02 -0000, \"Commander Kinsey\"
C...@nospam.com> wrote:
On Wed, 23 Nov 2022 20:58:37 -0000, Fredxx <fre...@spam.uk> wrote:
On 23/11/2022 20:40, Commander Kinsey wrote:
On Wed, 23 Nov 2022 15:25:10 -0000, Fredxx <fre...@spam.uk> wrote:
On 23/11/2022 13:30, Commander Kinsey wrote:
There must be some insulators which cannot form dipoles.
Only useful if you know what a dipole is, and an insulator.
I\'m quite sure the engineers making the inter-country connections do.
Of course taking into account, there is no such thing as a perfect
insulator, and no such thing as a perfect conductor, superconductors
excepted.
It doesn\'t have to a be a perfect insulator, just one that\'s rubbish at
being a dipole.
I think we have discovered the problem in your understanding. An
insulator rubbish at being a dipole, would normally be called a conductor.
Idiot. Different insulators have different dipole properties.
I don\'t think a monatomic gas is considered to be a dipole, but their
Er > 1.
There\'s nothing new about a cap with a negative incremental c:v slope.
I doubt that one is going to revolutionize computing.
On 2022-11-23, SteveW <steve@walker-family.me.uk> wrote:
On 23/11/2022 13:34, Carlos E.R. wrote:
On 2022-11-23 11:47, Martin Brown wrote:
On 22/11/2022 16:32, John Larkin wrote:
On Tue, 22 Nov 2022 15:38:21 +0000, Clive Page <usenet@page2.eu
wrote:
On 18/11/2022 12:04, Martin Brown wrote:
...
I can\'t imagine anything that would cause a reasonable train
propulsion system to fail at 49 Hz, or even 45 Hz.
The fact that the UK mains distribution grid will drop them off load
at 48Hz has a lot to do with it. They represent a large \"pure\" load
(and so are a target once the usual intermittent supply folk have been
dropped).
Automated load shedding triggers at <48.000Hz.
Snag was that with the modern configuration of local solar panels and
wind shedding 1GW of domestic load also shed 600MW of local generation
so only made a 400MW net contribution. Rinse and repeat leading to a
cascade failure of a much larger section of grid than was strictly
necessary. It will almost certainly fail the same way next time.
Maybe the trains will have a boot from cold function added to their
firmware in future but I\'m not holding my breath.
What happens if they simply lower the Pantograph? I suppose they do that
eventually, when parked.
That\'s a good point. Locos are parked up with their pantographs lowered.
Surely it doesn\'t need an engineer visit to power them back up?
I wonder if the engineers needed were actually train
drivers (which are sometimes called \"engineers\").
On Wed, 23 Nov 2022 17:57:33 -0000, John Larkin
jlarkin@highlandsnipmetechnology.com> wrote:
We\'d be OK without power for a few weeks in our mild climate, but we
have some food and water and a propane BBQ.
Cooking is not required for survival. Power for the freezer and fridge
is handy though.
On 24/11/2022 03:56, Jasen Betts wrote:
On 2022-11-23, SteveW <steve@walker-family.me.uk> wrote:
On 23/11/2022 13:34, Carlos E.R. wrote:
On 2022-11-23 11:47, Martin Brown wrote:
On 22/11/2022 16:32, John Larkin wrote:
On Tue, 22 Nov 2022 15:38:21 +0000, Clive Page <usenet@page2.eu
wrote:
On 18/11/2022 12:04, Martin Brown wrote:
...
I can\'t imagine anything that would cause a reasonable train
propulsion system to fail at 49 Hz, or even 45 Hz.
The fact that the UK mains distribution grid will drop them off load
at 48Hz has a lot to do with it. They represent a large \"pure\" load
(and so are a target once the usual intermittent supply folk have been
dropped).
Automated load shedding triggers at <48.000Hz.
Snag was that with the modern configuration of local solar panels and
wind shedding 1GW of domestic load also shed 600MW of local generation
so only made a 400MW net contribution. Rinse and repeat leading to a
cascade failure of a much larger section of grid than was strictly
necessary. It will almost certainly fail the same way next time.
Maybe the trains will have a boot from cold function added to their
firmware in future but I\'m not holding my breath.
What happens if they simply lower the Pantograph? I suppose they do
that
eventually, when parked.
That\'s a good point. Locos are parked up with their pantographs lowered.
Surely it doesn\'t need an engineer visit to power them back up?
I wonder if the engineers needed were actually train
drivers (which are sometimes called \"engineers\").
Surely the drivers would be stuck with the stranded locos in the first
place? Plus, engineers is not really a term used for British train
drivers, it is more an American term.