I have just seen an advert for teaching in further education. It includes
the compulsory mix of people from various different galaxies to satisfy
the woke brigade.
There was a young lady withdrawing from under an EV bonnet with a
voltmeter in her hand saying "the voltage is 10 volts, down from 600".
Does that make sense, are there EVs somehow running on 600 volt power supplies?
I have just seen an advert for teaching in further education. It includes
the compulsory mix of people from various different galaxies to satisfy
the woke brigade.
There was a young lady withdrawing from under an EV bonnet with a
voltmeter in her hand saying "the voltage is 10 volts, down from 600".
Does that make sense, are there EVs somehow running on 600 volt power supplies?
I have just seen an advert for teaching in further education. It
includes the compulsory mix of people from various different galaxies to satisfy the woke brigade.
There was a young lady withdrawing from under an EV bonnet with a
voltmeter in her hand saying "the voltage is 10 volts, down from 600".
Does that make sense, are there EVs somehow running on 600 volt power supplies?
Lets say you want 180 bhp. That comes to around 240kW
Does that make sense, are there EVs somehow running on 600 volt power >supplies?
On 13/02/2025 in message <xn0p20kbt1xc9hz002@news.individual.net> Jeffand an internal combustion engine to provide most of the bhp :)
Gaines wrote:
Does that make sense, are there EVs somehow running on 600 volt power
supplies?
Many thanks for the replies Theo/Tim Streater/TNP :-)
I am astonished, I had no idea that sort of voltage was involved. I have
a Suzuki mild hybrid which uses 48 volt battery under the passenger
seat
On 13/02/2025 in message <xn0p20kbt1xc9hz002@news.individual.net> Jeff
Gaines wrote:
Does that make sense, are there EVs somehow running on 600 volt power
supplies?
Many thanks for the replies Theo/Tim Streater/TNP :-)
I am astonished, I had no idea that sort of voltage was involved. I have a Suzuki mild hybrid which uses 48 volt battery under the passenger seat
and had imagined that was the norm.
Thanks for the info!
On 14/02/2025 03:05, The Natural Philosopher wrote:
Lets say you want 180 bhp. That comes to around 240kW
Another little detail ?
Lets say you want 180 bhp. That comes to around 240kW
On 14/02/2025 08:41, Jeff Gaines wrote:
On 13/02/2025 in message <xn0p20kbt1xc9hz002@news.individual.net> Jeff >>Gaines wrote:and an internal combustion engine to provide most of the bhp :)
Does that make sense, are there EVs somehow running on 600 volt power >>>supplies?
Many thanks for the replies Theo/Tim Streater/TNP :-)
I am astonished, I had no idea that sort of voltage was involved. I have
a Suzuki mild hybrid which uses 48 volt battery under the passenger
seat
--
Jeff Gaines Dorset UK
640k ought to be enough for anyone.
(Bill Gates, 1981)
On 13/02/2025 in message <xn0p20kbt1xc9hz002@news.individual.net> Jeff
Gaines wrote:
[quoted text muted]
Many thanks for the replies Theo/Tim Streater/TNP
I am astonished, I had no idea that sort of voltage was involved.
On 14/02/2025 08:41, Jeff Gaines wrote:
On 13/02/2025 in message <xn0p20kbt1xc9hz002@news.individual.net> Jeff
Gaines wrote:
Does that make sense, are there EVs somehow running on 600 volt power
supplies?
Many thanks for the replies Theo/Tim Streater/TNP :-)
I am astonished, I had no idea that sort of voltage was involved. I have a >> Suzuki mild hybrid which uses 48 volt battery under the passenger seat
and had imagined that was the norm.
Thanks for the info!
I'd known about the high voltage involved, but one thing I'd never
thought about (because high-voltage DC was rare before EVs) is the issue
of any arc forming. These are more difficult to extinguish than AC arcs,
so I wondered if anybody knew if any special precautions are taken with
EV circuitry to deal with DC arcs if they form. If so, what might they be?
and an internal combustion engine to provide most of the bhp :)
Hallelujah for the IC engine. I am considering a new car, small enough to
fit my 1980's garage. Any suggestions, IC only and about Kia Picanto size, welcome!
On 14/02/2025 in message <m18hvbF5jr8U1@mid.individual.net> alan_m wrote:
On 14/02/2025 08:41, Jeff Gaines wrote:
On 13/02/2025 in message <xn0p20kbt1xc9hz002@news.individual.net> Jeff >>>Gaines wrote:and an internal combustion engine to provide most of the bhp :)
Does that make sense, are there EVs somehow running on 600 volt power >>>>supplies?
Many thanks for the replies Theo/Tim Streater/TNP :-)
I am astonished, I had no idea that sort of voltage was involved. I have >>>a Suzuki mild hybrid which uses 48 volt battery under the passenger
seat
Hallelujah for the IC engine. I am considering a new car, small enough to
fit my 1980's garage. Any suggestions, IC only and about Kia Picanto size, >welcome!
On 2025-02-14 09:00, Nick Finnigan wrote:Oh shit. Had it upside down...My bad
On 14/02/2025 03:05, The Natural Philosopher wrote:
Lets say you want 180 bhp. That comes to around 240kW
Another little detail ?
180 BHP = 134 kW !!
nib
On 14/02/2025 08:41, Jeff Gaines wrote:
On 13/02/2025 in message <xn0p20kbt1xc9hz002@news.individual.net> Jeff Gaines wrote:
Does that make sense, are there EVs somehow running on 600 volt power
supplies?
Many thanks for the replies Theo/Tim Streater/TNP :-)
I am astonished, I had no idea that sort of voltage was involved. I have a Suzuki mild hybrid which uses 48 volt battery under the passenger seat
and had imagined that was the norm.
Thanks for the info!
I'd known about the high voltage involved, but one thing I'd never
thought about (because high-voltage DC was rare before EVs) is the issue
of any arc forming. These are more difficult to extinguish than AC arcs,
so I wondered if anybody knew if any special precautions are taken with
EV circuitry to deal with DC arcs if they form. If so, what might they be?
On Fri, 14 Feb 2025 10:09:45 +0000, Jeff Layman <Jeff@invalid.invalid>
wrote:
On 14/02/2025 08:41, Jeff Gaines wrote:
On 13/02/2025 in message <xn0p20kbt1xc9hz002@news.individual.net> Jeff
Gaines wrote:
Does that make sense, are there EVs somehow running on 600 volt power >>>> supplies?
Many thanks for the replies Theo/Tim Streater/TNP :-)
I am astonished, I had no idea that sort of voltage was involved. I have a >>> Suzuki mild hybrid which uses 48 volt battery under the passenger seat
and had imagined that was the norm.
Thanks for the info!
I'd known about the high voltage involved, but one thing I'd never
thought about (because high-voltage DC was rare before EVs) is the issue
of any arc forming. These are more difficult to extinguish than AC arcs,
so I wondered if anybody knew if any special precautions are taken with
EV circuitry to deal with DC arcs if they form. If so, what might they be?
My simple understanding of these things is that with AC voltages, you
have a bit of cunning circuitry that detects when the voltage passes
through zero (and hence the current also) and switches off at that
point. Back EMF, caused by the dying current (V = DI/DT) and which is
in turn responsible for the spark, is thus zero at that moment, and
because V is zero, hence no spark. But with DC, current is always at
the maximum, so DI/DT is at its maximum, and hence a big spark to try
and maintain that current (Le Chatelier's principle).
But I'm sure it's more complicated than that! Someone will be along in
a few seconds to correct me.
The rather egregious plugging of EVs by people like Prof. Hannah FryIt is surprising how marrow most academics are. One tutor I had knew all
being a case in hand. There is no way she can't not know how shite they
are.
Jeff Layman <Jeff@invalid.invalid> wrote:
On 14/02/2025 08:41, Jeff Gaines wrote:
On 13/02/2025 in message <xn0p20kbt1xc9hz002@news.individual.net> Jeff
Gaines wrote:
Does that make sense, are there EVs somehow running on 600 volt power >>>> supplies?
Many thanks for the replies Theo/Tim Streater/TNP :-)
I am astonished, I had no idea that sort of voltage was involved. I have a >>> Suzuki mild hybrid which uses 48 volt battery under the passenger seat
and had imagined that was the norm.
Thanks for the info!
I'd known about the high voltage involved, but one thing I'd never
thought about (because high-voltage DC was rare before EVs) is the issue
of any arc forming. These are more difficult to extinguish than AC arcs,
so I wondered if anybody knew if any special precautions are taken with
EV circuitry to deal with DC arcs if they form. If so, what might they be?
There's precharge circuitry. You get an arc because there's a potential difference between two points (let's say 400V dc and 0V), enough to ionise the air between them and cause a low resistance path. Current flows, more ionisation happens, and it becomes self-sustaining.
What the circuits do when switching is to establish a low current path
first. So you have one terminal at 400V and another at 0V. You apply a
high resistance path to bring up the second terminal to 400V at a low current. Because it's low current it's not enough to sustain an arc.
Now there's 400V on both terminals and so minimal potential difference between them. Next you close the main contactor and the high current connection is made. Because both sides are at 400V there's no potential difference across the contactor and so no arc is formed as it closes.
Since the motor/inverters are software controlled, you also arrange that there's no current being drawn when opening/closing contactors, both to
avoid pulling arc currents and welding contactor terminals.
Theo
Are there actually any contactors at all in a BEV?
I would assume its 100% solid state.
On 14/02/2025 08:41, Jeff Gaines wrote:
On 13/02/2025 in message <xn0p20kbt1xc9hz002@news.individual.net> Jeff
Gaines wrote:
Does that make sense, are there EVs somehow running on 600 volt power
supplies?
Many thanks for the replies Theo/Tim Streater/TNP :-)
I am astonished, I had no idea that sort of voltage was involved. I
have a
Suzuki mild hybrid which uses 48 volt battery under the passenger seat
and had imagined that was the norm.
Thanks for the info!
I'd known about the high voltage involved, but one thing I'd never
thought about (because high-voltage DC was rare before EVs) is the issue
of any arc forming. These are more difficult to extinguish than AC arcs,
so I wondered if anybody knew if any special precautions are taken with
EV circuitry to deal with DC arcs if they form. If so, what might they be?
Are there actually any contactors at all in a BEV?
On 14/02/2025 10:23, Jethro_uk wrote:
The rather egregious plugging of EVs by people like Prof. Hannah FryIt is surprising how marrow most academics are. One tutor I had knew all >there was to know about prestressed reinforced concrete, and very little >else.
being a case in hand. There is no way she can't not know how shite they
are.
the lovely Hannah+1
But with DC, current is always at the maximum, so DI/DT is at its maximum ...
On Fri, 14 Feb 2025 08:41:49 +0000, Jeff Gaines wrote:
On 13/02/2025 in message <xn0p20kbt1xc9hz002@news.individual.net> Jeff
Gaines wrote:
[quoted text muted]
Many thanks for the replies Theo/Tim Streater/TNP
I am astonished, I had no idea that sort of voltage was involved.
It could be deduced from some basic knowledge:
you are going to need a few horsepower for a car to move. Each horsepower being *roughly* 750W but for speed 1kW will do.
A modest 50horsepower car is therefore 50kW.
On 14 Feb 2025 12:19:14 GMT, Tim Streater <tim@streater.me.uk> wrote:
On 14 Feb 2025 at 10:44:43 GMT, "Chris Hogg" <me@privacy.net> wrote:
But with DC, current is always at the maximum, so DI/DT is at its maximum ...
If the current is at its maximum, i.e. not varying, then di/dt = 0.
If I is at its maximum, and the circuit is suddenly switched off, I
goes to zero very fast, and dI/dT is thus very high.
On 14/02/2025 08:41, Jeff Gaines wrote:
On 13/02/2025 in message <xn0p20kbt1xc9hz002@news.individual.net> Jeff
Gaines wrote:
Does that make sense, are there EVs somehow running on 600 volt power
supplies?
Many thanks for the replies Theo/Tim Streater/TNP :-)
I am astonished, I had no idea that sort of voltage was involved. I
have a
Suzuki mild hybrid which uses 48 volt battery under the passenger seat
and had imagined that was the norm.
Thanks for the info!
I'd known about the high voltage involved, but one thing I'd never
thought about (because high-voltage DC was rare before EVs) is the issue
of any arc forming. These are more difficult to extinguish than AC arcs,
so I wondered if anybody knew if any special precautions are taken with
EV circuitry to deal with DC arcs if they form. If so, what might they be?
On 14/02/2025 10:23, Jethro_uk wrote:
On Fri, 14 Feb 2025 08:41:49 +0000, Jeff Gaines wrote:
On 13/02/2025 in message <xn0p20kbt1xc9hz002@news.individual.net> Jeff
Gaines wrote:
[quoted text muted]
Many thanks for the replies Theo/Tim Streater/TNP
I am astonished, I had no idea that sort of voltage was involved.
It could be deduced from some basic knowledge:
you are going to need a few horsepower for a car to move. Each horsepower
being *roughly* 750W but for speed 1kW will do.
A modest 50horsepower car is therefore 50kW.
*Very* modest.
Before WW2 manufacturers use to brag about 10 or 12 horsepower, but they
used a formula based on cylinder size and so on which became out of
date, so they were much more than that.
My 175cc Honda m/c was rated at "20PS" which is about 20HP.
I like Rolls Royce saying that their power was "adequate".
On 14 Feb 2025 at 10:44:43 GMT, "Chris Hogg" <me@privacy.net> wrote:
But with DC, current is always at the maximum, so DI/DT is at its maximum ...
If the current is at its maximum, i.e. not varying, then di/dt = 0.
On 14 Feb 2025 12:19:14 GMT, Tim Streater <tim@streater.me.uk> wrote:
On 14 Feb 2025 at 10:44:43 GMT, "Chris Hogg" <me@privacy.net> wrote:
But with DC, current is always at the maximum, so DI/DT is at its maximum ...
If the current is at its maximum, i.e. not varying, then di/dt = 0.
If I is at its maximum, and the circuit is suddenly switched off, I
goes to zero very fast, and dI/dT is thus very high.
On 14/02/2025 12:31, Chris Hogg wrote:
On 14 Feb 2025 12:19:14 GMT, Tim Streater <tim@streater.me.uk> wrote:
On 14 Feb 2025 at 10:44:43 GMT, "Chris Hogg" <me@privacy.net> wrote:
But with DC, current is always at the maximum, so DI/DT is at its maximum ...
If the current is at its maximum, i.e. not varying, then di/dt = 0.
If I is at its maximum, and the circuit is suddenly switched off, I
goes to zero very fast, and dI/dT is thus very high.
Except it doesn't work like that. There is inductance and capacitance
all over the place.
The motors are all AC, and lord knows there have to be massive clamp
diodes to take care of breaking any inductive circuits
Electric cars are superb pieces of engineering. The one problem is the battery. Unless you know how electrochemistry works, and its a narrow discipline, you might believe that 'one day batteries will be ten times better' despite this breaking the laws of physics.
The Natural Philosopher <tnp@invalid.invalid> wrote:
On 14/02/2025 12:31, Chris Hogg wrote:
On 14 Feb 2025 12:19:14 GMT, Tim Streater <tim@streater.me.uk> wrote:
On 14 Feb 2025 at 10:44:43 GMT, "Chris Hogg" <me@privacy.net> wrote:
But with DC, current is always at the maximum, so DI/DT is at its
maximum ...
If the current is at its maximum, i.e. not varying, then di/dt = 0.
If I is at its maximum, and the circuit is suddenly switched off, I
goes to zero very fast, and dI/dT is thus very high.
Except it doesn't work like that. There is inductance and capacitance
all over the place.
The motors are all AC, and lord knows there have to be massive clamp diodes to take care of breaking any inductive circuits
They're three phase variable-voltage variable-frequency drives. There
will no doubt be snubber networks to control transients as the
MOSFETs/IGBTs turn on and off. The aim being to commutate the current
through the windings so there aren't any sharp edges (which would cause
EMI, amongst other undesirable effects).
On 14/02/2025 10:23, Jethro_uk wrote:
[quoted text muted]
*Very* modest.
Jeff Layman <Jeff@invalid.invalid> wrote:
On 14/02/2025 08:41, Jeff Gaines wrote:
On 13/02/2025 in message <xn0p20kbt1xc9hz002@news.individual.net> Jeff
Gaines wrote:
Does that make sense, are there EVs somehow running on 600 volt power >>> supplies?
Many thanks for the replies Theo/Tim Streater/TNP :-)
I am astonished, I had no idea that sort of voltage was involved. I have a >> Suzuki mild hybrid which uses 48 volt battery under the passenger seat
and had imagined that was the norm.
Thanks for the info!
I'd known about the high voltage involved, but one thing I'd never
thought about (because high-voltage DC was rare before EVs) is the issue
of any arc forming. These are more difficult to extinguish than AC arcs,
so I wondered if anybody knew if any special precautions are taken with
EV circuitry to deal with DC arcs if they form. If so, what might they be?
Dunno about arcing precautions but the first plug in Kuga I had was subject to a recall due to some issue with charging the batteries. When it went in
to have the batteries changed it had to be parked in one corner of the
garage with barriers erected to stop anyone touching it and a guy had to
come all the way from Germany to disconnect everything and make it safe. It did make me wonder why it was safe for me to drive it about for several months beforehand yet it needed such elaborate precautions once in the garage?
On 14/02/2025 08:41, Jeff Gaines wrote:
On 13/02/2025 in message <xn0p20kbt1xc9hz002@news.individual.net> Jeff
Gaines wrote:
Does that make sense, are there EVs somehow running on 600 volt power
supplies?
Many thanks for the replies Theo/Tim Streater/TNP :-)
I am astonished, I had no idea that sort of voltage was involved. I have a >> Suzuki mild hybrid which uses 48 volt battery under the passenger seat
and had imagined that was the norm.
Thanks for the info!
I'd known about the high voltage involved, but one thing I'd never
thought about (because high-voltage DC was rare before EVs) is the issue
of any arc forming. These are more difficult to extinguish than AC arcs,
so I wondered if anybody knew if any special precautions are taken with
EV circuitry to deal with DC arcs if they form. If so, what might they be?
In article <gSD*Ah96z@news.chiark.greenend.org.uk>, Theo <theom+news@chiark.greenend.org.uk> wrote:
The Natural Philosopher <tnp@invalid.invalid> wrote:
On 14/02/2025 12:31, Chris Hogg wrote:
On 14 Feb 2025 12:19:14 GMT, Tim Streater <tim@streater.me.uk> wrote:
On 14 Feb 2025 at 10:44:43 GMT, "Chris Hogg" <me@privacy.net> wrote: >>
But with DC, current is always at the maximum, so DI/DT is at its
maximum ...
If the current is at its maximum, i.e. not varying, then di/dt = 0.
If I is at its maximum, and the circuit is suddenly switched off, I goes to zero very fast, and dI/dT is thus very high.
Except it doesn't work like that. There is inductance and capacitance
all over the place.
The motors are all AC, and lord knows there have to be massive clamp diodes to take care of breaking any inductive circuits
They're three phase variable-voltage variable-frequency drives. There
will no doubt be snubber networks to control transients as the MOSFETs/IGBTs turn on and off. The aim being to commutate the current through the windings so there aren't any sharp edges (which would cause EMI, amongst other undesirable effects).
Certainly I've never heard any noises on the radio attribuable to the drive.
On 14/02/2025 10:09, Jeff Layman wrote:
On 14/02/2025 08:41, Jeff Gaines wrote:The secret is to have no mechanical switches at all. Except maybe a last-ditch fusible link
On 13/02/2025 in message <xn0p20kbt1xc9hz002@news.individual.net> Jeff
Gaines wrote:
Does that make sense, are there EVs somehow running on 600 volt power >>>> supplies?
Many thanks for the replies Theo/Tim Streater/TNP :-)
I am astonished, I had no idea that sort of voltage was involved. I
have a
Suzuki mild hybrid which uses 48 volt battery under the passenger seat >>> and had imagined that was the norm.
Thanks for the info!
I'd known about the high voltage involved, but one thing I'd never
thought about (because high-voltage DC was rare before EVs) is the
issue of any arc forming. These are more difficult to extinguish than
AC arcs, so I wondered if anybody knew if any special precautions are
taken with EV circuitry to deal with DC arcs if they form. If so, what
might they be?
Motors are brushless. Controllers are solid state. I would imagine that
there is a separate low voltage circuit for all the instruments and
other stuff like windows and lights
charles <charles@candehope.me.uk> wrote:
In article <gSD*Ah96z@news.chiark.greenend.org.uk>, Theo <theom+news@chiark.greenend.org.uk> wrote:
The Natural Philosopher <tnp@invalid.invalid> wrote:
On 14/02/2025 12:31, Chris Hogg wrote:
On 14 Feb 2025 12:19:14 GMT, Tim Streater <tim@streater.me.uk>
wrote:
On 14 Feb 2025 at 10:44:43 GMT, "Chris Hogg" <me@privacy.net>
wrote:
But with DC, current is always at the maximum, so DI/DT is at
its maximum ...
If the current is at its maximum, i.e. not varying, then di/dt =
0.
If I is at its maximum, and the circuit is suddenly switched off,
I goes to zero very fast, and dI/dT is thus very high.
Except it doesn't work like that. There is inductance and
capacitance all over the place.
The motors are all AC, and lord knows there have to be massive
clamp diodes to take care of breaking any inductive circuits
They're three phase variable-voltage variable-frequency drives. There will no doubt be snubber networks to control transients as the MOSFETs/IGBTs turn on and off. The aim being to commutate the current through the windings so there aren't any sharp edges (which would
cause EMI, amongst other undesirable effects).
Certainly I've never heard any noises on the radio attribuable to the drive.
https://www.vice.com/en/article/why-electric-cars-are-ditching-am-radio/
On 14/02/2025 in message <m18hvbF5jr8U1@mid.individual.net> alan_m wrote:
On 14/02/2025 08:41, Jeff Gaines wrote:
On 13/02/2025 in message <xn0p20kbt1xc9hz002@news.individual.net> Jeffand an internal combustion engine to provide most of the bhp :)
Gaines wrote:
Does that make sense, are there EVs somehow running on 600 volt power >>>> supplies?
Many thanks for the replies Theo/Tim Streater/TNP :-)
I am astonished, I had no idea that sort of voltage was involved. I have >>> a Suzuki mild hybrid which uses 48 volt battery under the passenger
seat
Hallelujah for the IC engine. I am considering a new car, small enough to
fit my 1980's garage. Any suggestions, IC only and about Kia Picanto size, welcome!
Jeff Gaines <jgnewsid@outlook.com> wrote:
Hallelujah for the IC engine. I am considering a new car, small enough to fit my 1980's garage. Any suggestions, IC only and about Kia Picanto size, welcome!
We bought a Toyota Aygo as a second car just over 3 years ago, it serves as Senior Management’s Car and we tow it ( on a trailer) behind our motorhome - it is one of the lightest cars in its class.
We are very pleased with it. It came with a 3 year warranty but, if you
have it serviced by Toyota, they extend it every year up to 10 years.
Brian <noinv@lid.org> wrote:
Jeff Gaines <jgnewsid@outlook.com> wrote:
Hallelujah for the IC engine. I am considering a new car, small enough to >>> fit my 1980's garage. Any suggestions, IC only and about Kia Picanto size, >>> welcome!
We bought a Toyota Aygo as a second car just over 3 years ago, it serves as >> Senior Management’s Car and we tow it ( on a trailer) behind our motorhome >> - it is one of the lightest cars in its class.
We are very pleased with it. It came with a 3 year warranty but, if you
have it serviced by Toyota, they extend it every year up to 10 years.
The Aygo / Peugeot 107 / Citroen C1 (all the same car) has a solid
reputation for reliability too. The semi-auto gearbox is annoying though - better to go for the manual.
The new one is the Aygo X which has more plastic trim to make it more crossover-y, if that's your thing.
Fuel economy is very good. Around town ( which is our normal use) 46 mpg.
On a clear run, nearer 50. Plus, ours came with a spare wheel.
I'd known about the high voltage involved, but one thing I'd never
thought about (because high-voltage DC was rare before EVs) is the issue
of any arc forming. These are more difficult to extinguish than AC arcs,
so I wondered if anybody knew if any special precautions are taken with
EV circuitry to deal with DC arcs if they form. If so, what might they be?
Brian <noinv@lid.org> wrote:
Fuel economy is very good. Around town ( which is our normal use) 46 mpg. On a clear run, nearer 50. Plus, ours came with a spare wheel.
For a tiny lightweight car that’s really rather abysmal. My wife’s diesel 4WD Yeti does 50-60 mpg.
The very first cars ever made - in the 1800s - were electric. If only
someone had bothered to do some frankly primary school research into why
they did not take off. It would have saved trillions - and more
importantly a fucktonne of public goodwill.
In article <gSD*Ah96z@news.chiark.greenend.org.uk>, Theo <theom+news@chiark.greenend.org.uk> wrote:
The Natural Philosopher <tnp@invalid.invalid> wrote:
On 14/02/2025 12:31, Chris Hogg wrote:
On 14 Feb 2025 12:19:14 GMT, Tim Streater <tim@streater.me.uk> wrote:Except it doesn't work like that. There is inductance and capacitance
On 14 Feb 2025 at 10:44:43 GMT, "Chris Hogg" <me@privacy.net> wrote: >>>>>
But with DC, current is always at the maximum, so DI/DT is at its
maximum ...
If the current is at its maximum, i.e. not varying, then di/dt = 0.
If I is at its maximum, and the circuit is suddenly switched off, I
goes to zero very fast, and dI/dT is thus very high.
all over the place.
The motors are all AC, and lord knows there have to be massive clamp
diodes to take care of breaking any inductive circuits
They're three phase variable-voltage variable-frequency drives. There
will no doubt be snubber networks to control transients as the
MOSFETs/IGBTs turn on and off. The aim being to commutate the current
through the windings so there aren't any sharp edges (which would cause
EMI, amongst other undesirable effects).
Certainly I've never heard any noises on the radio attribuable to the drive.
Brian <noinv@lid.org> wrote:
Fuel economy is very good. Around town ( which is our normal use) 46 mpg.
On a clear run, nearer 50. Plus, ours came with a spare wheel.
For a tiny lightweight car that’s really rather abysmal. My wife’s diesel 4WD Yeti does 50-60 mpg.
Tim
Tim+ <timdownieuk@yahoo.co.youkay> wrote:
Brian <noinv@lid.org> wrote:Yes, so did our (2009 vintage) Citroen C5 Tourer (i.e. estate car).
Fuel economy is very good. Around town ( which is our normal use) 46 mpg. >>> On a clear run, nearer 50. Plus, ours came with a spare wheel.
For a tiny lightweight car that’s really rather abysmal. My wife’s diesel
4WD Yeti does 50-60 mpg.
Maybe nearer 50mpg most of the time but it always made me wonder why
people got tiny little cars because they were 'more economical'.
Indeed. Our petrol hybrid, which weighs nearly 1500kg, can get close 60 mi/gall on a benign long run.Most small diesels can get up to 60mpg.
(Harder to work out around town as it's not trivial to separate out the electric and petrol inputs).
nib
The rather egregious plugging of EVs by people like Prof. Hannah Fry
being a case in hand. There is no way she can't not know how shite they
are.
How about "hydrogen power" which is the new eco bollocks.
On 2025-02-15 09:28, Chris Green wrote:
Tim+ <timdownieuk@yahoo.co.youkay> wrote:
Brian <noinv@lid.org> wrote:Yes, so did our (2009 vintage) Citroen C5 Tourer (i.e. estate car).
Fuel economy is very good. Around town ( which is our normal use) 46 mpg. >>> On a clear run, nearer 50. Plus, ours came with a spare wheel.
For a tiny lightweight car that’s really rather abysmal. My wife’s diesel
4WD Yeti does 50-60 mpg.
Maybe nearer 50mpg most of the time but it always made me wonder why
people got tiny little cars because they were 'more economical'.
They can be. My Smart (really tiny) did an overall average over 25000
miles of 55, and a diesel Panda (not much bigger) did 58 average over
50000 miles. Both total mileage divided by total fuel.
Jethro_uk <jethro_uk@hotmailbin.com> wrote:
The rather egregious plugging of EVs by people like Prof. Hannah Fry
being a case in hand. There is no way she can't not know how shite they
are.
Weird. Have you owned or driven one?
After 50 years of driving conventional cars it’s only take one EV to convince me that I wouldn’t want to go back to an ICE vehicle as a daily driver ever again.
Jethro_uk <jethro_uk@hotmailbin.com> wrote:
The rather egregious plugging of EVs by people like Prof. Hannah Fry
being a case in hand. There is no way she can't not know how shite they
are.
Weird. Have you owned or driven one?
After 50 years of driving conventional cars it’s only take one EV to convince me that I wouldn’t want to go back to an ICE vehicle as a daily driver ever again.
How about "hydrogen power" which is the new eco bollocks.
It’s largely oil/gas company bollocks being promoted to preserve their control and profits.
Tim
It isn’t that rare just not in cars, most commuter trains in Southern England and a few on Merseyside have used DC with similar voltages for decades and before them Trams and Trolleybuses.
While the mechanical equipment designed for traction control would be too big to fit into an EV there were auxiliary circuits for heating and lights that used smaller switches.
Fortunately in recent decades the older mechanical equipment has been replaced by solid state circuitry a process that has been taking place all over the world and developing all the time, hence now EV’s have come along it has been relatively easy to source solid state circuitry designs that
are small enough for EV’s.
Jeff Layman <Jeff@invalid.invalid> wrote:
I'd known about the high voltage involved, but one thing I'd never
thought about (because high-voltage DC was rare before EVs) is the issue
of any arc forming. These are more difficult to extinguish than AC arcs,
so I wondered if anybody knew if any special precautions are taken with
EV circuitry to deal with DC arcs if they form. If so, what might they be? >>
It isn’t that rare just not in cars, most commuter trains in Southern England and a few on Merseyside have used DC with similar voltages for decades and before them Trams and Trolleybuses.
On 15/02/2025 08:44, Marland wrote:
Jeff Layman <Jeff@invalid.invalid> wrote:
I'd known about the high voltage involved, but one thing I'd never
thought about (because high-voltage DC was rare before EVs) is the issue >>> of any arc forming. These are more difficult to extinguish than AC arcs, >>> so I wondered if anybody knew if any special precautions are taken with
EV circuitry to deal with DC arcs if they form. If so, what might
they be?
It isn’t that rare just not in cars, most commuter trains in Southern
England and a few on Merseyside have used DC with similar voltages for >> decades and before them Trams and Trolleybuses.
Indeed, but those aren't "consumer" vehicles, and all it would require
to stop the arc is to cut the power supply which is fairly
straightforward with an external source. That wouldn't be so easy with
the power coming from batteries inside the vehicle.
Brian <noinv@lid.org> wrote:
Jeff Gaines <jgnewsid@outlook.com> wrote:
Hallelujah for the IC engine. I am considering a new car, small enough to >>> fit my 1980's garage. Any suggestions, IC only and about Kia Picanto size, >>> welcome!
We bought a Toyota Aygo as a second car just over 3 years ago, it serves as >> Senior Management’s Car and we tow it ( on a trailer) behind our motorhome >> - it is one of the lightest cars in its class.
We are very pleased with it. It came with a 3 year warranty but, if you
have it serviced by Toyota, they extend it every year up to 10 years.
The Aygo / Peugeot 107 / Citroen C1 (all the same car) has a solid
reputation for reliability too. The semi-auto gearbox is annoying though - better to go for the manual.
On 15/02/2025 10:18, Tim+ wrote:
Jethro_uk <jethro_uk@hotmailbin.com> wrote:
The rather egregious plugging of EVs by people like Prof. Hannah Fry
being a case in hand. There is no way she can't not know how shite they
are.
Weird. Have you owned or driven one?
After 50 years of driving conventional cars its only take one EV to convince me that I wouldnt want to go back to an ICE vehicle as a daily driver ever again.
Well the issue is what your 'daily drive' is.
A BEV would get me to the supermarket and back just fine, but I couldn't afford to run it and an ICE car as well, which I would need for longer
trips,
Marland <gemehabal@btinternet.co.uk> wrote:
It isn’t that rare just not in cars, most commuter trains in Southern
England and a few on Merseyside have used DC with similar voltages for
decades and before them Trams and Trolleybuses.
One project I'm hoping somebody does is to retrofit an EV battery + power system to an old electric train. If you start with an 800V battery then
it's more or less a drop in to a 750V EMU. You could optionally use the inverter to power the DC motors if the original traction controls were unserviceable. Sounds like a fun project for somebody in the position to do it.
Theo <theom+news@chiark.greenend.org.uk> wrote:
Marland <gemehabal@btinternet.co.uk> wrote:
It isn’t that rare just not in cars, most commuter trains in Southern
England and a few on Merseyside have used DC with similar voltages for >> decades and before them Trams and Trolleybuses.
One project I'm hoping somebody does is to retrofit an EV battery + power system to an old electric train. If you start with an 800V battery then it's more or less a drop in to a 750V EMU. You could optionally use the inverter to power the DC motors if the original traction controls were unserviceable. Sounds like a fun project for somebody in the position to do
it.
Do you mean actually equipment from an EV car or the concept of putting batteries into a former DC supplied electric train with equipment rated to
do the job?
If the latter then work has been going on for sometime with a company who purchased a lot of former
District line vehicles from the London Underground called Vivarail.
Like lot of these things the task took longer than anticipated and the company went into administration. However gWr purchased the remains and continued the project and is testing on the
Greenford branch in London.
Marland <gemehabal@btinternet.co.uk> wrote:
Theo <theom+news@chiark.greenend.org.uk> wrote:
Marland <gemehabal@btinternet.co.uk> wrote:
It isn’t that rare just not in cars, most commuter trains in Southern >>>> England and a few on Merseyside have used DC with similar voltages for >>>> decades and before them Trams and Trolleybuses.
One project I'm hoping somebody does is to retrofit an EV battery + power >>> system to an old electric train. If you start with an 800V battery then >>> it's more or less a drop in to a 750V EMU. You could optionally use the >>> inverter to power the DC motors if the original traction controls were
unserviceable. Sounds like a fun project for somebody in the position to do
it.
Do you mean actually equipment from an EV car or the concept of putting
batteries into a former DC supplied electric train with equipment rated to >> do the job?
Put a used EV battery in an old SR EMU, drive it on electric with no third rail, something no EMU has done in preservation. I think the guard's compartment in a lot of them would be enough to fit an EV battery, if the ~200kg weight is something they can take (~3 pax, so probably).
If the latter then work has been going on for sometime with a company who
purchased a lot of former
District line vehicles from the London Underground called Vivarail.
Like lot of these things the task took longer than anticipated and the
company went into administration. However gWr purchased the remains and
continued the project and is testing on the
Greenford branch in London.
That's way above the budget of the average heritage railway.
Theo
On 2025-02-15 12:53, Jeff Layman wrote:
On 15/02/2025 08:44, Marland wrote:
Jeff Layman <Jeff@invalid.invalid> wrote:
I'd known about the high voltage involved, but one thing I'd never
thought about (because high-voltage DC was rare before EVs) is the issue >>>> of any arc forming. These are more difficult to extinguish than AC arcs, >>>> so I wondered if anybody knew if any special precautions are taken with >>>> EV circuitry to deal with DC arcs if they form. If so, what might
they be?
It isn’t that rare just not in cars, most commuter trains in Southern
England and a few on Merseyside have used DC with similar voltages for >>> decades and before them Trams and Trolleybuses.
Indeed, but those aren't "consumer" vehicles, and all it would require
to stop the arc is to cut the power supply which is fairly
straightforward with an external source. That wouldn't be so easy with
the power coming from batteries inside the vehicle.
Here is an interesting summary of the requirements for an EV contactor:
https://www.durakool.com/information/technology/hvdc-contactors-failure-modes/
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