The secret genius of modern life: Prof. Hanna Fry; Episode 4 Electric Car.
An absolutely fascinating programme. Repeat still available on BBC2
8th Dec. 02.40; set your recorders, or alternatively, watch it on BBC iPlayer
Yes, fascinating program but surely they could have found a bird with bigger t*ts to host it?
It could have been trimmed to 20 minutes really.
The lightyear thing was interesting. Noy sure how "clever electronics" can get more power out solar cells that aren't facing the right way.
They also managed to miss the iceberg that is the secret future of electric cars. An omission so glaring it must have been politically influenced.
What *is* the secret future of electric cars? That they will always be more expensive, have a smaller range and take vastly longer to recharge than a similar petrol/diesel car? Or am I being pessimistic?
I'm surprised you are happy for any 'bird' to host a programme about cars. Surely Clarkson has to be the man for the job (in your eyes).
I am wondering: if BMW move production of the Mini to China, will they be able to insist on use of slave labour to keep the cost down?
I have just watched this.
I was interested in the bit about the single speed gearbox. I assumed electric vehicles (except maybe conversions) had no gearbox as such. However, from what I remember about trams, is it not possible to vary the tappings on the motor to act as a virtual gearbox. Can this be done, or indeed is it done? Also, for trains I believe that three phase AC traction is far more efficient than DC. Is this a technology suited to cars?
what vhe meant was a chick with big chebs
If you look at other electronic equipment (particularly phones), at least so far as range is concerned I would say you are. There must be some variation of Moore's Law applicable to batteries.
they should have no future like BSB Betamax wrong choice
When another emerging tech collides with them at the same time the energy and cost of living crisis become endemic. Although we wont' all need to put towels around our heads, if you wanted a really obscure hint.
In message snipped-for-privacy@4ax.com, Scott snipped-for-privacy@gefion.myzen.co.uk> writes
As there is only one overhead pickup (with the rails acting as Neutral), I thought that trains were single phase AC.
Adrian
Single phase 25kV AC current collection, except for the ones that use DC third rail or overhead wires. Multi-phase variable frequency/voltage AC traction motors, typically supplied from an inverter powered from a DC bus which is supplied from transformed and rectified AC.
Most EVs use AC synchronous or induction motors, which are driven by AC from an inverter.
Theo
I think it was about the electronics compensating for cells that were facing the wrong way having a lower output voltage than the ones that were, so each cell could contribute its maximum, without the higher output ones being dragged down by the lower.
What is that?
I'm no engineer (obviously) but from general reading I thought it was massively more complicated than that with a 'traction package' rectifying to DC then creating three phase variable frequency AC for the motors.
Someone will know ...
The motor speed is generally much higher than the speed required to drive the wheels, so a single speed reduction gear is needed.
It's simply not necessary, as the electronics can provide continuously variable control of the motor.
Lots of EVs use AC motors. 3-phase inverters are widely used in industry for variable speed drives, so it takes little effort to apply similar systems to cars. The motors also work well as generators, allowing energy recovery on "braking".
Some EVs use DC motors - but they still need electronic control.
Electric cars - Clarkson how very dare you, if it is not a twenty litre V-18 Clarkson is not interested (deliberate hyperbole).
I just sold my electric scooter yesterday.....looking for a mid 60's Honda now
The daft this is, the Porsche is one of the very few EVs that does in fact have a two speed box. Not a good example to use!
That is indeed the case.
Why would you want to in an EV? I suspect modern motor controllers have rendered such systems redundant.
EV motors are running off a AC current already. No idea how many phases are involved.
Tim
Oo, secret future. Please do share your inside knowledge.
Something they could have mentioned is the major part they may play in the future to help balance the grid and deal with renewable energy intermittency.
Tim
Of course. Its more green propaganda. The issues with net zero/heat pumps/electric cars/ renewable energy are all so glaring that no one dare even mention them. The Western Titanic is full ahead steaming for the Iceberg of utter impracticality, Need fresh deckchair sir?
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