O.T. electric cars - do they have gearboxes?

Apr 19, 2017 141 Replies
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Some of us were not willing to risk MMR, but paid for single vaccines to gain the protection - rather expensive at 3 vaccines per child, £136 per vaccine and 3 children, but we had our reasons.

At the time of the "scare" my wife (a nurse) worked directly with two different colleagues, both of whose children were developing normally, both children had the MMR, both suffered a fever and went floppy the evening of vaccination day. In both cases, the children took a week to recover and had regressed significantly. Both were later diagnosed as autistic.

Having such immediate experience of what some people were saying persuaded us not to take the risk.

Getting the single vaccinations was not easy, as not only were they expensive, but the government had apparently put a limit on how much could be imported, creating a national shortage.

SteveW

Ah! I now see the point being made by Andy. :-)

I like your definition, "SI = Somewhat Inconvenient"[1]. I've watched enough episodes of "QI" to know better by now. However, in my defence, I'm not habitually writing scientific papers where such precision of terminology is a vital part of not being deemed a bit of a D*****ad by one's peers so lack the experience required to remain up to date with the latest fads in SI unit terminology.

I'm now aware of the fact that Kelvins (or, more precisely, Kelvin)

*aren't* degrees. :-) [1] It occurred to me that the misunderstanding was more to do with semantics so I think a better definition of SI may be[2] "Semantically Inconvenient". [2] Please note the *correct* usage of "may be" in this case. I'm sick of the sight of "may be" when the *single* word "maybe" was intended (along with the less common but equally irritating use of "maybe" in place of the phrase "may be"). Apologies for this mini-rant but it *does* feel good to get that off my chest. :-)

There was an article some time ago saying that you can do better than that. Follow up the whole train with a closed circuit system containing LPG. The waste heat boils the LPG which drives an expander to produce more power. Extracting the energy cools the gas to a mixed vapour/liquid which can then be cooled a little further in a condenser to re-liquify it for re-circulation.

Steve W

Correct. You can have a difference of 10 degrees Centigrade, 10 degrees Celcius or 10 Kelvin and they are the same ... you cannot have 10 degrees Kelvin, it is just wrong! °C is a relative scale, a gradient, hence the degrees, whereas K is an absolute scale, a fundamental unit, hence no degrees.

Now, how about Rankine?

SteveW

How can it have a gradient when its scalar?

The bit of the equation is just where the constant for kelvin is zero.

The law of diminishing returns steps in. You cant get lower than ambient, and even if you could get back to ambient its still only around

70% from memory.

You need to have a hotter gas to start with.

It is quite true, though the actual method is somewhat more complicated. I was about to start writing a description, but it is covered rather well here:

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About the last UK stock to be built using this principle was the

1983 Tube Stock which was retired from service comparatively early in 1998. Older examples are still in daily use.

Chris

I claim originality for that. It certainly seemed more than a little inconvenient when the change came in, in the late 1960's IIRC.

I'd take that as the apology Tim :-)

About the same price as the BMW - surprised, thought it'd be a fair bit more.

They're quite expensive but a lot of spreadsheet what-ifs showed that buying it in a company was cheaper over 3 years than buying an equivalent 2-3 year old petrol or diesel (hisss ;-) ) car and running that privately for 3 years, this was allowing for all factors (including depreciation). I've been very pleased with it so far.

Although the article mentions pretty well all aspects of DC motor control as historically employed for railway locomotion, the use of a journalistic style over a technical authoring one resulted in a confusion of descriptive terms (eg currents instead of magnetic fields and the impression that the [armature] windings on the rotor were wound *around* the rotor shaft).

Although the author 'loses points' for the use of confusing terms, he does gain points for his comprehensive coverage of the difficulties, imposed by the limitations of the technology of the day, facing the designers in their attempts to recover the braking energy for use by other trains on the line.

OK, if you want a bit more reading, try these

Principles of Direct Current Electric Traction

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Electric Traction

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Chris

Thank you for those links, Chris.

I had a quick look at the linked pdfs and they look an interesting read so I've downloaded them for future reference. :-)

Yes,. When I started in the industry a colleague lent me Dover, which had much of what I needed to know at the time. I did get a photocopy of the entire volume, but somebody never returned it to me :-(

Chris

o quiet and amazing acceleration.

motor just run faster the faster you go? I was told by the owner the optim um speed for economy of battery usage is about 55mph.

What do you folks think about the company Adomani, which goes public tomorr ow, with the symbol ADOM? I think their technology sounds pretty cool and I ?ve been reading everything I can find about the company recently, leading up to the IPO and I?m pretty impressed already.

I?d really like to get into this one on the ground floor because I have a strong feeling, based on the research I?ve done, that this o ne is going to take off shortly out of the gate. So I?d be really i nterested in hearing what others have to say about it.

o quiet and amazing acceleration.

motor just run faster the faster you go? I was told by the owner the optim um speed for economy of battery usage is about 55mph.

What do you folks think about the company Adomani, which goes public tomorr ow, with the symbol ADOM? I think their technology sounds pretty cool and I ?ve been reading everything I can find about the company recently, leading up to the IPO and I?m pretty impressed already.

I?d really like to get into this one on the ground floor because I have a strong feeling, based on the research I?ve done, that this o ne is going to take off shortly out of the gate. So I?d be really i nterested in hearing what others have to say about it.

Haven't you heard? Stock spam stopped working in 2011

Is "Pump and dump" something to do with electric cars, then?

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