Worked for 52 Years, Still Running: 1912 C-T 4WD Electric Truck
bringatrailer.com
bringatrailer.com
They expected to be a surprising and exotic sight, but one of the bellhops asked them if they knew Mrs X, who had been driving to the hotel for 5 or six decades until 2001 in her similar electric car.
The students are now fitting in Li-Ion batteries. There will be no power electronics, just a mechanical switch that can put coils of the 4 pole DC series wound motor either in parallel (high torque) or in series (high speed). The motor has 4.5HP and the car has a top speed of 35km/h.
Having worked with ME students in the past I can say with confidence you won't be using those adjectives to describe the project when they're done with that.
Rookie mistakes aside, what you do for grades has little overlap with what you do to get a good result. Every college engineering project has this problem. The things you'd do to deliver the best result possible with the resources you have are not the same things you'd do if you're optimizing for grades. You do dumb things run a simulation to prove you can and check the box when in reality you should just over-build it and spend the time on part of the project that's gonna require a few revisions to get right.
Of course you do. Why on earth would you think that's a bad thing?
My guess is that this is putting the coils in parallel, not the batteries.
According to that link, the applied voltage determines the speed and the applied current determines the torque. I don't know the exact configuration of the windings in these motors, but having the coils in series should be putting a higher voltage on the motor (higher resistance), and having the coils in parallel should have more current (lower resistance).
Pretty neat way to get a "2 speed" transmission. Of course, it's not going to be as good as the current generation of BLDC motors (variable speed is tricky with bang-bang control...), but for the time it's a pretty clever solution.
It's almost identical to how the two speed "transmission" works on 12 volt Power Wheels toy ride-on vehicles.
In those, there are two motors connected to the rear wheels; one for each wheel. Using a couple of switches on the "shifter", the motors can be connected to the battery in series (high speed) or parallel (low speed).
Also interesting is that by using two separate motors in that manner, you gain a form of "electromechanical" differential (not that it matters much, as the plastic wheels have insane amount of slippage on most surfaces).
See the patent: https://patents.google.com/patent/US4639646A/en?assignee=%22...
Could someone clarify?
If the two coils are in series, you'll have a total coil resistance of 12 ohms (13 ohms incl internal resistance), and will get 0.923A (12V/13ohm) through the motor, with a terminal voltage of 11.07V (12V x 12ohm/13ohm).
If the two coils are in parallel, you'll have a resistance of 3 ohms, and a current of 3A through the motor (12V/4ohm), and a terminal voltage of 9V (12V x 3ohm/4ohm). Lots more current, but lower terminal voltage.
Edit: formatting
There's a wonderful book "The Shock of the Old" about the meandering ways innovation takes.
Currently, $1 (retail price) of gasoline delivers more joules of energy than any of the competition. The rise of fracking has made nat gas a contender, but gasoline is still dominates.
Most comparisons to electric vehicles are actually a comparison of a car that runs on gas vs a car that runs on coal, guess which one wins?
Sources: https://www.eia.gov/energyexplained/index.cfm?page=electrici...
You can reduce the emissions by adding technology to process the combustion products to clean them up before emitting them, but you are limited by the fact that your cleanup technology has to be small enough and light weight enough to include with the car.
If you burn that same fuel remotely to make electricity, and use that electricity to power the car, now the pollution is being emitted at a fixed location.
We can pick that location to minimize the harm from the pollution that is emitted, and we can use far more effective cleanup technology at a fixed plant than we can on a vehicle.
I'm not entirely sure how accurate my knowledge is though, it's based on a few sort of tangential comments that connected some other data points I know, and not from any one source I can cite.
Also, the impression I got was this ignores things like leaking oil, which isn't measured by my state's emissions test. So I'm not trying to make claims about overall pollution effects between gas and electric.
At least for Europe, this is not true. Electricity source varies by country, but it's in general a mix of 30%-50% nuclear, the rest is thermal or renewable. For thermal power-plants, the large majority are natural gas. Renewable percentage varies wildly between countries, but breaching the 50% barrier on a given year is no longer newsworthy.
> Most comparisons to electric vehicles are actually a comparison of a car that runs on gas vs a car that runs on coal, guess which one wins?
Very true, but it depends on your energy provider to these actual numbers. For instance, if I were to buy an electric today and plug it in; 48% of it would be powered by coal, 12% wind, 1% hydro and solar, 7% nuclear, and 32% natural gas and oil (no idea on how much is NG vs oil). Efficiency in production of renewable resources and social pressure would bring this number down.
Or, if money were no object, an array of solar panels (and that price is dropping every year) could easily power my garage and all the things inside it. No coal, no emissions.
#1 Electricity delivers far more energy per dollar, especially off-peak. Local EV owners are complaining on social media that they're averaging five cents per mile in the below zero temps we've been having. Using offpeak energy and good weather, costs can drop below one cent a mile. At $3/gallon and 25 mpg, that would be 12 cents a mile in a typical gas vehicle.
#2 Coal is dying. Dropping natural gas and solar prices are killing it. Electric autos get cleaner as the grid does.
#3 Even if you got lots of energy per unit of gasoline, simply refining one gallon of gasoline uses enough power an electric car can travel >15 miles on the refining energy alone.
The $1 gasoline is poured into a horrendously complex, noisy, brittle, contrived piece of technological megadebt.
Electricity goes to one motor per wheel it needs to drive. In 1912 and in 2018.
As ugly as a gas engine is it does offer quick refueling, long range, and low cost. It's just more practical, especially with turn of the century technology.
Both 19th/20th and 20th/21st according to the sales numbers
I do fully expect we will have these problems licked before the next turn of the century.
There is typically a trade-off between maintenance and replacement. Piston engines require on-going maintenance, but can last a really long time. Electric motors require almost no maintenance but need to be rebuilt/replaced more often.
Electric motors, power electronics, and simple reduction gears can last 5-10 times longer.
One of the few times I felt "mind blown".
70k of the EV miles I've put on have been with 93.3% non-fossil fuel based sources[1]. If you're in the PNW EVs are a clear win both from fuel sources and the fact that it costs me $6/300mi at $0.07/kWh.
Looks like it went to the wrong thread when HN hiccuped.
https://en.wikipedia.org/wiki/Taxicabs_of_New_York_City#Late...
Also in early 1900s, a Baker Electric was part of the first White House fleet of cars. President William Howard Taft changed things up at the White House, converting the stables there to a garage and purchasing a four-car fleet on a $12,000 budget (equivalent to $326,844 in 2017).
https://en.wikipedia.org/wiki/Presidential_state_car_(United...
https://en.wikipedia.org/wiki/Baker_Motor_Vehicle#Special_Ba...
Modern steam engines do not require lubricants, are low emission and can use renewable energy sources.
https://www.google.com/search?q=ford+catapult+aircraft+carri...
You can get around that some by venting and filling water but that also becomes a system limit.
Meanwhile the downside to a huge ICE is fuel consumption.
So what's left is carbon in different presentations : wood, or coal, etc.
Thanks for the article
In the battery compartment, nine trays were used to hold a 500 pound, five-foot-long lead-acid battery pack that produced 10 volts.
I guess it is 10 volts per cell, not for the entire pack? With 9 cells in series that would give 90 V which sounds close enough.
Still confused. :)
https://archive.org/details/audelsnewelectri008004mbp
Chapter 162(!) at the end is short but entirely about electric trucks and tractors. The rest of the book is mostly electric locomotives and there is also a short section near the end on electric elevators.
Having a vehicle that's more than likely able to last 25+ years without any real maintenance at all* is extremely enticing. I wonder how this will affect future electric car values. And I wonder if we can curb our consumerism mentalities to actually let something like this happen.
Unfortunately, with the tech-minded companies producing these vehicles; I'm afraid of planned obsolescence.
People don't really appreciate that enough. It's mostly solid state electronics. The only major degrading part is the battery. Its currently not too cheap to replace, but it is highly recyclable. Fix the battery and the car is basically new. The drivetrain will last for a long while.
I'm sure they will be engineered to a certain life expectancy, but I'm interested to see how long they will end up lasting in modern automotive applications.
They operate in extreme conditions though, so that's certainly a factor.
Then there are the little things breaking everywhere. A light here (leds improve that), windshield wipers, maybe a broken cupholder. These are also not impacted by the drivetrain.
In general though, a car breaking down frequently, or one that constantly gives the owner trouble when they are trying to go somewhere (failing to start properly, etc) is much more problematic. They will end up in the dump. This is where I was aiming my comment at.
https://losangeles.craigslist.org/lac/cto/d/1912-t-electric-...
Also, people forget that the first cars were electric. Battery tech just wasn't there 100+ years ago and the combustion engine won out...
https://losangeles.craigslist.org/lac/cto/d/1912-t-electric-...
There were early (earlier than internal combustion) electric cars, but external combustion (steam) cars were even earlier (both prototype and practical vehicles.)
Sounds impressive, the covered wagon cab when it came out is interesting too.
> 85-volt, 10-amp General Electric motor
> They each produced 16 HP when new
85V 10A -> 850W of power provided to each motor16HP is just under 12000W, so the motors had an efficiency of 1404% ?
Motors are normally rated in continuous power, but I bet marketing materials would mention the peak power, since that's most relevant to the use case of getting up to speed.
Tangentally, I came across this film from Market Street in 1906. There's lots of different modes of transportation in use - horse-drawn carts, electric cars, gasoline cars, cable cars, electric trolleys, and pedestrians (who were amazingly casual about dodging between everything else that was moving - the accidental death toll was probably huge)
Probably less than you'd think.
Traffic now likes to forget that while the legal rules offer redundancy 99% of the time (if only one party follows the rules the other party should be able to take action to avoid a conflict if it is following the rules that apply to it) the legal rules do not supersede physics.
I walk to work every day. Morons on foot cut off morons on bikes who cut off morons in cars who cut off heavy trucks.
You only need to see a horse turned into taco meat once or twice to learn why you shouldn't rely on other traffic's ability to pick up the slack for your dumb decisions. People learn what to do and what not to pretty quickly when the stakes are higher than someone slamming on their brakes and honking at you.
Residents of southeast L.A. County rejoiced this year at
news that a battery recycling plant that had long emitted
lead, arsenic and other dangerous pollutants would be
closed.
http://www.latimes.com/local/lanow/la-me-exide-cleanup-story...When I worked as a stock boy at K-Mart in the 1990s I remember a whole corner of the loading dock was kept stacked with used and returned batteries, many of them leaking all over the place. I was just a kid and didn't know much, but I knew enough to not want to go anywhere near them. Thankfully only those working at the return counter and on the loading dock handled the batteries.
Now Edinburgh has them and spent god knows how many billions on it.
https://en.wikipedia.org/wiki/Milk_float
Very characteristic motor sound early in the morning.
And as you say towns are now putting trams back in - though places like Blackpool did keep theirs.
There's a major push to expand it throughout downtown/suburbs. It's definitely a cool factor still at this point, but plenty of people who wouldn't ride the bus are going out of their way to ride that.
As a local, I'm excited to see it expand. They've made public transportation sexy, efficient (100% electric), and convenient in a city where the average household has two cars and everyone drives themselves.