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Offline hardball

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Electric car
« on: 29/03/2006 04:01:52 »
I am by no means an engineer, so this might be a trivial question, but would it be possible to build a practical car that was driven by an electric motor turning the front wheels, while the rear wheels spun a generator that would recharge the battery?


 

Offline neilep

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Re: Electric car
« Reply #1 on: 29/03/2006 04:12:05 »
Hi Brian,

welcome to the site.

Hybrids exist as practical cars..Toyota and Honda already have had these vehicles on the market for quite some time.

As to electric only cars, if there isn't one already I am sure there will be soon....*thinks for a sec*....I think there is y'know !....

..lets wait and see what the experts say.

...or do you mean an electric car that YOU could build yourself ?...like a kitcar for instance ?
« Last Edit: 29/03/2006 04:12:50 by neilep »
 

Offline ukmicky

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Re: Electric car
« Reply #2 on: 29/03/2006 04:41:40 »
I'm also not an expert but a generator and an electric motor are basically the same thing, spin an electric motor by hand and it will produce a current. I believe they both work the same way, just the other way round

If your thinking can i produce free energy by having the rear wheel generator charging a battery while the same battery is at the same time powering  a spinning a motor on the front wheels then no.
They will both work together at the same time but the generator will create a  resistance as it creates a current making the rear wheels harder to turn and so the front wheels motor will have to work harder and drain more energy to overcome this extra resistance. The battery will go flat sooner or later. you would also be losing energy through friction, heat which cant be replaced through the generator on the back wheels.

Your best option would be to have one motor which powers the car on the flats but when you go down a hill it is turned into a generator charging the battery.

Where's Daveshorts  when you need him, probably tucked up in bed:)which is where i'm going now . Night Night:)

Michael
 

Offline daveshorts

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Re: Electric car
« Reply #3 on: 29/03/2006 10:59:34 »
Yeah what you are suggesting is a perpetual motion machine, so very unlikely to work.

 Energy is conserved so as michael says if you take electrical energy out of a generator you have to put extra mechanical energy in. In fact because none of the energy conversions will be perfect energy will get wasted, so you will enevitably end up with a worse miles per kilowatt than you started with.

Regenerative braking (using the motor as a generator when you want to brake) is however a good idea as you are storing energy that would otherwise just heat up brake pads.
 

Offline hardball

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Re: Electric car
« Reply #4 on: 30/03/2006 02:51:28 »
That makes sense. Thank you. BY the way, I love listening to your podcast.
 

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Re: Electric car
« Reply #4 on: 30/03/2006 02:51:28 »

 

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