I have a question that puzzles me for quite some time. We have 4 wheels on a car that turns when you drive. Will it be possible that we can have alternators in all the wheel shafts thus having 4 sources of chargers ?. Thus we can have a self powering car with battery.!!!
This has got to be a troll. If you know the word 'perpertual' you are probably already conversant with the issue itself? Someone who wrote the question without using that term would probably be asking an honest question.
This was not a troll. I have searched the net and went to the library to find about the energy loss on DC motors but I could not find an answer. How much energy was needed to run a car and how much of it could be generated by the movements of the car and maybe some help from a solar charger is a subject that I would like to learn more about. I came across this newsgroup and thought a knowledgeable person could help me for my curiosity. I used the word perpetual just to draw attention to my post. Thanks for the web site though, I will check it out.
The energy to drive a car at constant speed on flat and level ground is dependant on the various forces, frictional losses, road loads, aerodynamic drag, etc...
To power a car as you suggest would not work....at least not completely. The alternators are only so efficient and the rest would be lost somewhere as heat, plus you would need some external source of energy to get it started in the first place.
Do a search for the electric vehcle discussion list and you should get more information than you could imagine....
Nope. The wheel mounted generators will produce a torque as they put out electrical power that acts against the direction of wheel rotation. Just like dragging your brakes. You now have to put more power into the propulsion system to overcome this. Its not quite as bad as dragging brakes, since part of the energy consumed will be returned to the battery. But you only break even if the generators are perfect, i.e.. zero loss.
There is one application of this idea that I've seen. That is, the construction of a hybrid car by adding a motor-generator electric drive to the two wheels not driven by the internal combustion engine. This system was probably somewhat less efficient than a hybrid with the motor-generator coupled to the IC engine (as is done now), because the 'charging power' is coupled from one axle to the other through tire rolling resistance. But it did allow the creation of a hybrid without having to 'break into' the conventional drive train. And it created a part time all-wheel drive system.
Oh, I don't know. I suppose it could be made to work, But the real problem as I see it is getting rid of the surplus electricity which you may not need.
One design I saw recently used the pointed aerial to squirt a charge into the air and that way dissipate the excess electrical energy. It may sound odd but it's better than a design I saw a few month ago which has a fast-turning spool mounted on the rear of the car and letting out a long wire which was plugged in at the other end to the motorist's own house.
I think they had some leyden jars on the roof and stored the energy there.
Anyway, can I come back to an important topic which is troubling me quite a lot these days. Why doesn't my Nokia phone change the traffic lights in my favor as I approach these days? Have they changed the frequencies or the encoding scheme of the sub-ether signalling?
OK......since we seem to be seeking perpetual motion here, and I'm bored...let's play!
Real science only.....and real products, lets make a car that will never need to be plugged in, does not have any substantial emmisions (gassing of bearing lubes, outgassing of VOC's from fiberglass, but no burning of carbon based fuels).....if you have the money it can actually be done.
No Tesla coils, leydon jars, or vaporware......
permanent magnet motors
lightweight construction (fiberglass and carbon fiber, polycarbonate windows)
This can be done today with "off the shelf components" and give you a range of around 300 miles per charge (with about $30,000 worth of batteries) but you still have to plug it in.....
To get past the plug, you need to combine the lithium batts with something from these guys.....
-------------------- The energy to charge the batteries comes from the alternator and eventually the IC engine. If you put alternators on the wheels, then the charging energy would still come from the IC engine as the energy to the wheels would be that to provide normal propulsion plus the charging. That is, if you were driving at a constant speed, you would have, say 40KW to move the care and regenerate ,say, 10KW. That would require a net input from the engine of over 50KW. All you would have is a more complicated way to do what is happening now- with a single, belt driven alternator- with the possibility of getting some regenerative braking.
You definitely will not get a self powering car!
Added comment for Anedix:
What excess electrical energy? If you are not using it or storing it, you aren't producing it.