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# How can I generate electricity from a spinning wheel? Answered

How can I turn the spinning of a small wheel/gear into electricity and then subsequently charge a battery with it??

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I want to generate energy from rotating trolley wheels. I have thought of dynamos but I no one can push their bags that fast. Basically my question is, "How can I charge gadgets from slow wheel rotation?"

Nice topic i just read all answers some peoples have given a very suitable and fine answer but anyone can explain it one by one easily

Part of the problem with explaining it is that we don't really know for certain what the OP is after. Most have assumed that he wants to generate a small amount of electricity similar to a bicycle - hence, the dynamo suggestion.

Whatever the spinning gear is going to do, it is the source of the power for some form of generator. A generator is an armature of one or more coils passing by magnets which cause electricity to be induced into the armature as the coils of wire on the armature cross the magnetic flux lines of the magnetic field around the magnet. The electricity is then harvested from the armature and applied to the load, whatever it is.

The field required can also be set up by coils of wire with a current flowing, called field coils, in place of magnets. The armature is usually rotated by the power source past the field coils or magnets, but it may be done the other way by rotating the field coils rather than the armature coils. The number of coils in each (the armature and the field coils) determines the frequency of the output along with the speed of motion. The number of wires in the coils and their resistance determines the amount of electricity is going to be developed in coil for harvesting. So the configuration and spacing of the coils is important to the efficiency of the resulting generator. The number of wires and current flowing in the field coils or the quality of the magnets used also affects the generator's efficiency.

Once we have assembled the generating equipment, the output from the generator can be determined. If the induced current is taken directly from the coils and fed directly to a wire somehow, the output will be a/c at some unknown frequency. To assure what this frequency will be, we will have had to design the generating system to be turned at a specific speed based on the positioning of the coils in the armature and the field coils or magnets positioning and strength.

Various means of causing the induced currents to be harvested are used to produce a/c current or dc current. An a/c current has a net dc voltage of zero as the voltage increases from minimum to maximum and back each revolution. In a normal dc generator, aka, dynamo, the current is pulled from the coils in the armature through a brush system that is positioned so that the positive voltage is applied to the wire output each time that the brush crosses the armature pad for the coil with the induced voltage available. So each revolution, the output wires (+ and -) are switched from coil to coil at just the right times so that the output appears to be a single positive voltage (with a small ripple). Calling this a dc generator = dynamo does not mean that other configurations of a generator cannot be devised to be dc generators - just that this is what most people are talking about when they refer to a generator, that is, a dc generator or dynamo configured as an automotive generator or a magneto.

In an alternator, the outputs of the coils are connected to the output line after being intercepted by a diode rectifier circuit which allows current to pass in one direction thus performing the function of the brushes. The arrangement of the coils on the alternator is reversed, so that the armature coils are not turning and the field coils are spinning and although they use a brush system (slip rings), the low current flowing in them does not cause them to wear out as brushes at high currents are prone to do.

So you can see from my answer that an answer that is simple and complete is probably not possible. The simplest means of producing electricity from a spinning wheel is like the kids bicycle dynamos of years past. Search for dynamo, generator, alternator and motor. Compare what you see and understand how they operate. Then you can figure out how to make a generator from a motor, how you can harvest back emf to help trickle charge batteries (the back emf is lost in some motor designs), etc.

I think that what the OP was looking for was a means to produce an output that would sustain the spinning wheel and output sufficient power to power a house, for example. If so, what he is asking for is a perpetual motion machine that produces great energy from little input. That ain't likely to happen.

I have done just that on a large scale , I have created a wheel generator that only captures kinetic energy when vehicle system has a velocity over 30mph or 50kph. 1/2mv2 = for 10,000lb suv at 30mph = 44ft/sec or 13.3 m/sec for the us system

this means 5,000 pounds x 44ft/sec x 44ft/sec = 5,280,000 poundals ft seconds and multiply that by 0.0421 to convert to watts is 497 kw

but at highway speeds of 60 mph this number for the 10000lb SUV 38,720,000 poundal ft x 0.0421 = 1,6 MW of stored kinetic energy.

So at highway speeds and multiple 12vdc alternator with built in IVR's internal voltage regulators. I have been able to capture 28Kw the extra rolling drag is 28,000 / 1,600,000 watts 1.7% extra drag so if it took 20Kw vdc to power electric vehicle. it would not be linear drag it would be 28,000watts - (20,000wtsx 1.7%) = net gain of 27, 660 watts in kinetic energy harvest . now at lower velocities it is less efficient at the 30 mph speed the percentage of extra drag 28,000 watts/ 497,000 watts = 5.6% drag from wheel generator 20,000 - (20,000 x 5.6%) = 1,120 wawatts needed

we have powered mobile trailer refrigeration doing this. see http://4dde.com

That energy is produced by the car's engine moving it along the road.
So it can produce that electricity for you it has to produce more power from the engine. None of the conversion is 100% efficient so the electricity you produce actually causes your costs to go up.
If you don't agree think what would happen if instead you drove a second alternator beside the original one. That would take more power from the engine to drive it and would add to your running costs but it would still be more efficient than the system you have devised, ingenious as it is.

What you say is correct except that the separated generator provides an easily transferable source of energy without a modification to the engine of the towing vehicle. So he was able to produce enough power to operate a refrigeration system without modifying the vehicle and that was usable on any trailer with the appropriate power connections and refrigeration unit.

That is a good idea.

However, it is not producing energy from nothing - it is transferring energy from the vehicle's engine to the refrigeration system using a relatively inefficient method. Rolling a wheel on the ground cannot be the best way to generate electricity and is fraught with potential problems.

However, the OP is asking how energy can be produced from a spinning wheel - there are those who claim that by starting a wheel to spin (essentially a small flywheel) and using the output to turn an alternator to create a/c power, they can operate the electric lights and appliances in a home - consistently and non-stop without connecting to any outside power once the apparatus is running.

That is not possible. The example I saw was a small motor (about 1/3 hp) connected to the flywheel at approximately 1:1 (1700 rpm or 3600 rpm most probably). The flywheel shaft was connected also 1:1 to an alternator to produce the electricity. The output of the alternator was presumably transferred to the starting motor after it was running to keep it running so that as the load was applied to the output, the transfer of energy to the load would be supplied by the rotation of the wheel, which would slow the wheel, but the starting motor would maintain its speed at a constant.

In addition, the same output shaft of the flywheel has a 1:1 connection to a secondary flywheel which is significantly smaller. This secondary flywheel could be there to help stabilize the system quickly if a load was applied. But just a rudimentary look at what is/could be happening shows that the system would not be able to run for very long without a battery or something to prolong its operating time. However, each of the flywheels include a loss due to drags and will slowly wind down to a stop, the starter motor's efficiency is not 100%, so it would be a cost to the system of more than it supplies to the flywheel to maintain its speed. The secondary flywheel will mitigate that to an extent, but it too has losses due to drag and its input is from the main shaft and will gradually slow down. So if the system were put in place and started, it would take a short time, but it would wind down. And the speed by which it wound down would be so fast that it would be unable to maintain the a/c voltage within tolerance within a short time and would slow to a crawl as though a brake had been applied.

The only way that this could be prolonged is with the use of batteries, but they too would run down unless an adequate source of outside energy is made available. All that has to be done to prove this is to make a reasonable estimation of the power required to operate each portion of the system: plus for output and minus for input. If the calculations are done properly and the energy of the flywheel appropriately assessed, it will be obvious that the system is not operational - it will have a nominal net negative. If the system is going to work for even a short time, the net (after the spinning wheel is fully up-to-speed) will only be positive for a short time - too short to maintain the speed of the alternator for very long at the appropriate output levels of voltage and current required for its own operation, let alone supplying a house with electric service.

Granted that the use of LEDs and very efficient electric motors will help, but not enough to make it viable. Sorry.

Maybe I am already too old but in my days we had so called Dynamos on our push bikes, flip it on the wheel and your light went on while you ride....

I remember those - had to rotate the wheels so as to avoid a groove being worn into the tyre wall - variable light intensity depending in your speed - LOL

There is also hot air going up all the ducts.
Can I recapture any of that to make the dryers more efficient?

I have a few laundry mats
High extract machines dryers running all the time
Compressers that run
I'm hoping to put those constant wheel spinning to make the energy needed to power the machines to run

Does this sound feasible?

A dc motor can be used as a generator. You may need to regulate the output voltage to prevent overvolting the battery. This could be done with a regulator, or by controlling wheel speed

Someone recently told me a boy aged 13 is creating a something that is applied to a car to create electrical output to a car battery and other devices in your car.

Why ?

Cars already come with an alternator that does all of that

I would also like to know how to make a simple one... I figured i would get it to go by using magnets... And the spinning would generate electricity to power a minor electric using conveinece

i think he is asking for a step by step process on how to get it to create electricity... Im curious about it too and do not know about this subject

it depends on how large the battery is. but you point out in your question that the wheel/gear is "small," so, don't expect your battery to be charged very quickly unless that small wheel/gear is spinning like a mutha-effer...

Use a dymano. You can find good old ones at antiue shops.

hey its easy, hust you need is a long copper wire, simple wires, blub that glows, high powered magnets......and a piece of metal too

bing the copper wire on a piece of cuboidal or cylendrical metal piece, bind two ends if wire to a blub, take high powered magnet and move magnet around the solenoid (piece of metal binded with copper), you will see that blub is glowing,,,,,,,,,,,,,

You could get one of those hand crank chargers and hack it into something...

A dc motor can be used as a generator. You may need to regulate the output voltage to prevent overvolting the battery. This could be done with a regulator, or by controlling wheel speed.

Older cars had generators which can work. New cars have alternators which must be rectified from AC to DC. They also require voltage to the field coils before they will produce power.

i would like to now that if wheel diameter is 3.5 ft. and its rpm is 280. how much maximum electricity can be produced

That depends on how much power is put into it.

Consider the following analogy: you are bicycling along a flat road. Easy ride. The wheel is 28 inches diameter. The wheel turns at a constant speed. Now you start up a steep hill. The wheel is still 28 inches. You wish to maintain the same speed. Therefore you must work harder.

The power you draw from a generator is similar. If it is a small generator, with 1 tiny lightbulb as the load, it wont take much power in to keep your 3.5 ft wheel going 280RPM. But if you have a big generator, and want to light every bulb in the house, as well as the refrigerator, then you have to put a lot of work into keeping that 3.5ft wheel going 280rpm.

understanding your point i have a project in college. my project is to find out that if a train is running at a constant speed of 60kmph for 400 kms. its wheel diameter is 3.7 ft. and i want to generate electicity by a magnetic shaft to this wheel than how much electricity can i produce

so, the generator is directly linked?

a rewinding magnet on shaft of 19.5 inch diameter rotating at 239 rpm can produce how much watt electricity

if my train is running at 45 kmph for 400 kms constantly and we think to fix a magnetic box on both side of shaft of wheels and thus the traction will be send to generator which will produce electricity which will be store in a battery. what i want to know is how much watts of electricity can be generated.

understanding your point i have a project in college. my project is to find out that if a train is running at a constant speed of 60kmph for 400 kms. its wheel diameter is 3.7 ft. and i want to generate electicity by a magnetic shaft to this wheel than how much electricity can i produce

If that is a college project, you aren't telling us something. Any energy taken from the train wheels will slow down the train. The speed of the train doesn't matter at all. Any dynamo can be geared up or down. What matters is the mass of the train and how much you are willing to slow down the train to make electricty and how much extra horsepower the train engines have to spare if you wish to maintain the speed.

i have same thing. if my train is running at 45 kmph for 400 kms constantly and we think to fix a magnetic box on both side of shaft of wheels and thus the traction will be send to generator which will produce electricity which will be store in a battery. what i want to know is how much watts of electricity can be generated.

Hmm, you could hook the spiinning wheel onto an axle which turns a generator to create electricity. Thats kinda how the National Grid in the UK works.

This instructable does a very good job of showing you how to build your own generator. In this case they used it as a wind generator, but you can use any means of spinning it to generate power. The number of coils you use and how you connect them together will determine the amount of power it will generate and what kind.

There are allot of things to consider when designing a generator.
• What will turn the generator
• what will the average RPMs be
• how much power does it need to create
• do the power requirements force the generator's size to be to big for the means of turning the generator to work
Its much easier to pull a working alternator out of a car and use it to generate power and charge a battery. Pretty much any induction motor you can find will do the trick if you can spin it fast enough for it to output the power you need. If that motor is able to generate the power you need.

Stick magnets to the wheel so that they pass over one or more coils of wire.