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Mechanical to Electrical Energy Project - Urgent help needed!

  1. Apr 6, 2012 #1

    My friends and I are working on a "mechanical to electrical energy" project, and we're facing a huge problem with the basic design of our system.
    Basically, we wanted to make use of a system where a person would 'step on' a pedal or a tile, whatever you may want to call it, which would be connected to a series of pulleys, generators, and a circuit, which would, as a result, store the generated energy. The idea is to connect all the fore mentioned components in such a way, that when some force is applied to the pedal, it would make a pulley move, which would, in turn, make the generator's rotor move, enabling us to store the generated energy.

    This is how we want it to work:
    Before: http://tinypic.com/r/2mcvmft/5
    After: http://tinypic.com/r/348frmd/5

    As you can see, we have used magnets, and their ability to repel, to make the pulley move/turn. However, there is a major flaw in this idea. Although the magnets we are using are the strongest available magnets, they just do not move the pulley. The pulley and generator are connected, tightly, through a belt. Since the 'tightness' adds more weight to the pulley, it does not allow the pulley to be moved by the magnetic repulsion.

    I need some urgent help. I want to keep the basic structure of the project same, i.e. to make the pulley move continuously when some force is applied to the stepping platform, allowing energy to be generated continuously, and when the force is removed, the energy generation stops. If anyone can help me in this matter, the help would be greatly appreciated.

    PS: We do not want to use a DC Motor to make the pulley turn, since that would just make the system from a mech-elec to a elec-mech-elec.

    - Ahsan
  2. jcsd
  3. Apr 6, 2012 #2


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    Staff: Mentor

    It seems a much more efficient design would be the traditional one -- use a flywheel to help smooth the energy from stepping on the pedal, and use a directly connected generator (which is just a motor working backwards). Are there reasons that you are not using the traditional approach?
  4. Apr 10, 2012 #3
    First of all, thanks for replying.
    Since I am an Electrical Engineering student, with little knowledge about gear systems and the apparent use of a flywheel. Our idea is to somehow make the pulley revolve using any mechanism. Can you, please, tell me how the flywheel works? Moreover, can you explain it using diagrams? Because I have been trying to search for the mechanism of a flywheel, but I haven't been able to find anything that would be of any help to me.

    The thing is, our idea (to make the pulley revolve using magnetic repulsion) was unique, and apparently, (or so we thought) effective. It wasn't. We wanted to make a system, which would be 'buried' under the ground and only a small inclined tile or an inclined surface would be ON the ground. Kind of like this: __________,/ ,___________ (where the / represents the inclined surface which will be used to 'step on'.)
    An entire system would be connected to the inclined surface in such a way that when someone or something applies a force on it, it will move down, and get aligned with the ground resulting in the system generating power, somehow. We want the pulley (or whatever gear we use to this inclined surfact) to keep on revolving when someone steps on the inclined surface, and when the force is removed, or whoever's standing on the surface gets off, the system stops producing electricity. Sounds simple, no?
    Well, some students in my classes have made windmills, some have made power-generating bicycles. But all that stuff is easy and has loads of material on the internet. We wanted to make something different, and came up with this idea. But without proper assistance, I do not think we can carry on with the little knowledge we have of mechanical systems.
  5. Apr 10, 2012 #4
    My advice: Read, read read. If you want to create something novel, you need to learn about the various aspects of physics behind the design. Short of designing the thing ourselves, you probably wont get much out of us that you couldn't get by looking up these ideas yoruself...

    --Read up on flywheels and why they smooth out input from mechanical systems (Car transmissions use this)
    --Read up on generators (like alternators)
    --Read up on gearing so you understand proper gear train ratios and how much reduction is too much (and how too small a reduction is non-beneficial)

    Magnets are nice and all, but they just don't beat your good old mechanical pulleys or gears for energy transmission.
  6. Apr 10, 2012 #5


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    Staff: Mentor

    Look at the picture below. It is a picture of a foot-powered grinding wheel. The wheel serves as the "flywheel", smoothing out the impulses from a foot pushing down on the "treadle" pedal (this particular wheel has two treadles, but you can also do this with one treadle). You would adapt the concept to your preferred geometry, and connect a generator to the flywheel to do the mechanical-to-electrical conversion.


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