pedal power

[Dr]

it has been some time since I posted anything,but I was wondering if it would be possible to build a pedal powered energy system, using a homebuilt low speed alternator. I believe one would have to use a large flywheel to keep the load from bogging it down. would the wire in the copper coils be a large diameter or small? I would of course be using a battery storage system! any thoughts would be greatly appreciated

[Magluvin]

I ride electric bikes. I have 3, 1 is 600w and a 500w and a 750w.

From what I understand, we as humans on bikes can produce 100w. Something I read. Not so sure about that. I know guys that ride 30 miles at 35 mph on a long flat road. I might think that they are producing more than 100w, or to say consuming more than 100w of human energy.

You dont have to use an alternator. Automotive DC electric cooling fan motors are smaller and have permanent magnets so the output is DC without the use of diodes. They work very good as generators and are good for 20 to 25 amps of continuous currents at 12 to 14 v, if you are able to pedal it to those levels, of which can be between 250 to 350w output, depending on the load.


Lol, I had a thought once based on the Matrix movie, sort of, was to have people driven power plants, but it is like an exercise gym with all generative exercise equipment. Maybe the people get paid to work out, or maybe its free, as compared to the prices of a nice gym, free may be attractive.
But then the place has to be AC'd which would require quite a few consistent members producing just for that, along with lighting, music, equipment electronics, 'air freshening' , etc.

Then again, maybe it would only be enough for the gym to save some money on its electric bill.

Mags

[Dr]

Magluvin: thanks for the response,yes I agree that a human in good physical shape should be able to produce more than 100 watts of power, thats less than 1/7 th HP. I went out to the shop with a crazy idea and put together a quick setup of coil and magnets. My coil was a 100 turns of 22 ga. with a 1 sq. inch center hole . My magnets are 1/2 thick X1X1 neo. N42. I already had some 1/2 " MDF circles cutout so I made a quick mockup with axle and stator that would hold my coil!. My first test was I wanted to see how many leds I could light with the magnet passing over the coil the conventional way ( at 90 degrees or straight on) I hand cranked the rotor at 60 rpm and found I could barely light 1 led. and then I cut out a space on the opposite side of the rotor, so that the magnets are now cutting the same coil at a 45 degree angle, I also held the coil at a 45degree and cranked the rotor to the same 60 rpm, and I could now light 4 of the same size leds. I thought that I would be able to only light 2 leds since I was cutting  Twice as much copper with the same amount of flux. but to SQ. the output I was kind of surprisedCan someone else verify this, or am doing something wrong?

[Lakes]

http://www.youtube.com/results?search_query=Pedal+Power+bike&oq=Pedal+Power+bike&gs_l=youtube.3...29666.34889.0.36050.16.14.0.2.2.0.360.2273.3j8j2j1.14.0...0.0...1ac.1.11.youtube.SnvJ09zQvJU

http://www.youtube.com/watch?v=kVAZIDFMRXY

[Magluvin]

Magluvin: thanks for the response,yes I agree that a human in good physical shape should be able to produce more than 100 watts of power, thats less than 1/7 th HP. I went out to the shop with a crazy idea and put together a quick setup of coil and magnets. My coil was a 100 turns of 22 ga. with a 1 sq. inch center hole . My magnets are 1/2 thick X1X1 neo. N42. I already had some 1/2 " MDF circles cutout so I made a quick mockup with axle and stator that would hold my coil!. My first test was I wanted to see how many leds I could light with the magnet passing over the coil the conventional way ( at 90 degrees or straight on) I hand cranked the rotor at 60 rpm and found I could barely light 1 led. and then I cut out a space on the opposite side of the rotor, so that the magnets are now cutting the same coil at a 45 degree angle, I also held the coil at a 45degree and cranked the rotor to the same 60 rpm, and I could now light 4 of the same size leds. I thought that I would be able to only light 2 leds since I was cutting  Twice as much copper with the same amount of flux. but to SQ. the output I was kind of surprisedCan someone else verify this, or am doing something wrong?

Hey Doc 

If you are just looking to light leds, for the moment, try more turns on your coil. Also it is good to have the mags alternating NSNS and to space them so the mag centers, the N mags center is crossing one side of the coils windings and the S mags center is crossing the other side of the coil. This will double the number of windings being 'cut' by moving fields. 

1 magnet crossing the face of the coil, the fields will cut the approaching side of the coil first, causing current to flow in one direction in the coil, then as the magnet crosses the departure side of the coil, currents are reversed.  So as the mag passes the coil, you get 1 cycle of AC. By having more mags as I said above, you will get AC also but more and a continuous wave of AC. With the 1 mag as you have it, try to use a full wave rectifier to charge a cap, then see what voltages can be reached by storing each generative pass of the magnet. The you might be able to light the led using a current limiting resistor from the cap and get constant light from the led instead of blinking.

Is your coil air core?

Mags