Exercise bike generator using a car alternator

[libertyORrevolution]

Seems like a lot of work for three light bulbs...you might just want to light a candle!

[vox1philippines]

this is my next next projects...... NICE ! is it need a bigger batery for the exiter? ......Thankz...

[PrestoWind]

Why don't you put a permanent magnet rotor inside the pma? You won't need to excite the field.

[tomgloria]

@PrestoWind that would work.

[oguretsagressive]

Beautiful rig! You really possess a skill. However, AA's are not a best way of energizing the excitation coil i think, especially if you are using alkaline cells. I've experienced a severe voltage drop while experimenting with my own device. 12V 70A*h battery was better. Would you mind to share some statistics? How much peak wattage did you get? What was the maximum speed of alternator's shaft?

[tomgloria]

@oguretsagressive you are right, the alkaline cells will cause a severe voltage drop. This is by design. When I bring it into a classroom, I want the students to immediately feel the draw by the lights. With a bigger battery to smooth it out, it works better, but the students don't feel the load. Peak wattage I've been able to achieve is ~15. I recall that at 80 rpm of the exercise bike we were in the 2000 rpm range of the alternator shaft. Thanks for your message.

[XsmashX1]

Wouldn't having a bank of batteries be ideal rather than wiring it to some light bulbs?

[tomgloria]

The two different types of light buls are used to demonstrate the difficultly of lighting incandescent light bulbs vs. CFLs of similar lumen (light generation capacity) rating

[XsmashX1]

Okay, I only read the heading, not the description. But you were obviously comparing the two.

Do you have a battery bank too? I'm thinking of building one myself but I'm inexperienced. Doesn't look too complicated. I hope it isn't. I'm ganna look for some plans online.

[NOCNOTCAUGHT]

Fantastic job!!

[jaydelanyack]

Are you a science teacher? :)

[pixar5]

thanks for your help i appritiate that information will give it a try and will let you know how i make out thank you

[pixar5]

hi great job doing this by lighting lightbulbs . i have a car alternator as well but 2 questions if you dont mind me asking the alt has 1 peg for the positive terminal of the batt but the underneath has 4 small pins 1 big one followeed by 3 small ones how would i wire it up to hook up the swithch to energise it ? the other question is does the alt need 12 volts in the batt to get it to work

[tomgloria]

From your description, what you need to do is complete the circuit for the alternator to sense that a battery is operational and is charging. So you need to attach the small bank of batteries' (12V total - 10 AA's is what I used) positive side to the positive of the alternator and to the big pin of the four smaller pins. You need to then connect the negative side of the bank of batteries to the ground or case of the alternator.

[tomgloria]

Set up a switch circuit from the big small pin to the field sensing pin, one of the 3 small pins, likely the middle of the 3. To get the alternator going, you need to first come up to speed then flip the switch to energize the field circuit.

Regarding the batteries, yes, you need to use 12 V, but it is better to use a small bank of batteries that are drained quickly, so you can see the flickering of the lights. You could use a big battery, but the lights would turn on without peddling!

[tomharrisonjr]

Totally cool!

Nice work on the switches, Isabelle! Patrick -- you deserve a spot on the Tour de France. Nicky -- one word: Oscar.

We would love to come over and check it out. And then we'll take you guys off the grid for an evening of well deserved rest -- we'll guarantee a steady 14 Watts and pizza of your choice.

Tom H and the gang

P.S. Our best use of exercise equipment for energy savings has been as a clothes rack (saves on use of the dryer :-). You win.

[jumperolson]

What a nifty gizmo! I know some Newton Middle School technical education science teachers that would like to see that, at a workshop this July. I will be in touch!

Cheers,

Eric