Bike Generator

Here is a look at the bicycle generator I built this summer to use in my physics classroom. The funding for this project was made possible by a grant from the Knowles Science Teaching Foundation.

Category:

Science & Technology

Tags:

• bike
• generator
• human
• power

[akdebbink]

Pixar 5, What size kole capacitor did you buy? The larger the capacitance, measured in Farads, the better job it does at smoothing out the voltage variation. Depending on the DC to AC inverter used you need to maintain a voltage between 10V and 15V, even under a load. I have never tried using an alternator as a generator, but I can't imagine that it would be much different than a permanent magnet scooter motor. A battery should do the trick, but you should be able to get it working without.

[akdebbink]

The capacitor helps smooth out the voltage coming from the generator (scooter motor). The inverter can handle a fairly wide range of input voltages, but the voltage from the generator can vary by 20% while pedaling because you can not maintain as constant of a rotational speed as you may think. The capacitor keeps the voltage variation around 10% while pedaling.  This makes it considerably easier to power without a battery to maintain the nearly constant voltage.

[francyh199]

what is the use of the ultracapacitor ?and could you make like a plan on how to connect the stuff? thanks ! amazing job

[akdebbink]

@francyh199 If you are planning on using a battery the capacitor is not needed.

[akdebbink]

If you are going to attach a multi-meter to measure the current going into battery while charging or leaving the battery while powering devices make sure you have a similar voltage on the capacitor (compared to the battery) before connecting the battery to your electronics board. If the capacitor is empty when you connect the battery you will get a large spark and a large current spike which will blow the 10amp fuse on your multi-meter. I have gone through 2 in the last week.

[akdebbink]

To connect the multimeter, connect the ground to the low voltage (black in video) wire of the generator / capacitor. Attach the voltage measurement connection to the high voltage wire (red in video) of the generator, capacitor and the positive terminal of the battery. And finally connect the current sensing connector on the meter to the negative terminal of the battery. This will allow you to measure the voltage on the battery and the current going into or out of the battery.

[pixar5]

just curious i picked up a kole capacitor and i get the same results 1 13 watt light bulb flashes off and on im using a perment magnet alternator which i can pedal up to 26 volts with no load hmm do i need to hook this up to a battery as well ? i thought it would smooth out and hold the voltage better or is a scooter motor stronger voltage then the alternator the alternator can produce even more power if i can pedal faster but i think theres enough voltage is it no amps coming out of the alt