Bicycle Generator (3)

Visitors try-out a Mark II bicycle generator made by staff of the Electronics Department at the University of Essex during a Science Week event in March 2007, Hollytrees Museum, Colchester, UK.
An exercise bike uses a belt drive to a 12V DC permanent magnet motor, which works equally well as a generator. A 300W 12V DC to 240V AC inverter powers 40 watts of compact flourescent lamps, 120 watts of filament lamps and a portable TV. Running all of these at the same time is quite hard work!

Category:

Entertainment

Tags:

• bicycle
• generator
• science
• energy
• power
• university
• essex

[rodrigomaluf]

i have this bike , what kind motor can i use ?

[james9149]

It's a permanent magnet 300W 12 V DC motor, toothed-belt drive. Choose ratio to get 1500 rpm with 60-120 rpm on the bike pedals. Because it's a PM motor, it works equally well as a generator.

Tim.

[freshnelly]

Great vid! I'm from Essex too Cheers! I am planning a compact ped gen. for a boat, but worried about ratio vs friction. Any thoughts?

[james9149]

Frictional loss in our generator (mainly brushes) is about 12 watts at 1500 rpm when its output is 12 V. Don't know what's lost in the chain/toothed-belt drive. You need to make the overall drive train ratio such that pedal rate is comfortable for the 'rider', say 60-120 rpm. Hope this is useful! Tim.

[5horsepower]

i see what your saying about load settings and i wanted to say that i stuck a dc moter on my bike witch was on a stand and i spun the peddles and put the moter on the wheels and got 62 volts how many watts it that

[james9149]

Apart from frictional losses, no power is produced unless you also draw some current (try loading with light bulbs). Then power = V x current. Note that a dc motor with a field winding won't actually work well, if at all, as a generator. You need a permanent magnet type, which is what the bikes in the videos use; that works fine. Once it's producing useful power pedalling gets much harder!

[pixar5]

which dc motor would be good for this as i wired up a alternator and got no power at all very dissapointed hope you have the answer for me

[flufferman1]

i'm sorry wilfred but he lied, you will never be famous with a name like that...

[mattehv]

go for it wilfred

[Isochest]

I like it: Turn that excess lard off one's backside into electrical power. Could it motivate the Couch Potatoes who watch daytime TV to get off their big bottoms? But then again, getting up is what one does to get a microwaveable burger in a bun isn't it?

[d5gdf56gdfg]

If i get a bicycle generator where can i get a slave child to power it? I'm trying to be more eco-friendly here people!

[theRising5un]

I did the same thing, I used a rather expensive PM dc motor. I have a similar bike.

I use it to charge a 12v deep cycle battery then I watch TV from it. I have a 32" TV that is only 70W, amazing eh?

My solar panels do most of the work however.

Cheers.

[SSparks555]

I used an old 10 speed bicycle wich allows me to adjust to ratio to whatever is comfortable for me, also considering the load.