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This bike generator design is good for running low power devices such as:
- An iPOD through a 12V Car cigarette lighter adapter like this one.
- Cell phone chargers
- Portable DVD player
You can use off the shelf parts from local stores to make this 296 Watt pedal power bicycle generator or buy parts from Amazon.com
Through volunteer efforts, 24 of these pedal power bicycle generators were assembled and used for charging cell phones at a 3 day event with 60,000 people attending a day. More Info here.
Any one who can use a drill, socket wrench, hack saw, wire cutters, and crimpers can do this project.
- An iPOD through a 12V Car cigarette lighter adapter like this one.
- Cell phone chargers
- Portable DVD player
You can use off the shelf parts from local stores to make this 296 Watt pedal power bicycle generator or buy parts from Amazon.com
Through volunteer efforts, 24 of these pedal power bicycle generators were assembled and used for charging cell phones at a 3 day event with 60,000 people attending a day. More Info here.
Any one who can use a drill, socket wrench, hack saw, wire cutters, and crimpers can do this project.
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Signing UpStep 1How It Works
I hacked together a quick LabVIEW program and some sensors to hook up to the bike generator so you can get an idea of how it works. The chart below shows actual data while it was hooked up in the living room to our Sony play station PS2. The game being played is Harry Potter and the Goblet of Fire.
This test data shows Volts, Watts, Amps, Rear tire RPMs, and Heart Rate. The time period was about 3 minutes.
Note that the green line is actual wattage from the bicycle generator. When you first spin up the bike to about 275 revolutions per minute, about 5 seconds goes by while the alternator is developing a magnetic field, then the internal 14.8 Volt DC regulator kicks in and charges a 2 Farad capacitor.
This is the reason for the big green spike right at the beginning of the chart. After 2 seconds the capacitor is charged, and about 10 Watts of power is being consumed by an AC inverter which converts the 14.8 Volts DC to 110 Volts AC (The same stuff that comes out of your wall socket in your home).
Also note the red line showing that the voltage is stable at 14.8 Volts DC because the built in regulator is doing its job.
Next you will see where we turn on the Sony Play Station and the green line jumps up to 30 Watts.
This test data shows Volts, Watts, Amps, Rear tire RPMs, and Heart Rate. The time period was about 3 minutes.
Note that the green line is actual wattage from the bicycle generator. When you first spin up the bike to about 275 revolutions per minute, about 5 seconds goes by while the alternator is developing a magnetic field, then the internal 14.8 Volt DC regulator kicks in and charges a 2 Farad capacitor.
This is the reason for the big green spike right at the beginning of the chart. After 2 seconds the capacitor is charged, and about 10 Watts of power is being consumed by an AC inverter which converts the 14.8 Volts DC to 110 Volts AC (The same stuff that comes out of your wall socket in your home).
Also note the red line showing that the voltage is stable at 14.8 Volts DC because the built in regulator is doing its job.
Next you will see where we turn on the Sony Play Station and the green line jumps up to 30 Watts.
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Many thanks,
The SDSU Green Campus interns
Great idea...
A 12 Volt 7 Ah battery can store or deliver 7 amps at 12 volt for one hour. Or 12 volts at one amp (12 Watts) for 7 hours.
12 V * 7 A = 84 W
(84 / 296) * 60 minutes = 17
So. 17 minutes. :)
Another possibility since this is for fun and exercise and not about the money why not add the solar panel too. Then perhaps us puny humans could go a few more miles. :-)
For a real challenge, put a car headlight on the bike and see how bright and how long you can keep going.... not long I assure you. Amazing how hard your car engine works for the small amount of fuel it consumes.
There's almost always better things to do than static pedalling, especially intricate productive work with crafts, gardening, cooking, child minding or reading etc. Even go for a walk or bike ride!
Given the abundance now of solar PVs it's far "greener" to use (say) a ~5-10 Watt panel (costing ~US$30-50 ) over a few hours to do the charging instead.
The bike would allow you to get some excercise while, say, watching some TV...which is more productive than just watching TV.
It also works at night, indoors, and on cloudy days.
Granted I wouldn't want to use one of these as my only source of power, that doesn't make it a useless idea. For instance, I can see one of these being great set in front of a tv, turning a mind numbing and unhealthy activity into something a little more "productive" while getting a bit of exercise.
Or you want to do something physical and the weather is nasty (because it's not always sunny). Or your rent and electric bill are both do and you only have the money for the former. Or.. I can think of tons of stuff you can do simultaneously while "static pedaling" (reading, singing or listening to music, having a conversation, etc). Maybe though, once in a while, it's nice to do something sort of meditative and not intensely mental.
Truthfully though, I'm so tired of this idea that people always need to be doing something "productive"! What is productive anyway? What if what I want to read instead of "static pedaling" is a gossip rag? What if I hate kids? Then it's not very productive or positive for me to be minding them, I would think.
I could go on and on and on, but I won't. And I don't mean to be offensive in any way, so please don't take it that way. I just strongly (I won't even go into the "puny" comment...) disagree with you .
But how about the other end of the circuit? Think 12 volt circuits. We need LED lights and even strings of LED lights. Heavy extension cords will conduct 12 volt electricity to neighbors so they can have lights at night, too. They can help charge the battery for the day. They become vested in common security as well.
When things go bad, this is useless for anyone living in a megapolis. The government will relocate the survivors.
Besides, it's more likely that you will tire long before this could be an issue, and car batteries are remarkeably-durable anyway, especially if you consider the harsh conditions they normally operate in.
Car batteries will be badly damaged if drained fully a few few times, will boil off liquid if overcharged. They are not very durable at all if not implemented properly, and don't even last very long at all if you consider the typical car battery might be drained only 5% of it's capacity about 5000 times before it fails in real world "harsh condition" use - this is far below full cycle capacity of a NiCd battery for example.
http://www.youtube.com/watch?v=bJFGEQRWxz8
I'm glad to see more people getting on board with this idea, because countless trillions of watts are lost to heat on exercise-bikes worldwide every day. By actually harnessing this power, it decreases the carbon-footprint of a person/household by a great deal.
Kudos to you for posting this project, because exercise bikes are stupid when they aren't actually salvaging that lost power. 100 Captain-Planet points to you, and a bonus 5 internets for intelligent design in the project.
As a suggestion, you could try weighting the wheel (making sure it's centrifugally-balanced, of course), because while it may take a little more energy to get it up to speed, it would actually reduce fatigue dramatically, having only to maintain the momentum. As a well-seasoned ex-cyclist, I can assure you that you will feel the difference while you are on it. It's much easier to maintain momentum than to sustain it without mass. That's part of why engines have flywheels.
Awesome project, I love it.
http://www.scienceshareware.com/build-your-own-generator-bike-trainer-stand.htm
can you tell how you hook up the AC yeard blow to the DC generator.. I can see some many applications for this. Thanks Colin (electricpedals,com)
But your idea is awesome too. I'd love to have a cike to commute on that charged my electronics as I went...
do you have a measurment or esimate of the RPM of the alternator? automotive (and most others for that mater) are designed to have a minimum of 2000 RPM to operate properly.
from the parts you have constructed i can see that the theoretical max output of your bicycle is approximately 444 watts, but have you even come close to generating that much energy with a single user?
if so, how long were they able to sustain that level?
what was the load that was consuming 444 watts?
The speed is a little harder to calculate. It depends on the ratio of the bike wheel to the wheel of the pulley on the alternator, I am just guessing but 2000RPM Should be possible depending upon what gear the bike is in and what RPM you are peddling.
Pros are a lot better; Lance Armstrong's time trial/climbing output has been estimated at 400-450 watts (he doesn't publish his actual figures, as far as I know).
We (electricpedals.com) are based in the UK and are in the same business! We recently powered an entire house for a science show. Unfortunately you can't see the show in the US, but there is a bit about it here.
I'm now working on a mass mobile phone project for major festivals in the UK and intend to approach this a little differently. That is we've already tested charging about 30 phones from a single bike (although I think 20 is about the limit). We'll use 6x 500 farads of ultracap as a repository for times when we have more riders than phones or vice-versa. These are modular and can also be use to control voltage. i.e. once system voltage reaches 15v we add another cap etc.
Car chargers are defiantly the way forward in terms of voltage regulation!
Good work
Colin
we have a human power tea and toast stall that uses about 10 people to make tea.. pretty efficiently too.
Colin