young scientist by bike !!!!!

jimbo28

Guys

This maybe the wrong forum but Im looking for some valid advice and/or ideas. Had a few of the kids approach me in the school with regards to getting a bike to power a number of 100 watt bulbs in order to cook something small like a chicken!!!

Ive seen it done before on some tv programme but wondering would anybody have any advice on the set-up required for such an experiment.

My own thoughts would be that a bike mounted on a turbo trainer connected to a generator( type size etc? how would you even go about it!) with a way to measure the output being produced ( power metre/analogue watt metre/ type etc????) connected to a chargeable battery which in turn could feed the bulbs with the required power.

i cant imagine it would be too hard, maybe use a v belt/square belt to drive the generator etc. but i dont have any idea of the tpes of battery that could be charged up or the connections required to connect the generator to the battery. also, could this battery be charged as it is being used? or would one require an uninterupted power supply to power the lights.

Cheers guys.................Beasty this sounds like something u might know about?

Beasty

jimbo28 wrote: »

Beasty this sounds like something u might know about?

I'm vegetarian, so don't cook chickens;)

I also suspect there are others on here that would know a lot more about this sort of thing - I like to take things out of boxes and follow the instructions (or simply plug something in) to make it work!

Beasty

Here's a link to the BBC report on cyclists powering a house

kona

I'd change my heat source from light bulbs as I'd imagine the effort required to power maybe 10 100w bulbs for close on 5 or 6 hours would be huge. Either that or maybe try boiling noodles or something, Id say getting a litre of water to boil would be far more achievable for the lads and the resources available.

Ive never cooked a chicken in my life but I know it takes quite awhile in a oven which would be far more efficient, and dont they go into the oven at near 200 degrees?

Canis Lupus

kona wrote: »

Ive never cooked a chicken in my life

Dear oh dear. Youngsters today :P

kona

Canis Lupus wrote: »

Dear oh dear. Youngsters today :P

Not my fault, I can cook chicken breast etc etc , just never a whole bird!

Jawgap

This was posted by Doctor Bob on another thread:-

http://www.mayapedal.org/machines.html

It might give you some ideas.

07Lapierre

jimbo28 wrote: »

Guys

This maybe the wrong forum but Im looking for some valid advice and/or ideas. Had a few of the kids approach me in the school with regards to getting a bike to power a number of 100 watt bulbs in order to cook something small like a chicken!!!


QUOTE]


Bulbs? to cook a chicken??... Would it not be better to use a bike to generate electricity and then use the electricity to power a microwave oven or something?

Hungrycol

I believe the ESB did something on bikes powering a power shower or some such at Oxygen festival. They might be worth a call and could probably help out with some converters.

mcgratheoin

It's going to be tough-
link

simply powering a hairdryer relied on the efforts of 18 cyclists. It took nine cyclists to power the toaster. And boiling the kettle, something most of us do a number of times a day, requires the combined effort of 30 cyclists pedalling as fast as possible.
The list goes on: three cyclists for the television, 11 cyclists for the vacuum cleaner, 15 cyclists for the iron, 14 for the microwave, 17 for the washing machine, 24 for the oven and an astonishing 70 cyclists pedalling at full-pelt just to power the electric shower.

If it's a science experiment then you can set it up to be very worthwhile regardless of whether it is possible or not to cook a chicken.
Firstly, measuring power requirements of appliances in terms of cyclists is an interesting way to communicate energy use to a young audience.
Secondly, it could prompt an investigation into energy efficiency, for example try to boil a litre of water using one bike - by effectively insulating the container as much as possible.

In terms of the setup, as direct a coupling as possible would seem desirable, I'd imagine that you'd lose quite a bit of efficiency in the transmission along a belt drive otherwise - it would be a good chapter in the project to get a loan of a powermeter (for the bike) and compare the power generated at the pedals with the power seen at the generator - this would provide another set of variables that could be tested.

Sounds like a great idea, keep posting or PMing people for any advice here.

adrianshanahan

Hi,

Trying to generate enough power (watts) to power a heating element for a substantial length of time would be quiet some achievement.

However there would be some merit to using the likes of a leisure battery to power a small microwave and having your bike / bikes generate power to keep the leisure battery charged up. The batter would act much like a capacitor ensuring a constant flow of electricity to the microwave.

I'm a civil/structural engineer so the electronic stuff is a bit vague.


A

Jawgap

adrianshanahan wrote: »

Hi,

Trying to generate enough power (watts) to power a heating element for a substantial length of time would be quiet some achievement.

However there would be some merit to using the likes of a leisure battery to power a small microwave and having your bike / bikes generate power to keep the leisure battery charged up. The batter would act much like a capacitor ensuring a constant flow of electricity to the microwave.

I'm a civil/structural engineer so the electronic stuff is a bit vague.


A

What's the difference between a civil and an electrical engineer?

Electrical engineers build weapons - Civil engineers build targets:)

mahoo

id say you'd need a lot of bikes to cook a chicken. and i dont think the food safety authority would be to happy with your methods ... i saw a lecture where they had 6 people peddling to provide power to the projector. not sure how many watts it was but people were swapping over all the time to keep it going. you could also charge your phone down at electric picnic by pedal power which i thought was cool. chickens though...

07Lapierre

adrianshanahan wrote: »

Hi,

Trying to generate enough power (watts) to power a heating element for a substantial length of time would be quiet some achievement.

However there would be some merit to using the likes of a leisure battery to power a small microwave and having your bike / bikes generate power to keep the leisure battery charged up. The batter would act much like a capacitor ensuring a constant flow of electricity to the microwave.

I'm a civil/structural engineer so the electronic stuff is a bit vague.


A

What about grilled chicken?. Seriously? Is it feasable to use a bike (or two, or three) to charge 12v batteries, which could then be used to run one of these?

kona

Maybe you could cheat a little, how much power does it take to energise the outer coils of a DC generator?
Perhaps energise these either via a battery or a plug , then rotate the generator by a bike, this should yield some voltage.

or

Look into perhaps using a battery to power the bulbs, but, have a alternator to replenish the voltage.

Work out the maths first an you will find out fairly quick if its realistically achievable or not

adrianshanahan

07Lapierre wrote: »

What about grilled chicken?. Seriously? Is it feasable to use a bike (or two, or three) to charge 12v batteries, which could then be used to run one of these?

Seriously?

Well without doing the full maths on it I'd say it feasible for sure. The voltage of the device is not the biggest factor at all, that grill draws 40A/480W to operate, if you had something like a 220 ah leisure battery it would grill your chicken now bother at all without charging I reckon.

You have a bike/bikes charging the battery during the experiment.

So if you were to use a voltmeter to measure battery bank voltage and an ammeter to show net gain or loss of power you could prove that your chicken was grilled on the energy of the peddle power and possibly even the battery gained additional charge during the process.

Thats all off the top of my head but I'd say its more than possible.

A

07Lapierre

adrianshanahan wrote: »

Seriously?

Well without doing the full maths on it I'd say it feasible for sure. The voltage of the device is not the biggest factor at all, that grill draws 40A/480W to operate, if you had something like a 220 ah leisure battery it would grill your chicken now bother at all without charging I reckon.

You have a bike/bikes charging the battery during the experiment.

So if you were to use a voltmeter to measure battery bank voltage and an ammeter to show net gain or loss of power you could prove that your chicken was grilled on the energy of the peddle power and possibly even the battery gained additional charge during the process.

Thats all off the top of my head but I'd say its more than possible.

A

Thanks for that, didn't mean to ask a stupid question...I'm no electrical engineer.

dubmess

ERP are the company that did the bicycle powered mobile phone charging at Electric Picnic this year:
http://erp-recycling.ie/index.php?content=211

I guess they'd be good guys to get in touch with.

Fi H

ESB did something similar this year at electric picnic powering an electric shower by bicycle. Maybe contact them to see if you can find out how they did it.

victorcarrera

Google "bicycle generator" will return lots of interesting stuff.
Here is one I read and is the commercial version of what you need.
http://www.econvergence.net/electro.htm

If you want a cheap DIY version my advice would be to use the student's complete bikes and get your materials technology students to build suitable alternator frames from box section metal to suit the rear wheels.
Local car scrap yards might donate or loan you the alternators and batteries. There is no need to use new batteries as they will only be required to smooth the output and maintain the output voltage during cyclist changeovers etc.
Most modern alternators have built in voltage regulators which can supply the 14.2 volts to power an inverter and charge the batteries and I think the pully wheel on the alternators might just fit a racing bikes 19mm to 23mm tyre.
If you intend using a 220/240 V AC (Mains) appliance you will need an inverter of the appropriate wattage to convert the DC Battery voltage back to AC. They can be bought second hand on ebay very cheaply.
You may need and auto electrician or similar to advise on connectors, cable dimensions and fuse ratings.
A competitive cyclist might be able to maintain 300 watt hours but i would budget for half that for the untrained.
Best of luck with it.

-Chris-

There was going to be an outdoor cinema on Fade St that was powered by bikes for Car Free Day this year.
I'd find out who was organising that and see who they were getting the bike generators from.

DirkVoodoo

The show you are thinking of is "bang goes the theory", they did the human power station as a feature episode last year. It was very good, you can see how the power shower suddenly increases the load to breaking point on the cyclists. They had a lot of volunteers going throughout the day, not sure of the setup:

https://www.youtube.com/watch?v=C93cL_zDVIM

boege

Victorcarrrera suggestions are similar to what I would have thought.

Factor in the losses in the system and you may be lucky to see 70W for every 100W of cyclists power.

An oven to cook a chicken will use about 7kW and take a couple of hours - based on my efforts on a trainer with a power meter I estimate about 100 cyclists pushing out 100W average over this period would do it.

Above all else use a qualifed electrician to put it all together.

manwithaplan

The chicken will not replace the calories burned. This is a recipe for the extinction of the human race. Stop it now before you kill us all;) .

Nietzschean

mcgratheoin wrote: »

It's going to be tough-
link

from that page wrote:

'An average human can maintain 40 to 50 watts for an hour, whereas someone like record-breaking Tour de France cyclist Lance Armstrong could maintain 400 watts for a couple of hours, which could provide adequate power for an electric drill or a 42-inch plasma screen with games console.'

the average human? must be horribly unfit, 40 - 50 watts is a miserable amount of power for even someone pretty unfit if they are only doing an hour. Average by most boardsies here on an 8+ hr spin is still 160+ enough to power a 40" lcd tv


for comparason
http://www.scribd.com/doc/12652072/Human-Walking-Ref

suggests the average comfortable walking speed for a human results in an 80watt power output(after internal inefficencies are taken into account).


Granted none of this is too useful if you want to run an oven...though string a few people together and you'll get a microwave?

jimbo28

Thanks a mill for all the input guys. looks like the chicken idea may well be cooked :rolleyes:. gonna look into powering something a bit smaller.................and concentrate on the energy conversions taking place, maybe try to link calories to watts to temp etc, and as mentioned by one of the guys, look into the energy losses from each conversion also by comparison of values and outputs. if anybody has any other input it would be great!! by the way its more of a practical feasability exercise more so than an experiment.........so although the chicken might be too big a bite to chew........it would be cool to see something actually work..........Im sure the kids would be chuffed with their efforts.

RoubX

Here is a gym using their clients to power the lights.

Victor

You might have them looks at the effect of energy in its various forms - 100W of sound is a lot more impressive to the human senses than 100W of heating or light.

Or consider the specific heat capacity of various materials - it takes a lot more energy to heat water than most metals.

petethedrummer

How about some sort of pedal based power measuring system? So it can be transferred easily between bikes. And make it ANT+ compatible while you're at it.

Or how about a bicycle powered one of these?

rflynnr

Rock the Bike in California do these which might address the OP's query. I've ordered stuff from them before (the "down-low glow" if you must know) and the cost of carriage was pretty reasonable.