Dynamo to power a Television...2wks left!!!

[beatsnpieces]

Hi

First timer here, i have a project in which i need to power a television or perhaps any other household electrical appliance, by the use of a dynamo on a bicycle, can anyone please help me? will i need to build quite a big dynamo!?!?

[gen2]

I don't think a TV will cope very well with the variations in current/voltage that pedal power will generate. Are you allowed to go via an accumulator?
pedal => dynamo => accumulator => inverter => TV

[rojash]

Well, according to this site:

http://www.myra-simon.com/bike/dynotest.html

The best rated bicycle dynamo could provide 4.5 watts at 40 kph. So I would think you will need about 15-20 to power a TV, and you will need to leg muscles like the incredible hulk!

[gen2]

It has been done before many times, but not with a the small dynamo's that are designed just to provide cycle lights. You need to get the cycle chain to directly drive a larger dynamo/generator/alternator.

Here is a site explaining how a guy in America has done it. http://www.los-gatos.ca.us/davidbu/pedgen.html

[beatsnpieces]

hi, jus wanted to say thanks, i didnt think anyone would answer so fast. any idea how much it would cost?

[beatsnpieces]

yeah i can can do it any way, as long as itll provide electricity to an electrical socket, so i may plug inany appliance

(pedal => dynamo => accumulator => inverter => TV )

and where would i get an accumulator or an inverter? would this be the easiest/best way?

[qapmoc]

First thing to do is read the following to get some idea how much power you are going to be capable of producing, I would say for most people (i.e TV slobs) it is going to be pretty low. 1hp=746Watts.

If I was going to do this (cost not included) I would get a car type alternator and run it from the bike and then use it to charge a 12 vdc battery and then power a 12vdc/230vac invertor to get the 230vac, or if you have a UPS available then use the alternator to directly charge the 12vdc battery of the UPS and get the 230vac from the UPS output. Make sure you use a UPS that will ''cold start''. this means that it will power up without the mains supply being present. (not all small UPS do this)

A maximum of about 1 to 1.25 HP for cycling is generally assumed. An article describing tests human subjects cycling, "Maximizing Human Power Output..." J.Y Harrison, U of Wales, Sydney AU, one subject ranged between 1.75 and and 1.2 HP within the first 1/2 min and this dropped to 0.4 to 0.5 HP after about 3 minutes.
This article also states: "For durations of more than 5 min., the average rate of hydrolytic energy release is quite low, corresponding to less than 0.1 h.p., so that the total power output is governed mainly by the steady state oxidative component of about 0.4-0.5 h.p., and this rate of power production can be maintained for a considerable period of time, of the order of an hour or so."

[beatsnpieces]

sweet, well the television doesnt really need to power for a long duration of time, its supposed to be an interactive installation within a science museum, so its creating awareness about how much energy were using when we watch television. as for cost, i suppose less than �100 would be nice :P lol. Im gonna have to research in to these parts you mentioned. thanks.

[beatsnpieces]

the only types of 12v - 240v invertors i have found, seem to only have a car cigarette lighter, will the proces of connecting it to a car battery be as simple as to cut the cigarette lighter plug off and strip the wires and connect them to the car battery? and also, how many watts should the invertor be for a television? please help!!!!!

[Hamish]

It might be easier to run a car radio directly off a car altenator/bike set up - no need for the inverter. Or possibly to set up a series of car head lights and run these directly off the altenator - then you could turn more and more on and see how they dim when you have a lot turned on at once.