Powering a TV from my Bicycle

[PlayingWithFire]

For years I have wanted to generate the electricity for my television by riding my bike on a static roller with dynamo (like used for training).

I thought this would be the perfect solution to becoming a couch potato, watching the Good Life, Time Team, Ray Mears, any nature programmes, Countryfile, Weather and ok I admit it - Little Britain, Friends, etc.

As a child I was captivated by the bicycle at CAT, on which I peddled and lit up a light bulb. As a pretty fit adult cyclist, I'm sure I can generate a fair bit of power comfortably. I dream of watching the Tour de France whilst peddling away!!!

It is such a waste to convert my energy into heat using resistence on the roller (the window has to be open for ventilation), so I would like to run my TV off it ... only being able to watch TV if I am active! (Hence not charging up a bank of batteries).

(I think of all the energy generated in fitness gyms around the world ... of all the exercise done to get fit and work off that extra pudding, not being harnessed. I got my exercise doing landscape gardening - so got paid to get fit, instead of forking out gym membership. Not so sociable mind).

Can anyone help me with the technology - to generate sufficient electricity from cycling to power a TV (and a reasonably sized colour one, at that).

My mind also thinks of powering my computer this way, plus using wind generators (Orkney is windy!).

Is there a place or website I can learn the necessary technology without having to study electronics?

Can anyone help this idiot?

Thanks ~ M

[Wombat]

G'DAY Malcolm,

In one of my less sane moments I added a roller bike alternator to an exercise bike . It generated about 1 amp when pedaling pretty hard, not full tilt, but pretty hard all the same. I would not regard myself as cycling fit, I mainly walk, but to generate enough power to run a TV based on that sort of system would require the indeible hulk .

I do remeber seeing years ago a design for a bicycle generator that was based on the drive wheel being replaced by a plywood disk and permanent magnets being placed around the rim. I went looking for the details but so far have been unable to find it! I'll keep trying.

Nev

[Sue]

............only just seen this question
I saw that guy on the telly - the one who advertsies the tax returns but seems to know his science stuff too (glasses - you know the one)
He set a young athletic girl up on a static bike to power the TV - it worked but blimey she was working hard, and very sweaty - so you may get a vague picture on your TV but I don't think the smell and the doctors bills would warrant the effort
Much better for you would be the static bike, at a reasonable pace, and get some extra exercise for your belly by laughing at Little Britain (and digging the garden of course)
How do you find time to watch TV - everyone on this site seems so busy digging / planting / picking etc !?
For those interested by the way - my veg patch is dug - but I spent the weekend filling a bin bag with dandelions (yes I know I should have eaten them and made wine etc but I was a girl on a mission and theres nothing more rewarding than knowing a jobs well done - I wanted to see the back of them - sorry)
Is rocket easy to grow - I fail every time with herbs, but is it more hardy?
Lee & Ian (Darkwood) let me have some rhubarb and that is going in next to red & black currants and raspberries - yum

[wulf]

You'd probably want some kind of battery (electricity storage area) in order to deal with voltage fluctuations - use the cycling to top up the energy reservoir. For the kind of things you're talking about, it sounds like your ideal system would actually feature an energy reservoir that you can top up from various sources, such as cycling, wind power, solar power, etc.

Of course, at this point I have to admit that I've got none of the practical knowledge needed to take it further... just a web designer who's read a few books!

Wulf

[Andy Hamilton]

A load bell started to ring when reading this thread. Many moons ago I used to protest against the criminal justice bill. (Which actually makes morris dancing against the law!)

A bunch of people would always turn up with a cycle powered sound system I did a quick google and came up with this http://www.stewardwood.org/resources/DIYcyclepower.htm - tells you how to make your own.

Incidently a telivision seems to use the same amount of electricity as a cooker. http://www.selfsufficientish.com/greenelectricity.htm

[Muddypause]

I remember an old lag commenting about some busy office type who had just bought a keep-fit machine - "Huh! I've got a keep-fit spade in t' shed."

I've been looking at my old A-Level physics book. Please bear in mind when reading this, that I failed the exam! Twice!!

First of all, I'd find out how much me and the bike weigh. Then I'd find a long hill that I am able to comfortably cycle up without stopping, and find a way to establish its vertical height (or the vertical height of a section of it), and then I'd time myself cycling up that hill (or section of it). This would tell me that I've raised x kg through y m in z s. On planet Earth, lifting 1 kg through 1 m in 1 s takes about 10 Watts of power. To put it another way, to light a 100 W lightbulb for 10 seconds is the equivalent of a 10 kg person (+ bike) cycling up a hill 10 m high in 10 seconds (this ignores losses due to wind resistance and friction). From this, you should be able to work out how many Watts you produced when you cycled up that hill.

Now, bear in mind that a good generator, and any circuitry involved, may only be 75% efficient (? this is a guesstimate - in terms of back-of-envelope calculations, it may be OK to offset it against wind resistance and road friction if you are using a static cycle to generate with).

Now find out how much power the telly uses. You will be able to work out the equivalent of how many meters per second that is the equivalent of cycling upwards. For every 10 W it is the equivalent of 1 kg going up 1 m in 1 s / 75%. To watch the Good Life on a telly that consumes 100 W, if you + bike weigh 100 kg, you are doing the equivalent of cycling upwards 1.3 meters per second every second for the duration of the programme. That's equivalent to travelling at 20 mph up a gradient of 1 in 7 for half an hour.

Phew. After all that I'd definitely need a cream cake to recover with.

As I understand it, a problem with low volt electrics, is that the lower the voltage, the bigger the diameter of the wire needs to be, otherwise significant losses are incurred over distance. Given the cost of large dia. copper wire is expensive, you may need to factor this into your calculations.

Anyway, for wind power, up in your part of the world (well, Scotland, anyway - I know it's a big country) I found this:

http://www.scoraigwind.com/

and this seems a useful link, too:

http://www.andrew.h.lohmann.btinternet. ... html#Links

These sites have been in my bookmarks for years, and amazingly I have just realised that the second one is by a friend of mine. I never knew he had an interest in wind power.

[PlayingWithFire]

Agree!
I should of course make it clear I am not a complete nut (otherwise I would not be here on this site) and there will be times we want to snuggle up on the couch and watch a film together ... and relax!

Multiple power sources cetainly seems essential but I like the idea of working hard enough to watch the Tour de France or the Rugby World Cup Final (Go Wales!!!).

I guess my ideal scenario is through a battery, or whatever electrical device evens out curent / voltage.

Of course - we rarely have time to watch TV - no soaps or "reality shows" - and in the UK the cost of a TV licence can make such limited viewing questionable ... but, since we got a TV six months ago, we have been delighted by the programmes (usually on BBC2 or Channel 4) about archaeology, history, environment ... and it keeps us in touch with society a bit.

[PlayingWithFire]

Many thanks Stew!

We went to Scoraig but never met the people - it being mid winter.
Thanks for the prompt.

Where in the country are you?

[Muddypause]

Where in the country are you?

Beautiful Berkshire (for variable values of 'beautiful', of course. I'm still looking for the bloke that put the Berk in Berkshire).

I've lived here in a big town that now thinks it's a city for far too long, but have lived in various parts of England. I'm not a city boy by nature, and I'll go stir crazy if I stay here much longer. Soon I'll be old.

I've just been looking at the bluewoad site that you gave a link to elsewhere. The travelogue is excellent. I've visited parts of Scotland often, and with the cost of property being what it is in England, I have a half plan to move there one day. But I see prices rocketing there, too, now.

One day I'll get some finance together that will enable me to move. One day.

[PlayingWithFire]

Thanks for comment about Bluewoad - I'll tell Rachel.

A lot of folk are selling up property in the south and buying "palaces" in Scotland for a the price - with left over to invest / live off. Crazy - and not good for us locals - is driving the prices up. But will never be as expensive as over crowded south.

We don't know congestion.

I used to live in Windsor, and had a spell in Ascot and Fleet (Hants). I got out quickly - in the 90's. Couldn't afford to go back even if I wanted - and I don't!!!

If anyone reading this wants to see Rachel's website, it is at:
www.bluewoad.com

[Just_A_Visitor]

For years I have wanted to generate the electricity for my television by riding my bike on a static roller with dynamo (like used for training).

If you'll forgive a vistor for butting in -- this has got to be one of the best descriptions I've found for what you want.

Anyone interested in DIY electricity generation should definitely look at the rest of the site, starting from http://www.otherpower.com/.

HTH,

Nigel

[PlayingWithFire]

Many thanks Nigel ... a very interesting website!

All the best
~Malcolm

[judyofthewoods]

The otherpower website is brill, thanks.
Andy, the cycle powered sound system is probably Rinkidink, isn't it? Or similar name.
I have used a pedal generator myself, and my own experience backs up Wombat's figure of 1 amp for sustained pedalling. See this thread on the green-trust forum http://www.green-trust.org/forum/viewtopic.php?t=208
for a few extra coments.
There are three ways you can iron out the Voltage fluctuations, 1) a fly wheel (e.g. an engine flywheel from a car from a brakers), 2) battery, 3) capacitors (quite large, and expensive). There is an article on capacitors with cycle generator in one of the Home Power magazines. If you are not in a hurry, I will get the info, perhaps scan the article and post it on my website along with all other info I've gathered on pedal generators.
I would definately not go for a car alternator as they take a fair bit of energy to power the field coil, and need a very high rpm, which means a lot of gearing and power losses. Best thing is a permanent magnet motor.
Televisions vary greatly in their power consumption, depending on size, colour and type. A flat screen colour TV will consume about the same as an equal size B&W cathode tube TV. A large ct colour TV is out for pedal power, unless the whole family are pedalling away at the same time. Some figures from own experience:
5" B&W TV approx. 5W
5" TFT colour TV approx. 5W
12" cathod tube colour TV approx. 56W
Personally, I would forget about pedalling for TV, at least not whilst watching as anything but very leasurly pedalling will interupt concentration or prevent relaxing to a good film. To get a bit of extra exercise and be productive at the same time, I am working on a pedal universal machine. It will be an old excersise bike converted to drive various tools and kitchen equipment, like a laithe, drill, saw, juicer, grain mill, grater, etc. which don't require quite the same concentration

[Wombat]

Judy,

Is that similar in design to the one in the "Pedal Power" book?

Nev

[whitelegg1]

Quick thought...

Would it be possible to have the gear set up as follows to create a much higher gearing.

Have a largest front ring you can find/fit, have the smallest rear cog you can find/fit, then also at the rear have one of the 'megarange'tm massive rear cogs.

Run another chain from this to the cog on whatever you will be using to actually generat the electricity.

I may be missing something but I tought chains and gears were an incredibly 'efficient' way of transfering power.