Pedal Powered Computer: Literally

[Joe Blake]

http://www.gizmag.com.au/mit-cycling-human-powered-computation/8503/

Wow.

Joe

[Rob Beckers]

That reminds me of a science museum exhibit I saw once: They had few light bulbs attached to a bike-powered alternator. The surprise was just how much effort it takes to produce a little bit of light. It underlines how much we tend to take energy for granted.

-RoB-

[Joe Blake]

I did a bit of 'net surfing, and tracked down this link

http://www.windstreampower.com/Human_Power_Trainer.php

They make the generator which the cyclists used to power the computer.

Definitely on the list to Santa Clause.

Been going around working out how much wattage each product in my entertainment centre draws. It MIGHT be possible for me to generate enough power to "entertain" myself. TV (the big power chewer) 70 watts, digital set top box 15 watts, DVD/VCR recorder 27 watts and radio/amplifier rated at maximum of 290 watts, but that's only if I drive it to max volume. I'm not sure how much power it will draw if I stick with using headphones.

I've got a 150 watt 240v inverter, which normally runs off my big batteries, and running all those appliances simultaneously from the inverter causes the fan to operate only intermittently, so it would seem that in total there's less than 150 watts being drawn.

From my own experience at the "exploratorium" with the "light bulb" generator, I found I was being hampered by a lack gearing. I wasn't running out of power, but speed - I couldn't turn the pedals fast enough because the gearing was so low.

Now I'm beginning to wonder whether I'll be able to get enough exercise entertaining myself, or whether I'll need to add an extra load to make me puff. Of course I suppose I can always increase the capacity of the batteries.

Anyhow, will keep you all posted on this little project. Quite literally, I've been wanting to have a pedal powered generator for nearly 3 decades, and each time I've tried to build one, something's sidetracked me. And here they are commercially made. It's about time!!!

Joe

[Joe Blake]

Well, the generator arrived today, and after a bit of sweat and tears (and just a teensy bit of blood) I managed to install it.

http://i82.photobucket.com/albums/j245/saxeharp/gen02.jpg

http://i82.photobucket.com/albums/j245/saxeharp/gen03.jpg

http://i82.photobucket.com/albums/j245/saxeharp/gen01.jpg

I've got the batteries ready, I've got the inverter set up, and I just need to buy a voltmeter and some connecting wires.

I've decided to use the recumbent bicycle rather than a "sit up and beg" bike because I think it is a more efficient position.

It didn't fit my trainer exactly, and I had to buy a longer bolt and make the white PVC tripod bracket to keep the generator pressed against the rear tyre.

However, there was absolutely NO wiring to be done. Everything, including rectifier and reverse polarity protection are built in.

I'm VERY pleased so far.


I'll keep you informed

Joe

[Joe Blake]

An update:

Thanks to being reminded in another thread, I'll tell you what's happened.

Soon after my last post, everything was ready to roll and my neighbour, Don, always interested in my follies (he's a teacher of high school kids and likes lateral thinking) came in to assist. The batteries weren't fully charged, and when I switched "everything" (see previous post totalling up wattage) on, the inverter shut down immediately. Not enough power in the batteries. I then switched it all off and started pedalling, getting Don to switch on items one by one. TV on, not a problem, digital set top box, still handle it, DVD player seemed okay, then the amplifier came on and it all shut down.

I was pedalling at what I would call a "cruising rate", one which I could comfortably keep up for a longish time. I then started going flat chat (I'm not Lance Armstrong but I've managed to hit about 50km/h on the flat using the recumbent bike in the photos), and the inverter came on, went off, came on, went off. So I had too many applications. Don turned the amp off, and I almost managed to keep everything else running, but not for long. I ran out of puff!!

Anyway, after a bit of switching on and off, I found I could comfortably keep the TV running. However, I have in the past disconnected the internal speakers of the TV for various reasons, and I'll have to put them back in circuit before I go any further, since the sound will draw extra power.

As at today's date, (a) I can run the TV on its own without sound. No digital STB, no DVD player, no stereo amp. (b) I can charge up the batteries by pedalling for an hour or so (watching the Tour de France on DVD to keep my interest up) and then run a desk lamp (or even two) containing a 5 watt CFL, for the entire evening (till about midnight) without the voltage on the batteries dropping below about 11.5 volts.

So I've probably spent in the vicinity of $4000 (taking into account the bicycle which I've had for over 15 years) all up to run a small light or two for an evening or two. Value for money?

No way.

But I've put together a workable system and that's much more important.

I guess now it's up to someone else to say "I can do it better cheaper".

;):D

Keep us all posted guys (and girls???) Do we have any ladies on this board? Just curious.

Joe

[Joe Blake]

Update:

On Thursday evening, I was doing my daily pedal for an hour when I heard a strange rattling noise and the voltmeter starting behaving oddly.

On Friday I took the generator to a local autoelectrician who opened the case and showed me - dramatic chord:

http://i82.photobucket.com/albums/j245/saxeharp/windstream/gen01.jpg

a broken shaft.

Wow. Didn't realise I was that strong. Via the magic of digital photography and the internet I sent some photos to the maker in the US, asking whether I could get a replacement part.

Midnight or so last night less than a handful of hours later, a return email:

[cut and paste]


Hi Joe,


I'm going to send you a completely new module ( channel, pillow block, generator etc.) - we redesigned the friction drum and changed the tolerances as we have come across a few snapped shafts, we think due to a manufacturing run we did here about a year ago. There was too much play in the friction drum and that is what caused the stresspoints on the shaft.


I will send it out on Monday - absolutely no charge as should be expected.


Many thanks,


Sheila


That's service.

Thanks Windstream, you deserve a plug.

http://www.windstreampower.com/


Joe:D:D