[shadowbot]

The other day I went to a watch store and saw some of those kinetic watches, you know, the kind that never needs a battery or winding. It has a mechanism that creates energy just by using your natural daily movements.

Now I was wondering about this technology and if there are other possible uses for it. For example, could we keep our cell phones charged longer by capturing the kinetic energy of them flopping around in our pockets as we walk? Phones are already so small they can fit them into the frames of sunglasses, phones can already be made smaller than would be convenient to use, a lot of companies are stuffing this extra space with cameras and hard drives for mp3s, but what if this space was filled with devices that could convert the energy of a walking person to power?

[Raptor235]

hmm interesting idea... I have one of these watches... I'm not sure though what the potential energy generation would be... I mean to run a watch the energy required is probably very very small... and these days the electronics seem to use up battery power very very quickly... there still might be some other types of devices you could apply this technology to...

[shadowbot]

Yeah, you are definitely right in that regard, I was thinking maybe those tiny mp3 players that use flash memory and last ages on 1 AAA battery might be good candidates. Especially if it was something you were going to take jogging and if it was an activity where you knew you would be moving. Although I dont know what kind of power output you can get from it either, so it might be possible that the energy produced might not nearly be enough.

[Matc]

Some rough figures I've worked out

If you have a good rechargeable AAA battery it would be about 600mAh which is 3240J of energy.

Say the mp3 player weighs 100 grams and you were turning all of the gravitational potential energy into electrical energy. You raise your arm once a second whilst you run and the run is for half an hour you'd be looking at about 1000J.

But the systems in use do so by causing a pendulum to swing which works a miniature generator. So it is only the pendulum that generates the energy which at a fraction of the mass couldn't hope to run the mp3 player

[Raptor235]

when it comes to electricity I have no clue whats what...

[horselover]

I know the feeling. All I know is that you plug something in, a current goes through it and it works. Same goes for humans being electrocuted. The juice goes through. Happened to me a few years ago.

[shadowbot]

Originally Posted by Matc

Some rough figures I've worked out

If you have a good rechargeable AAA battery it would be about 600mAh which is 3240J of energy.

Say the mp3 player weighs 100 grams and you were turning all of the gravitational potential energy into electrical energy. You raise your arm once a second whilst you run and the run is for half an hour you'd be looking at about 1000J.

But the systems in use do so by causing a pendulum to swing which works a miniature generator. So it is only the pendulum that generates the energy which at a fraction of the mass couldn't hope to run the mp3 player

So theres not nearly enough energy doing it that way.
Maybe we can somehow capture the energy of when your foot slams into the ground every time you take a step, all your weight slamming into the ground once per second, and all that energy is transferred to the ground where its lost. Theres an idea.

[Matc]

Yeah, you could use a similar system to regenerative breaking in cars. Your limit would be in not creating any more noticeable work for the person (you don't want to be able to feel your shoe resisting you)