well engineered motion into electricity device

[Temporal Visitor]

It is interesting but don't count your chickens yet.  It doesn't make sense to put one on a truck because the energy it would harvest would come from the diesel fuel you put into the truck.  It's a fancy arrangement of clutches.

It makes more sense when you begin the design starting with an electric motor or flywheel driven truck. 

[memoryman]

and where does the energy come from that goes into the flywheel?

[conradelektro]

One of their videos shows a tennis ball sized device that is able to produce 4 Watts by human walking speeds:
https://www.youtube.com/watch?v=JLdBglIryQk

Yes, precision machining and making the gear wheels have become very expensive, I wonder if the use of 3D printers  could reduce the costs somewhat.

PS here is their video channel: https://www.youtube.com/user/wittlimited/videos?shelf_id=0&sort=dd&view=0 

I read some time ago that the US-Army did some tests with boots which heels were energy harvesters. (I did not find any info on the Internet easily, so I gave up.) A very simple system, at each step the heel moved in a few millimetres pressing on a gear which in turn drove a small dynamo. The output was a few Watts for a smart phone type device which connected via satellite to battle command. The idea was to know the location of each soldier and to command each soldier remotely.

To make the story short, the soldiers wearing such boots tired much more than soldiers with ordinary boots. It is real work to generate a few Watts.

Therefore I have the opinion, that one should design a small device carried in a trouser leg (not bigger than a watch) which generates not more than 100 mW. One will not notice such a load. The power output cable from such a small device should be woven into the pants leading to a smart phone holster or pocket at the waist or hip. But such a device will be expensive because it has to be a mechanical marvel (like a self winding mechanical watch). I think it could be done with a miniature WITT gear, but it will be a novelty item for rich people.

Greetings, Conrad

[lancaIV]

http://www.gizmag.com/low-cost-large-area-piezoelectric-nanogenerator/22468/?li_source=LI&li_medium=default-widget

[conradelektro]

http://www.gizmag.com/low-cost-large-area-piezoelectric-nanogenerator/22468/?li_source=LI&li_medium=default-widget

This is a nice piezoelctric pad. If you read the paper http://fand.kaist.ac.kr/Attach/NCG.pdf mentioned at the end of the article, you will see that a 5 cm x 7 cm pad tapped every 2.5 seconds can dimly light a red LED. I estimate this means about 1 mW.

It looks like a piezoelectric substrate is a bit brittle and will not last very long if pressed hard. A piezoelectric device is good for a high Voltage burst every now and then, e.g. for a lighter.

WITT is right in believing that the output of a mechanical precision gear can be relatively high in comparison to piezoelectric pads or even solar panels of the same size. A good mechanical self winding watch costs at least 1000.-- Euros, even more. That points to the price range of a small WITT gear.

May be one can build a WIIT gear swinging in the wind instead of a wind wheel. E.g. a multi winged blob with a 1 meter diameter suspended from a bridge like construction. It is hard to estimate the output. If it is about 1 Kilo Watt in gentle winds, it could be useful. A wind wheel is also rather expensive and mechanically challenging.

Greetings, Conrad