> LED clothing! > > =A0All it needs now is a solar panel as a hat to provide the power or > some mechanism to turn body movement into a gyroscopic power > generator. > > 000-leds.1166352.lynkx?utm_source=3DUK&utm_medium=3Demail&utm_campaign=3D= new > s> Dunno who the LED guru is, but PV panel in hat is definitely on the maybe list. Basic ideas have been tossed around but not tried yet. As for the clothing - so far I've only managed a PIC controlled "angel's halo" for my daughter, long long ago. It was a real hit. Basic left and right light chaser and several flashing patterns which changed in sequence. Add gliitery string and some furry stuff and viola. Very effective in the dark. Not so good in higher light levels. I know an aspiring clothing designer who would love to build something around a LED array. It is by no means original, but a useful headlight could be reasonably well served by a PV panel that could be comfortably enough fitted into a cap. Top of head may be best insolationally, but top of peak of a cap would probably be more practical. You could probably hope for about 50% of full output on average in bright sunlight. Shading would need to be avoided or dealt with. In a multiple in series PV cell system the current output is approximately limited to the output of the most shaded cell (unless shunting diodes are fitted.) Shade one cell badly and ther whole panel output plunges. One way to deal with shading is to use a single PV cell so that the output is proportional to mean illuminatiion of the whole cell. You then have to deal with the very low voltage of say 0.2 to 0.6 Volt depending on shading. People offer ICs that boost from this level using synchronous conversion to help efficincy, but the FETs need to have nicely low Rdsons and tracks and wiring and inductor need careful attention. Up conversion efficincies of over 85% are claimed by some. It would be really easy to get less than that if great care was not taken. I've considered mechanical body movement generation of various sorts but done only basic playing. Hand crank units usually don't give more than a Watt or so (I've measured them) - but this is usually due to the shocking mechanicals. I can get 10 Watts with no apparent effort from foot or hand "pedalling", 50 Watts can be done continually with not too much effort, 100 Watts is bearable for long peruiods but annoying. Higher starts to be real exercise (for me). I can personally do 500 Watts pedalling for only perhaps 10 seconds. (Gossamer Condor piloting will never be within my reach). Russell McMahon > > Colin > -- > cdb, =A0 3/07/2009 > > -- > > > > > colin@btech-online.co.uk > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist -- = http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist