| T O P I C R E V I E W |
| gotwind |
Posted - 24/12/2007 : 16:32:18
Another option for small scale wind power might be to use the Freeplay Freecharge mobile phone charger as the basis of a project.
It is capable of 16 watts+, far more than the dynohub, but does use a gear train that does cause some power losses.
However for £16 you have a reasonable wind generator as it requires 120 rpm to get 12 volts, so the 4 Ft prop would be ideal.
The voltage is regulated to 14.2 volts, so this may need looking at, and coupling the prop to the winding handle may take a bit of thought also.
I'm sure it could be done - It may not last very long, but you never know, the plastic gears are of a very high quality.
http://www.gotwind.org/freeplay_energy.htm
Video here
http://www.youtube.com/watch?v=NI95R-i7m6U
Detailed specification here
http://www.freeplayenergy.com/products/portable-power/mobile/freecharge12v/specifications
Center idler gear removed.
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| 4 L A T E S T R E P L I E S (Newest First) |
| ghurd |
Posted - 03/01/2008 : 16:27:43
Not in mine. Pretty much just a geared up, rectified stepper motor idea. Impressive ratings, 6V at 500ma.
5 white LEDs, a red blinking incandecent, a USB output for charging cellphones etc, and can be charged (as in 'overcharged' through a resistor) from a 12VDC source as well. Even has a red/green LED, red is cranking too slow, green is charging the battery.
Norm gave it to me a year or 2 ago, think he paid $4! |
| fungus |
Posted - 02/01/2008 : 13:06:22
ghurd;
I do notice something similar with my wind up light , charging NiCds - less torque once you get to higher speeds.. must be a regulator of sorts? |
| ghurd |
Posted - 02/01/2008 : 07:59:50
Very strange...
Using my generic wind-up flashlight yesterday (geared PMA), I noticed past a certain RPM the power needed to turn it Decreased. The PMA charges AA Ni-Cds for the LEDs.
After cut-in, the power needed to turn it increases. That is about 60 RPM.
Somewhere around 100~130 RPM it feels like it is unloaded.
My best guess is the coil inductance reduces the output to near 0W.
Do you notice anything like that?
G- |
| ghurd |
Posted - 27/12/2007 : 06:13:25
I doubt it would last a day in a good breeze.
I know of one that was worn out in 8~12 hours by hand.
I don't know the PC or medical terms, so I will leave it at it was worn out by hand by one enthusiastic person in less than 12 hours.
G-
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