using weight for generating

[Norm]

Here is how to determine roughly the amount of rpm and torque to achieve
the necessary watts to operate a device..........

at the bottom of the picture a empty thread spool glued to
the shaft of the stepper motor (to the left)
motor was clamped in a vise and thread going up to the ceiling
weight of the pennies was allowed to unwind off of the spool pulley
about an inch in diameter ....it traveled about about 1 ft. per second
(60 ft. per min).
  So if that amount of current would charge a cell phone battery   .

   If anyone would like to try this could draw you a more detailed diagram.
although I've never charged a cell phone battery .....would 3 AA batteries
be equivalent ?
 
   So this is one subject regarding a weight powered generator .....NoStahl

 Norm  

[MadScientist267]

I'll take a stab at the math (hah, we all know how THAT goes with me)... but jokes aside, something like this:

You're making 40mA at 4.28V going by the notes in the pic, yes? I'll run with that.

Let's say you want to charge my phone... it has this in it:



So you need to generate 3500mAh to charge it from completely discharged.

There's conflicting penny drop rates, but there's easy resolve if one of them is calculated. Let's go with the 1 ft per second for now to make the math easier...

1 ft per second, 60 ft per minute, 3600 ft per hour.

So 3600 ft would be 40mAh of energy.

The battery will need 3500, so 3500/40...

87.5 hours for a full charge.

3600 ft per hour for 87.5 hours:

315,000 feet the pennies would need to fall...

~59.66 miles of thread...

Ok, now for the "2 seconds per foot" version...

Still talking just shy of 30 miles of thread.

Even spider silk won't give you enough strength with a small enough diameter to cram all that on a spool that would fit on a stepper... unless you know something about physics I don't

So, as they'd say on a certain TV show, "Myth Busted"

Anyone, please, feel free to correct any logic/mathematical issues, but I think I got this one nailed. Sorry Norm 

Steve

[rossw]

So, as they'd say on a certain TV show, "Myth Busted"

Anyone, please, feel free to correct any logic/mathematical issues, but I think I got this one nailed. Sorry Norm 

There you go again, ruining a perfectly good plan with facts.

Perhaps instead of 315,000 feet of thread, stick with the original 3600 feet and use 88 pennies.
Or 880 pennies and a 360 foot fall!