Re: [Phys-l] flashlight : no battery, no bulb

[Jorge Hoyos <jorge_hoyos@yahoo.com>]

Indeed, no bulb, but they do need battery. No way a
long lastig charge only shaking them.

 
--- John Denker <jsd@av8n.com> wrote:

> The local Walgreens stores are running a clearance
> on flashlights.
>
> This is the kind with an LED instead of a bulb, and
> a supercapacitor
> instead of a battery.  You charge it by shaking. 
> The chassis is
> transparent, so you can see the coil and the magnet.
>
> I like them because
>  -- light weight ==> good for hiking
>  -- no battery ==> near infinite shelf life
>  -- LED won't burn out any time soon.
>  -- small amount of shaking makes rather
> long-lasting light
>  -- physics lesson
>  -- on sale for $2.00
>
> On the other hand, it looks like they were having
> serious production
> problems.  I had to sort through 12 of them to find
> 3 that worked.
> _______________________________________________
> Forum for Physics Educators
> Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l
>