Electronic Circuits and electronic circuits, electronic schematics plus an extensive resource for hobbyists, inventors and engineers

DiscoverCircuits.com, has 45,000+ electronic circuits, cross-referenced
into 500+ categories.    We have searched the web to help you find quick design ideas.
We make every effort to link to original material posted by the designer. 
Please let us if you would like us to link to or post your design.

HOME Schematics Index Hobby Corner Dave's Circuits Electronic Resources Contact Info
Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches


DiscoverCircuits.com -- Hobby Corner
Last Updated on: Thursday, November 30, 2017 07:42 AM

Hobby Circuits List

The contents & graphics of Discovercircuits.com are copyright protected.
LINKING to Dave's circuits is permitted but DO NOT COPY any files to your WEB SITE server

 

Shake to Charge Flashlight -- of 4
designed by David A. Johnson, P.E.

Have you ever wondered how some of those “Forever” flashlights work?  These devices appeared several years ago and are often sold on some TV home shopping networks.  A company in Colorado:

(Applied Innovative Technologies www.appliedinnotech.com) made the original device but knock-offs from China are now popping up everywhere.  That fact that some of those devices don’t even work will be a topic for later discussions.

Circuit Circuit shake flashlight modified by David Johnson
Shake & Charge Flashlight

I bought one of the cheaper counterfeit devices and took it apart.  There were no manufacture or country of origin markings anywhere on the device.  I traced out the circuit.  It is not much more than a coil of wire, a magnet, a bridge rectifier, super capacitor and white LED.  A small magnet attached to an on/off switch is used to turn on the light by activating an internal reed relay.  This method maintains a tight weatherproof seal and is about the only thing I found cleaver about the device.  Shaking the thing forces a large magnet slug to slide back and forth inside the body of the device. Two rubber stoppers cushion the magnet at each end. In some other more expensive shake to charge flashlights, they use two more magnets as contact-less bumpers.
 Next Page >>



HOME Schematics Index Hobby Corner Dave's Circuits Electronic Resources Contact Info
Imagineering Ezine    Discover Solar Energy Dave Johnson & Associates Faraday Touch Switches


 About Us   |  Advertise on DiscoverCircuits.com   |   Report Broken Links  |    Link to DiscoverCircuits.com  |    Privacy Policy


Copyright  January, 1998 - November, 2017     David A. Johnson & Associates.  All Rights reserved. 


 Linking is ALLOWED but COPYING any content or graphics to your web site is EXPRESSLY PROHIBITED.