Emergency spin-it LED flashlight

Introduction

In emergency a small light source is a must. You may need it to find a more reliable light source like an operational flashlight. This flashlight is built around a super capacitor and a DC motor. Super caps can store up energy fast and release it slowly. These features plus their compactness make them so useful to build emergency flashlights. One can say: Hey, there are quite a few “shake-it” and “pump-it” models available at reasonable prices. That’s true, but my flashlight is a bit different. 1- minute finger spinning gives 5-minute lighting. You may opt to charge this flashlight with a string loop.
Time:  1 hour
Cost: low
Difficulty: easy

Step 1: Materials and Tools

Materials and Tools

You need:
1. A small plastic bottle. Mine is a container for vitamin C pills. It is large enough to accommodate a DC motor and other parts.
2. DC motor. Mine is a 9V motor salvaged from an old cassette recorder.
3. a short length of insulated wire.
Electronic parts: 1 super capacitor (1F/5.5V), 1 super bright 5mm white LED(50cd), 1 – 24 Ohm/0,25W  resistor (red-yellow-black), 1 Schottky diode (1N5819), a micro slide switch (3-pin).

Tools:

Wire cutters
Tweezers
Soldering iron
Drill and drill bits (optional)
Solder

Comments

[wgsinc]

"Look ma, No Batteries"... This is my kind of Instructable. Simple with few components.
Make a few of these -and you may be all set for the Myan cataclysm of Dec 21, 2012, if there is a major black-out .
"Supercapacitors" are the batteries of the near future.
(Good work, kostya - but the circuit you drew is not quite correct.
The diode is "blocking" the current from the motor.
Suggest you draw the diode 'ACROSS" the motor with reverse polarity to the motor.
That will protect it and allow the Supercap to be charged also.

[kostya]

Supercapacitors are still pricey here. Thanks for your suggestion.

[thangtran1024]

Check the direction of the diode!!!

[kostya]

I've just opened up the flashlight and checked. You are right. The Schottky is soldered with the cathode to the motor. Thank you!

[kostya]

I've just opened up the flashlight and checked. You are right. The Schottky is soldered with the cathode to the motor. Thank you!

[kostya]

I've just opened up the flashlight and checked. You are right. The Schottky is soldered with the cathode to the motor. Thank you!

[amandaghassaei]

this project is awesome! great idea for emergencies

[kostya]

Thank you! Vote, please!

[wannabemadsci]

A Really neat idea! Thanks for sharing!

An interesting modification would be to have the motor output go to a bridge rectifier (the AC input terminals) so that it can charge the supercap regardless of the direction it is spinning.

One concern: What if you spin your motor fast enough to generate over 5.5V? I think your super cap may not last long. ;-)

[kostya]

Thanks! I have got an idea to build another flashlight with AC input, but there will be no DC motor at all. Your can rectify AC voltage with a simple circuitry and charge a super capacitor. As for your concern, I am in a great doubt that somebody is able to spin the motor so fast to overrate 5V. I checked with the multimeter and it showed 3V at most.