How To Create a Rechargable LED Flashlight

Using electromagnets, a small-scale LED flashlight similar to that featured in "Shake It Like a Tic-Tac!" can be produced.

With the setup for the Tic-Tac flashlight, the voltage produced by the magnet alone may not be enough to power up the LED. It is possible that the only reason the LED lit up was due to the rechargable battery not being completely empty in the first place. This theoretical experiment attempts to improve on the circuit based on one of the comments made on "Shake it like a Tic-Tac!"

Image taken from Shake it like a Tic-Tac! page.

Step 1 Parts Needed

1N4148 signal diodes x 2
Magnet 20 mm in Diameter x 1
470u Electrolytics x 2
White LED x 1
Magnet Wire x 300 ft

Ballpen case or some hollow cylindrical tube that can fit the magnets and accommodate the coils of wire
Pliers
Sandpaper

Comments

[rohanpsp]

i have made a tic tac which uses joule thief which increases output freuency led lasting for more than 4 mins recharging in 5 shakes.

[johnrein]

sir i wanna some flying mini project so please send me

[eyerobot]

This circuit requires constant shaking to work.  I dont know about others, but I cant see anything with the light bouncing continuously. And before you ask, Yes I did build it!

The problem with it, Is that it doesnt store enough power, To enable it to charge the LED for any length of time.

It also doesnt have overcharge protection for the capacitors, And could burn out the capacitors quickly with too much shaking, Such as running with it in your pocket.

I know simplicity is important, And could get you points in a presentation of some sort, But for practical uses, It needs to be made completely safe for end users.

Anyway, I'm adapting this project to suit my needs, By creating a rotary generator, That is powered by a pendulum contained within its case.

The capacitors will be significantly larger, So it will hold a charge for a long period of time.

And it will have a charge limiter, To make sure the capacitors cant overload, And explode.

The design that I am working on is to be worn on your belt with a clip, And uses the natural swinging motion of the human body to activate the pendulum.

I know its been done before, But as I said, This is something that I can personally use, And I dont have the money to throw away on luxuries like this.

This project here, is most definitely not the authors invention.
I have read this before, With a lot more detail, In various books i've read.
Also this author has zero comments on this site.

[Asbestos]

What do you mean by "What is important to consider is that the coil should be larger than the diameter of the wire in order for the maximum voltage to be generated." If you mean the total size of the coil, well... naturally the coil is going to be larger than the diameter of the wire. The diameter of the wire is tiny. Do you mean the thickness of the edges of the coil, maybe? Should the wire be wound back over on top of itself?

[joshuamjones]

i agree, because in that case, if you went two times around, you would already be larger than the diameter of the wire. or does this have to do with the spacing of the wire maybe, but then again, that wouldn't make sense.

[hesperaux]

I, too, do not understand what you meant by that statement. I read it several times. =S I'm assuming the same thing Asbestos is: that the thickness of the coil should be more than the thickness of a single wire (in other words, a short coil with multiple layers instead of a long coil with one layer).

[BuckyOHare]

"Basically, the magnet in the set-up will pass through two coils in order to increase the generated current. Each coil should be composed of winding the 20mm wire 600 times." "What is important to consider is that the coil should be larger than the diameter of the wire in order for the maximum voltage to be generated." "The coils actually sit flat against the slide (against the side of the magnet) as shown in the diagram below. " WHAT? Explain please. You have one picture of winding wire round a paper tube, this is not helpful. The LED testing picture isn't helpful or necessary. How do the coils sit flat against the side, yet are wound around a tube? How does the magnet fully pass through the coil when it is wound very near to the end of the tube? What does the coil(s) look like after winding is complete? Where is the end product? This instructable is confusing.

[sheechiibii09]

Oh! thank you for clearing things up about the circuitry of the thing. It was hard to imagine how the parts go together from a drawing on a piece of paper. It was a big help, thanks!

[evildoctorbluetooth]

thats a differenct circuit from the original, so shouldnt be used as a guide/

[Havoc481]

does this one actually work because the last one posted was a piece of trash I tried to make for my high school science project and it never worked

[Corpy]

Woot That's One awesome project... I try made something like that too...xD

[Zorink]

Instead of a straight cylinder (step 2 and 3), would a hollow toroid work better? Rather than stopping at the bottom, the magnet would continue moving around the circle, so more motion = more electricity?

[chinmoy1955]

A hollow toroid? Ya, a good idea technically, but very difficult to construct physically at home. To wind a toroidal coil, you require special equipment. Moreover, a magnet kept inside the toroid cannot be made to spin or rotate easily, it needs to be mounted on a spindle or some sort of a bearing, which further complicates matter. In short, it is not a workable idea.

[Smokedasphalt]

spinning d magnet in a hollow toroid wouldn't be easy! and u would even need a spherical magnet for that.

[brunoip]

would it work with a ni-cad battery ?

[awang8]

Uhh... Yeah, I know it got featured, but have you even made this? There are hardly any photos!

[madmanmoe64]

Whilst the circuit diagram Colin drew up looks sound, neither he or the maker of this instructable have bothered to build it and see if it works. Has anyone actually tried this? Normally that'd put me off but I'm tempted to build one and post my own instructable proving if it can be done.

[brodyf]

why does this feel like plagiarism to me?

[akimbo m]

because there was a previous tick tac shake light done before..
http://www.instructables.com/id/Shake-it-like-a-Tic-Tac!/

However this one does have one design difference which i think makes it better...

if i can remember... the difference is in the design of the capacitor... basically in this one... he uses the quirk of the capacitor having a polarity... and thus aligning it in a diode bridge formation... to eliminate two diodes.

I think that's a pretty good idea... as it makes this cheaper and more compact to build.

[hg341]

i dont think you made this...

[lemonie]

Have you actually built this?
(doesn't look like you have)

L

[Mikey D]

I teach HS electronics and had the low V problem with making the tic tac lights. this would help if I could understand how the coil (coils?) mount in relation to the magnet tube. A picture (several close ups) of the finished product would help immensely! The last pict just looks like an LED Throwie.

[flock]

this sounds easy and fun. i'll try making it for my extra cred project. thanks for posting!

[maxone76]

Man! What are you talking about clearing things up? You've got 5 steps from the 9 in the original! Tha't not clearing things up! And some instructions were also vague, it seems to jump from one procedure from another.