Instructables

Make a tiny Dynamo flashlight from junk in 2 steps

Picture of Make a tiny Dynamo flashlight from junk in 2 steps
The power of junk! Here is something really cool to make out of a tape player/ or CD player and a LED.

Any old LED will work, but it will be a lot brighter if you can find some 5mm white ones. Pretty much all LEDs will run happily (and forever) on the low current supplied by a tape/CD player motor.

What makes this project really cool is that the end result is not just a demonstration of free power generation, it's also quite practical. The LED is blinding bright... I always keep one handy in case of a thermonuclear exchange induced power outage.

Here's a video. It was kinda hard to take a video while spinning it...Oh, and I find it easier to spin it towards me (more leverage or something).
 
 
Remove these adsRemove these ads by Signing Up

Step 1: Here's what you will need

Picture of Here's what you will need
Look in the free bin at yard sales... I was only able to find a tape player motor and a 5mm blue LED.

1. Small Electric motor from a CD player or Tape player. Larger motors will work WAY better, but tiny motors are easier to find in the junk pile.

2. Any LED. 5mm white ones are preferred because of the brightness, but little green or red indicator LEDs will work fine too.

3. It's totaly optional, but pliers would probably help a little.

Step 2: LED installation

Picture of LED installation
Twist the ends of the LED into little loops and wrap them around the leads on the motor. Give the motor a fast spin and enjoy the free light!

LEDs only work one way (light emitting DIODE), so if it wont light up, switch around the LEDs leads and try again.

I have made it around 17 years ago when I was in my high school.....but there is a problem I faced at that time

It produces a humming sound of rotation when ever I tried to run a audio tape

sgomes32 years ago
Cool. You probably need a zener diode if you want to use a capacitor. Great idea for a another project. I use this for an emergency, but it uses batteries, and we all it expires sooner or later. https://picasaweb.google.com/114139587529302221541/Misc#5650192742949431842
(removed by author or community request)
nepheron (author)  DELETED_jacques32 years ago
Use a magnetic DC motor.
Well, this is fun! Picture attached.
motor-led-generator.jpg
 could I use this to charge a capacitor to run the led

nepheron (author)  shanetill2544 years ago
 The trouble is: When you spin the motor, it charges the capacitor...then the capacitor drains into the motor...
I suppose you could use a capacitor if you had some sort of diode arrangement.
scratchr4 years ago
Nice instructable! I have done this before, now i use stepper motors. just stick an led into the plug. If it does not work, just try different pins. Steppers are great because they don't need to be spun fast. However use a diode to turn the ac to dc if used to power polarity sensitive devices.
GreenD4 years ago
hhehe, put a crank & a resistor on this and it's a pretty nifty idea.
Bitszu4 years ago
You could also  just throw a flywheel onto the gear end and have the spin last a few seconds more
nepheron (author)  Bitszu4 years ago
I tried that, but it makes it too hard to spin. The extra weight just won't spin fast enough.
ive got a gear motor when i spin it once (one revolution) it spins the actual motor about 10 times so i can do this very easy But my ones charging a battery
If you keep the gears that the motor was attached to inside the tape player, and put a handle on one of the larger gears, then you would get the motor to spin faster and you would get more power to the light. 

A capacitor may not charge properly with the motor, but a small rechargeable battery should work.
nepheron (author) 4 years ago
Yes I do, but they don't work for some reason. No power gets stored when I use this dynamo.
It probably is,  which is why the LED looks like it (quite quickly) fades out instead of just going out (I COULD be mistaken, but that is what it looks like to me).  Without a way to either limit the current from flowing out through the LED immediately after it is stored an the motor stops spinning, it will simply drain off....pretty much immediately.
 
nepheron (author) 4 years ago
Don't forget to rate this if you liked it!
Do you have a way to store the power like in a capacitor?
Pro

Get More Out of Instructables

Already have an Account?

close

PDF Downloads
As a Pro member, you will gain access to download any Instructable in the PDF format. You also have the ability to customize your PDF download.

Upgrade to Pro today!