Hand Crank Desktop Toyorch From Junk Around the House

About: I am a hobist with lots of hobies from carpentry to mechanics. There is hardly any thing that i am not interested in.

Last week I was scavenging through my son's toys. I found one with a geared dc motor.
Looked very promising. I designed a circuit to make a hand crank torch. So here it goes.

Step 1: Schematic

The circuit that I got used a capacitor to store the charge that was generated from cranking motor. But I stripped it to just glowing 2 LEDs. I did not find any capacitors or diodes in the circuits.

Step 2: The Housing

Measured the motor+gearbox dimensions and made a box with card paper to hold everything. The largest section of the gearbox was just under 2 inches. So I made the box as 2x2x2 inch.

Step 3: Finally

Now glued the LEDs and put everything together with glue. Now the box is a totally enclosed thing.
For the crank! I planned to make a handle but a flat piece of wood looked more promising. I will be drilling a hole (the size of a thumb so it can be cranked easily. The handle is attached to the axle with a little mseal putty and air dried.

So now If you crank it clock wise one LED glows and going other ways the other LED glows. I am planning to add the capacitor and the switch the next time I make a trip to the electronic store.

Also I am planning to paint it in funky colors so that my kid can play with it!



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    2 Discussions


    5 years ago on Introduction

    Aren't geared motors are pretty useful.
    If you add a full wave bridge rectifier, then turning it in either direction can light the LED's, if their polarity it the same.
    Also, instead of 2 LED's with opposite polarity, if you can get a 3-color(?) LED, then turning it in one direction, it'll will glow one color and turning it in the other direction will glow another color -- I forgot what the colors are, and I think AC will make it glow the third color.

    1 reply

    Reply 5 years ago on Introduction

    Wow! thanks for the advice. Actually I left electronics long time back! actually 3 years! since my kid is born. He is quite an explorer wanting everything! So I disposed everything including small parts and soldering irons. I planed to make it quite complex! cutting down to the circuits and re-cutting down to do it with whatever at hand. I guess I will put another ible making a very complex one using a stronger more durable box!