LED polarity

On the positive side of LED: a thin wire inside of the bulb, a bump on the side of the bulb and a long pin. 

On the negative side of LED: a thick wire inside of the bulb and a short pin.

3.5mm Audio Splitter DIY

I have made a 3.5mm audio splitter in one of the previously published instructions.

Audio splitter DIY. How to make 3.5 mm earphone or headphone audio splitter

Often I want to watch with my son something on my laptop, smart phone or tablet. 

Usually, such  devices have only one plug for earphones! 

It's curable with 3.5 mm audio splitter.

How to find corresponding ends of wires

We can use broken earphone cables for many DIY home projects.

 In this instruction I explain to my 6 years old son how to find corresponding ends of wires in the cable using simple flashlight as a tester.