DIY whistle
3D cube illusion
Throwing knifes
DIY tractor
Sometimes it is necessary to choose the electric motor of several fastest or the slowest, or just find out the rpm. I offer the easiest and sufficiently accurate way.
How to measure rpm
Recently I found in the Internet at a very cheap solution for etching circuit boards. To make it you need components which total cost not more than $0.5.
How to etch pcb cheap
I'm going to present you an interesting led flashlight that works on Faraday's law of electromagnetic induction. Just shake it - and it will recharge.
DIY led rechargeable torch
What can I say, I made a tiny radio transmitter to spy on somebody, I want to share the experience. It works perfectly
How to make a radio transmitter
Many of us are still have the old cassette tape record players that already has become useless. You do not even know that such a cassette recorder could be connected to a common mp3 player!
MP3 to tape recorder adapter