MAKE presents: The Inductor

The deceptively simple wire coil that proves incredibly useful in the world of electronics - the inductor's ability to store energy in an electromagnetic field is the key to making transformers, electromagnets, and many more components. It truly is an awesome device!

 

Weekend Projects - Solar Joule Bracelet

The Solar Joule Bracelet combines two separate projects, a solar battery and a "joule thief," to build a wearable circuit that powers an LED. Solar energy flows through the photodiodes, building up a supercapacitor, which essentially acts like a battery. This energy is then delivered to the joule thief, where oscillations eventually exceed the LED's forward voltage, making it light up. Once fully charged, these oscillations will occur so fast that the LED will appear continuously bright, visible even during daytime!

 Complete instructions

 

Inductor basics

The basics of how inductors work, a demo showing an inductor filtering out high frequency signals, a quick low pass LC filter, and a demo showing the magnetic field created around inductors.