- Electricity is transported through power lines alternating current (AC). AC electricity switches directions continuously, going from positive to negative and back again. Most electronic devices require direct current (DC) electricity, meaning the electricity always flows in the same direction. A rectifier is a device that turns AC into DC. Half-wave rectifiers are the simplest devices that perform this function.
- The AC power is first put through a transformer. A transformer consists of two coils of wire sitting right next to each other. When AC electricity moves through the first coil, it creates a moving magnetic field that encompasses the coil as well. This field produces an electric current in the second coil. Transformers are use to isolate the output current being rectified from the input current. They can also be used to change the voltage of the output current.
- The diode is the most important element in a half-wave rectifier. A diode is an electronic one-way valve; it allows electricity to flow in one direction, but stops it from flowing in the other direction. A half-wave rectifier uses a single diode to rectify half the wave of the AC current. When the AC flows in the positive direction, the diode lets it through, but when it flows in the negative direction, the diode stops it from flowing at all.
