Diodes are a very simple, common and effective type of semiconductor device. As an introduction do the diode, it is very important that you understand what we mean by “semiconductor”. A semiconductor lies in the middle of electrical conductivity. This means that they are less conductive than conductors and more conductive than non-conductors. This is typically achieved by the levels of impurities within them. Using these as a part of circuitry is a very common and useful strategy.

What Do They Do?

One of the most common uses for the diode is to convert alternating current (AC) into direct current (DC). Each diode is made up of a cathode and an anode, which both connect externally. When AC is being used, energy passes through the diode. In this situation, positive voltage is applied to the anode and negative voltage is applied to the cathode. If polarity is reversed, the diode will stop the electricity from flowing through, thereby only allowing the current to flow in a single direction.

Types of Diodes

  • Solid State – In the past, the tube diode was one of the most commonly used types of diodes in electronic devices. As technology has advanced, this older technology has been replaced with the solid-state diode. This type of diode is much smaller, more break resistant and longer lasting. Furthermore, they do not generate the same amount of heat that tubes do and require no filament and filament power.
  • LEDs – The type of diode that almost everybody has experienced first hand, whether they know it or not, is the LED. LED stands for “Light Emitting Diode”. Similar to solid-state diodes, current can only pass through an LED whenever the polarity is right. Whenever current passes through this unique type of diode, light is produced. Because these diodes are very small and require a very low amount of electricity to work, LEDs are now found in almost all of our small to large electronics.
  • Tubes – Tube diodes are one of the first kinds of diodes to be used in our electronic devices. This type of diode is made up of a vacuum tube containing a filament heater, as well as a separate power source for the filament itself. While some musicians prefer to play on amplifiers that utilize this type of diode, it is not commonly found in today’s electronics.
  • Specialty – Because of their presence in nearly all of our small to large electronic devices, semiconductor diodes come in all shapes and sizes. In order to solve problems presented by special circuits, variations such as the schottky laser, infrared, tunnel, zener, varactor and others have been developed. Each is highly specialized and designed to be used only in certain devices.

Diodes come in a large variety of shapes, sizes, forms and functions. Because of their usefulness and versatility, they have become commonplace in nearly every electronic device that we have in our homes, businesses and other places. They are absolutely essential to the technology that we enjoy every day.