The diodes can be used as rectifiers, signal limiters, voltage regulators, switches, signal modulators, signal mixers, signal demodulators and oscillators. The fundamental property of a diode is its tendency to drive the power in one direction.
A diode is an electronic component with two terminals that conduct the current mainly in one direction (asymmetric conductivity); has a low resistance (zero ideal) in one direction and a high resistance (ideally infinite) in the other. A semiconductor diode, the most common one today, is a piece of crystalline semiconductor material with a p-n junction connected to two electrical terminals. A vacuum tubular diode has two electrodes, a plate (anode) and a heated cathode. Semiconductor diodes were the first semiconductor electronic devices. The discovery of crystallising abilities was made by the German physicist Ferdinand Braun in 1874. The first semiconductor diodes, called basic cat diodes, developed around 1906, were made of mineral crystals such as galena. Today, most diodes are made of silicon, but other materials such as selenium and germanium are sometimes used.
While only two semiconductor pin devices, there are a number of diode applications that are vital in modern electronics. The diodes are known only to allow the current to travel in one direction through the component.
This allows a diode to act as a one-way valve, maintaining the signals where it should be or pointing around the components. While the diodes leave the current movement in one direction, each diode acts differently, creating a number of useful diode applications.
Some of the typical diode applications include:
- Correcting a voltage, how to convert the alternating current into DC voltages
- Isolation of signals from a power supply
- Voltage reference
- Check the size of a signal
- Mixing signals
- Detection signals
- Laser diodes