A rectifier diode is an electronic device designed to convert AC current into DC current. This is such a two-electrode device that has only one-sided (unipolar) electrical conductivity. The rectifier diode made of semiconductor materials and the so-called diode bridges (when four diodes are connected diagonally in pairs in one package) replaced the ignitron and the vacuum diode.
The effect of rectifying alternating current and converting it to direct current occurs at the semiconductor-metal, metal-semiconductor junction, or in the so-called electron-hole junction in some crystals (for example, silicon, germanium, selenium, cuprous oxide). Such crystals often serve as the basis of the device.
A semiconductor rectifier diode is used in radio engineering, in electronic and electrical devices. In essence, rectification is the transformation of current alternating (voltage) into a current of one polarity (pulsating direct). This type of rectification in technology is necessary for opening and closing electrical circuits, switching and detecting electrical signals and impulses, and for many other similar transformations. Such characteristics of the diode as speed, stability of parameters, capacitance of p-n junctions do not require any special requirements.
Such a device has certain electrical parameters and diode characteristics:
- forward voltage at the specified current value (average value is taken);
- reverse current at a given value of reverse voltage and temperature (average value);
- peak allowable values for maximum reverse voltage;
- average value of forward current;
- frequency value without mode reduction;
- resistance.
A rectifier diode is often abbreviated as just a rectifier. As a component of an electrical circuit, it offers high resistance to current flowing in one direction and low resistance to current flowing in the opposite direction. This causes the current to be rectified.
A device such as a rectifier diode has a fairly small frequency range. The operating frequency for industrial use of such a device when converting AC to DC is 50 Hz. The limiting frequency is considered to be no more than 20 kHz.
The rectifier diode as an electronic device can be divided into several groups according to the value of the maximum average forward current. This is a low power diode (up to 0.3 amps), medium power (from 0.3 A to 10 A) and heavy duty (power) rectifier diodes (more than ten amps).
The main parameters of such an electronic device as a rectifier diode, it is necessary to include the operating range for the ambient temperature (usually it ranges from -50 to +130 degrees Celsius for the most common type of diode - silicon) and the maximum case temperature (a variety of parameters, depending on power, purpose and manufacturer).
