The word generator comes from the Latin generator and means "manufacturer". In general, a generator is a device, apparatus or machine that produces a product. Their functions also include the transformation of one type of energy into another.
In electrical engineering, a generator is a machine that generates electrical energy, i.e. converting mechanical energy into electrical energy. There are two types: DC generators and AC generators.
A DC generator is a rotating machine that consists of an armature, a stator and a collector-brush system and produces the DC voltage required to power the excitation systems of synchronous motors and generators in industry and power plants. Its best mode of operation is the self-excitation mode when operating with an electric machine exciter, which makes such machines more economical. Such generators are also used as a source of direct current for charging and recharging batteries, in DC electric welding (DCW), automobiles and aircraft.
An alternator is also a rotating machine and consists of a stator, rotor and excitation system. This synchronous machine generates an alternating electric current with a frequency of 50 or 60 Hz for the needs of the national economy in large power plants (hydroelectric power plants, state district power plants, nuclear power plants, thermal power plants, thermal power plants, etc.), as well as in portable power plants ("engines", ZhSK, "diesels" and etc.) and on ships.
In radio engineering and electronics, generators convert electrical energy into the energy of electromagnetic waves of a certain frequency. Therefore, they are briefly called frequency generators. Basically, there are two types: low frequency generators (LFO) and high frequency generators (HHF).
Low frequency oscillators generate audio frequency signals (from about zero to several hundred kHz), so they are also called audio frequency generators (AFG). Their other variety are pulse generators, which convert electrical energy into pulse energy that repeats at a certain frequency. LFOs with a wide spectrum of frequencies and harmonics are called multivibrators. All these generators are assembled from electronic devices (transistors, diodes, microcircuits). They are used in various areas of life as a signal source (electric bell, buzzer, metal detectors, cable detectors, measuring instruments, test signal generators, DC-to-AC converters, medical equipment, etc.). In addition, multivibrators are widely used in the manufacture of toys.
High-frequency generators are created on the same element base as LFO, but with the difference that they generate electromagnetic waves from hundreds of kHz to tens of GHz and piezoelectric elements (quartz resonators) are used to stabilize the frequency, as well as high-frequency varicaps (varicondas). These generators are used everywhere in radio transmitters, radio and television repeaters, at cellular and space communication stations, in mobile phones, radiotelephones, walkie-talkies, radars, flight control centers and medical equipment.
It should be noted that until recently, the element base of LFO and GHF was mainly based on vacuum tubes. Now vacuum tubes are almost completely replaced by transistors and microcircuits.
In industry, generators are also called plants that convert one substance into another. For example, an acetylene generator – for the production of acetylene from calcium carbide; steam generator, ice generator, gas generator – respectively for the production of steam, ice and gas.
In computer and computing engineering, individual programs or utilities are called generators. Key generators and code generators (keys, passwords), random number generators can be cited as an example.