What is the difference between a compressor and a generator?

Answer 1

In a generator, an armature is spun inside a magnetic field. The armature consists of several coils which generate electrical energy as they spin through the magnetic fields. "Brushes" (electrical devices to transfer the electrical energy from the moving armature) conduct the electrical energy to a wire. The strength of the electrical output can be controlled by varying the strength of the stationary magnetic field that is OUTSIDE the spinning armature. If that magnetic field is to be changed, it typically must be an electromagnetic.

An ALTERNATOR is exatly the opposite. The brushes make contact with two spinning rings. The rings are connected to coils, and when voltage is applied the armature (in the case of an alternator it is called a "rotor") becomes a spinning electromagnet. A stationary coil or set of coils, depending on the complexity of the armature, generates electrical current as the magnets pass by.

An alternator produces "alternating current" electricity which must be converted to "direct current" in the case of automobiles. The conversion is relatively simple, using what is called a "diode plate", which is as the name suggests, a collection of diodes.

Answer 2

An inverter generator typically has an engine that can be run at variable speed depending upon the load. The engine is connected to an efficient alternator whose output is converted to DC by a rectifier and smoothed somewhat by capacitors. This raw DC power is then inverted into smooth AC power of the proper frequency and voltage for the output (for example 110-120VAC 60HZ or 220-240VAC 50 or 60 HZ). Regulation is very good and the system will use less fuel if the load is small or variable since the control system will allow the engine to idle down when the load is small or throttle up when the load is large.

A standard "generator" or "genset" is an engine connected to an alternator and run at a speed that is some multiple of the desired AC frequency, regardless of the load on it (as the load increases the throttle opens more to keep the engine speed the same). The output of the alternator is connected directly to the load. Typical speeds are 1800 or 3600 rpm in the USA for 60HZ power when using a 4-pole or 2-pole alternator respectively. The engine speed control can be as simple as the mechanical feedback governor system used for any constant-speed engine.

Answer 3

There is no similarity between the two objects.