Inverter generators are a recent technology, made possible by advanced electronic circuitry and state-of-the-art magnets. The technology generally outputs AC current like most conventional generators, but the current is then converted to DC voltage, and then “inverted” back to clean AC voltage, thus how it gets its name. The advantage to this inversion, is that it maintains a constant flow of current to your appliance.
Conventional generators are the most widely used today, also because they have been around the longest. How they work has remained essentially unchanged. They run on diesel, gasoline or (our choice) propane/lpg, which in simple terms, powers a motor attached to an alternator that produces electricity. The generator’s motor runs at a constant speed (usually 3600 rpm) to produce the required electrical current (in the U.S., typically 120 Volts AC / 60 Hertz, and in most other countries, 240 volts AC / 60 Hz). The engine’s rpm should not fluctuate, otherwise it will alter the frequency (Hertz) of electrical output.