The frequency comb is generated by a laser that produces a series of veryshort, equally spaced pulses of light (like the teeth of a comb) across a broadspectrum of frequencies.

A sine wave alternating voltage signal is generated synchronously in the presence of gear teeth made of carbon steel, magnetic stainless steel, or iron (ferrous metal).

In small tooth difference of inner meshed transmission, there were a few pairs of tooth faces which were apart from each other for a small gap beside the contact point generated by two meshed teeth.