What is rapping motor?

Rapping motor is a colloquial term for a vibrating electrical motor. The "rapping" sound it produces is caused by the rapid reciprocation of the armature. The motor consists of a coil of wire wound around a magnetic core, with a commutator that reverses the direction of current flow through the coil. This causes the armature to vibrate back and forth, producing the characteristic "rapping" sound.

Rapping motors are commonly used in small electrical appliances such as vibrators, massagers, and toothbrushes. They are also used in some industrial applications, such as air compressors and electric hammers.

The main advantage of rapping motors is their simple construction and low cost. However, they are also relatively inefficient and can produce a high level of noise.