Forcing of Oscillations

a phenomenon that occurs during the action of a periodic external force on a system that is performing self-oscillations (electrical, mechanical, or other types); it consists in the fact that the frequency of the free oscillations becomes equal to that of the external influence or to a value that is an integral number of times greater than the frequency. Forcing of oscillations occurs whenever the frequency of the external influence is close to the natural frequency or to a frequency that is an integral number of times smaller, if the amplitude of the external force is sufficiently high. The phenomenon is also called forced or external synchronization.