van der Pol Equation

An Ordinary Differential Equation which can be derived from the Rayleigh Differential Equation by differentiating and setting $y=y'$. It is an equation describing self-sustaining oscillations in which energy is fed into small oscillations and removed from large oscillations. This equation arises in the study of circuits containing vacuum tubes and is given by

$$y''-\mu(1-y^2)y'+y=0.$$

See also Rayleigh Differential Equation

References

Kreyszig, E. Advanced Engineering Mathematics, 6th ed. New York: Wiley, pp. 165-166, 1988.