ABSTRACT
This chapter discusses some classical schemes of oscillators. It highlights that: oscillations are generated through Hopf bifurcation, a negative resistance has to be included in the circuit to obtain oscillations and describing function approach can be used to design oscillators. It discusses 2D discrete-time maps showing that, contrary to second-order continuous-time autonomous systems, their behavior can also be chaotic. The chapter discusses that in one-dimensional maps, oscillations, including complex ones, can be generated with only one state variable. On the contrary, to obtain oscillations in a continuous-time system, at least two state variables are needed. The chapter introduces from simple to complex systems, providing the essential concepts in a self-contained reference, discusses the main notions on electronic oscillators. It starts by considering some ideal oscillators: the lossless LC electrical oscillator, the spring mass oscillator without friction, and the mechanical pendulum, that is equivalent to the spring mass oscillator in the case of small perturbations.
