Examples of self-oscillatory systems with lumped parameters. I

Abstract

Vacuum tube generators are classical examples of self-oscillatory systems which in certain simple cases can be described by the van der Pol equation or by the Rayleigh equation. These are precisely the systems which have been studied in the first works of van der Pol [Van der Pol, 1920, 1960] . In more recent times vacuum tubes changed to transistors, but in essence the operation of these electronic generators has remained the same. The block diagram of a vacuum tube (or transistorized) generator is presented in Fig 16.1. An oscillatory circuit is connected to the input of a non-linear amplifier. The amplifier output signal, in its turn, causes an e.m.f. of induction in the circuit. The vacuum tube generator differs from the transistorized generator only in its active elements (vacuum tubes or transistors) for the amplifier. Open image in new window Fig. 16.1 The block diagram of a vacuum tube (or transistorized) generator.