Electrostatic oscillators

Several types of electrostatic oscillators, with an electrically charged ball as the load, are examined, noting that a physical and a mathematical electrostatic pendulum together with a grounded conducting plate form a bistable oscillator for which the same set of parameters produces two stable and one unstable equilibrium positions. For this oscillator, bifurcation curves are drawn and nonlinear oscillations are studied. The electrostatic string pendulum also has a bifurcation point and, besides, can self-oscillate when electrically broken down. It is shown that a liquid–liquid interface placed in an external electric field can be regarded as an electrostatic oscillator. Experimental results confirming theoretical predictions are presented.