Acta Phys. -Chim. Sin. ›› 2002, Vol. 18 ›› Issue (03): 218-222.doi: 10.3866/PKU.WHXB20020306

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The Time Delay Control of Current Oscillation of Potentiostatic Anodic Dissolution of Copper

Li Xue-Liang;Lu Dao-Yong;He Jian-Bo;Wang Hua-Lin   

  1. Institute of Applied Chemistry,Hefei University of Technology,Hefei 230009
  • Received:2001-09-19 Revised:2001-11-08 Published:2002-03-15
  • Contact: Li Xue-Liang

Abstract: The difference between the delayed out put signal and the output signal itself is used as a control signal,timedelayed control is applied to the course of copper anodic dissolution in phosphoric acid solution.The time of delay and the weight of the feedback are adjusted in the experiment; the influence of time delay and control strength on potentiostatic current oscillation of anodic dissolution of copper is studied.The periods and amplitudes of current oscillation are strongly dependent on the delay time and control weight.Time delay has an distinct effect on the frequency of current oscillation.This feedback performs the selfcontrol and selfadjust.Oscillation period is large at small time delay,but is small at large time delay.Time delay has a profound effect on waveform of current oscillations,and the increase of the control strength results in a bifurcation of current oscillations.Low control strength will tend to stabilize periodic orbits.With the increase of the control strength,the newly created periodic oscillation states increase, and mixedmode oscillations and these orbits can be stabilized.Under appropriate control conditions,period3 oscillations are found and can be stabilized.At higher feedback strengths,chaotic states appear.Simple integer proportions are exhibited and oscillations are controlled by the periods of inherent oscillation and the periods of delay time.The control mechanism and emergence of special oscillation are analyzed and discussed.

Key words: Copper, Anodic dissolution, Current oscillation, Chaos, Time delay control