text: link to the electronic circuit design for control of oscillations in real life phenomena? can neone provide a link to a circuit which controls oscillations of a pendulum or an oscillator in real life?for example in a mechanical swing. not to a pendulum but to control oscillations in a circuit sense, on ecould use a phase lock loop (pll).  its whole life revolves around using a reference oscillator, locking onto it and outputting a new oscillation of frequency f or some multiplier of f. the major components are as follows 1) phase detector:  it determines if you are locked or not 2) charge pump: produces an up or down control signal depending on the output of the phase detector to either speed up or down f 3)voltage controlled oscillator (vco):  takes the up/down control signal from the charge pump and produces a new f that is either faster or slower.  this is the output of your new oscillator. 4)feedback loop: taken from the vco, it is compared with the reference oscillator you started with and determines if the two are locked.  if they are, you have a locked pll and can know that the output from the vco is a good clean clock.  this is a reeeeaaaallll basic overview.  some pll designer will probably come in and correct me!