Peculiarities of dynamical control in a open loop system with the boundary layer by means of periodical generation of microbubbles of flow around cylinder are presented. Experiments were carried out in the range Re = (0,3−1,2)105. It is shown that at this method the results remain the same as in the case of continuous microbubbles generation but energy consumption is two times smaller. Results can be accounted for delayed reaction of boundary layer separation on perturbances stopping. Lock-in modes of shedding separation frequency fN and frequency of forced oscillations fE and imposition of these frequencies are discovered. Maximum values of amplitude of resistance oscillation and lift are located in the range of low frequencies (fE/fN <0,07).