CONTROL OF FREQUENCY OF REVOLUTION OF STITCHER DRIVE Russian patent published in 1995 - IPC

FIELD: sewing mechanical engineering. SUBSTANCE: frequency control of sewing machine has differentiating circuit 2, integrator 3, comparator 4, brake pulse former which has RC-circuit and Schmitt flip-flop 7. Revolution frequency pulse detector 1, differentiating circuit 2 and integrator 3 are connected together, as a result, pulsing voltage is formed at output of integrator 3; constant component of the pulsing voltage is proportional to frequency of revolution. Break pulse former operates in this case only when frequency of revolution changes from high level to lower one being close to signals from output of comparator, which is equal to zero at this mode in comparison with high level at start mode. EFFECT: reduced number of members of the circuit; improved dynamic characteristics; reduced amount of software. 1 dwg