Abstract: A control system for a sewing machine includes at least an impulse generating circuit and a counter means connected thereto. A shift register having at least four bits and a mode selecting circuit connected thereto is provided. A circuit for feeding the work material or fabric forwards, a circuit for feeding the work material backwards, and a circuit for resetting these circuits are provided. The system is:(1) capable of selecting, in advance, the number of stitches in a single forward and backward reciprocal non-ravel seaming;(2) capable of doing a desired number of the repeated non-ravel seaming on a certain place (repeated reciprocal non-ravel seaming mode); and(3) capable of free selecting between the conventional non-ravel seaming mode and the above-mentioned repeated non-ravel seaming mode (the free mode selection).

Abstract: An improved speed controlling system for an electric motor, mainly used in a sewing machine includes a motor connected to a power supply, a speed controlling circuit or circuits for operating the motor at variably controlled speeds, and an electrical braking circuit or circuits for braking the motor upon receiving deceleration command from the speed controlling circuit(s) to transfer the motor from a high speed running state to a low speed running one. Electromechanical braking means are provided for acting on the motor, during at least a part of the braking period, the braking means being controlled by the electrical braking circuit(s). A low speed setting circuit is disposed in the speed controlling circuit(s) for maintaining the low speed running state caused by the electromechanical braking means and the electrical braking circuit(s).