Sewing machines used industrial society uses electricity as an energy source. Electric power received by the electric motor is converted into kinetic energy. Rotation of the electric motor will be forwarded to move the sewing machine through a series of power transmission, among others, with pulleys and belts. For students who are just learning to sew, the sewing speed problem becomes one of the factors that determine the outcome of stitches. Students who are not familiar with this high speed will find it difficult to produce a good stitch. This study wanted to know the results of setting the electric sewing machine motor with resistance measurement, voltage and current flowing in the electric motor sewing machine, as well as the motor rpm. The study was conducted on a flat bed sewing machine with a high speed electric motor. Speed setting is done with the circuit TRIAC and DIAC, the triac and diac components into one. The results showed setting a string of AC voltage using a triac and diac pairs can be used as a universal regulator of motor rotation speed on the flat bed sewing machine. The magnitude of the percentage increased in the speed of the voltage of 100 volts to 215 volts with an increase in speed by 53.07%. The greater the voltage is increased, the amount of flow is also greater, and conversely the smaller the voltage applied, the less the current flows, so the inrush current can be avoided.
Keywords: sewing machine, settings, TRIAC, DIAC.