Electronic Sewing Machines – These machines have a few more functions and capabilities than the mechanical sewing machine. Electronic circuit boards were added to electric powered machines back in the 70s. It opened up the opportunity for sewers to have more speed without sacrificing any important power and it also improved the bobbin and needle control as well. Some electric machines have a feature that allows them to automatically cut thread and adjust the tension and stitch length for certain projects. This is a big time saver for the sewer. Some electric models can also automatically sew buttonholes and all the sewer has to do us put the size and shape into the machine.