Computerized circuit arrangement for jig saw

A circuit arrangement for an electrical jig saw of the type arranged such that a replaceable blade is driven by an electrical motor so as to move along a locus selected from a plurality of orbital modes, comprising:

• (a) first means for inputting information including the sort of the material of a workpiece to be cut, the thickness of the workpiece, desired degree of finish, and the way of cutting;
• (b) second means for computing and determining optimum working conditions including an optimum sort of blade, optimum blade strokes, optimum orbital mode, and information as to the necessity of application of coolant oil by using said inputting information;
• (c) third means for displaying inputting information from said first means and said optimum working conditions from said second means;
• (d) fourth means for detecting the rotational speed of said motor and producing an output signal indicative of the speed measured;
• (e) fifth means for producing a control signal by using said output signal from said fourth means and said optimum blade strokes from said second means;
• and
• (f) sixth means for controlling the rotational speed of the motor in accordance with said control signal.