TIGHTENING TORQUE ADJUSTING CIRCUIT

摘要

PURPOSE: To keep tightening torque constant for each screw when the screw is tightened by a screw tightening electric tool. CONSTITUTION: A tightening torque adjusting circuit of a screw tightening electric tool is provided with a rotation detecting part 6 to detect the number of rotations of a rotating part RG, and a timer part 7 having a one-shot multi-vibrator IC2 to control a driving part 8 so that a motor 4 is stopped after the preset period of time from the timing when the number of rotation of the rotating part RG is reduced to the prescribed value in the condition when the tightening of the screw is almost completed.