An electric strapping tool has an electric motor (10) with an output shaft (12) coupled to a feed wheel (20) and a modulator circuit (40) coupled to a power input of the motor (10) for controlling strap tension. A magnet (14) is disposed on an end of the motor armature and offset from the rotation axis thereof, and a magnetic field detector (52) is disposed near the magnet (14) to detect rotation of the armature. The motor (10) rotates the feed wheel (20) and vibrates a welding jaw (80) when the shaft (12) rotates in one direction, and tool parameter adjustment potentiometers (70,72) are isolated from abuse by the tool user by corresponding control knobs coupled thereto.