Single phase series motor with commutator and DC motor will cause serious electrical interference to TV and radio, so the interference of tilting system to radio shall be considered in the design of electric screwdriver. Measures such as shielding, symmetrical connection of exciter windings, setting of electrical filters, and connection of filters into △ shape are mainly adopted. If necessary, small inductance coils can also be connected in series at both ends of the motor armature.