Armature circuit in electric tool and battery pack socket

The invention discloses an armature circuit in an electric tool, which comprises a power supply and a motor. Two electrodes of the power supply are respectively provided with connection structures connected with an output part. One connection structure is a multi-contact on/off controllable movable contact structure and the other is a double-faced multi-contact structure. The invention also discloses a power socket for the electric tool by adopting the armature circuit. Internal resistance of the motor armature circuit is greatly reduced, hardness of motor running characteristics is enhanced, and the working efficiency of the tool is improved; due to decreasing of the internal resistance, current loss of the armature circuit is reduced, and temperature rise of an electric appliance and contacts is reduced; and in the same working efficiency condition, by adopting the technology of the invention, battery capacity can be saved, and the battery cost is reduced.