The basic principle of the motor of the cheap power tools motor is widely used in electric tools because of its high speed, small size, large power, large starting torque, and easy speed adjustment. The electrical principle is that the motor stator has two poles, and two brushes are used to change the direction of the current in the armature winding through the commutator. When operating in single-phase AC current, since the two stator excitation windings are connected in series with the armature windings, the stator current and the armature current are the same current, and the current and the fundamental magnetic flux are close to the same phase, causing the current and the magnetic flux to produce electromagnetic transitions. The direction of the moment remains unchanged, so that the motor can run stably and continuously.
Single-phase series motors can use single-phase power frequency AC current, and can also be used on DC or other frequency power supplies under the same rated voltage, and their power, speed and torque do not change significantly. Most single-phase series motors use thyristor phase shift
The method of speed regulation, but at low speed has the disadvantages of low torque and unstable operation. In order to improve the speed regulation performance, you can use
The method of current feedback or voltage feedback. Hand-held electric tools-generally combine the switch and speed control part into a body.
