NEMA 23 is a special-build stepper motor consisting of a 58.4×58.4-inch faceplate. It has a 1.8o step angle that can produce 200 steps per revolution. Each phase is capable of drawing 2.8 A of current with a voltage of 3.2V. It allows a holding torque of 19 kg-cm. This kind of motor is employed in the CNC machine, hard drives, and linear actuators. The motor consists of four wires of varying colors to distinguish them. They are terminated by bare leads. The green and black wires are connected to a single-coil while the blue and red wires are connected. This motor consists of four phases with 3.1 inches of motor length. There are four active lead spots and produces 3.6mH of inductance per phase.
As the NEMA 23 motor draws high current, one must control it using a powerful stepper motor device instead of controlling it through H-bridges. The motor can be rotated by energizing them in a logical order. By designing a digital logic circuit or by making use of a microcontroller, we can control the logical sequence.
Components of a motor and their description-
The copper wire windings are perfectly embedded into the stator and they are available in varying thickness and motor-specific inductance and resistance. Hybrid stepper motors are exclusively available with ball bearings. They determine the service life and are the only movable components of the motor. The shaft plays an integral part in the stepper motor. It is responsible for transferring kinetic energy. It is manufactured using non-magnetic, electrical stainless steel. The core of the rotor consists of a permanent magnet that forms the magnetic antipole to the respective electromagnet of the stator.
The small air gap in combination with the additional toothing between the stator and rotor implies a high torque and high positional accuracy. Toothing is achieved by punching soft metal plates forming the rotor body. Just like the rotor, the stator consists of soft-metal plates that are punched and electrically separated. Once the electromagnet in the stator receives the power, the arrangement of the stator and rotor teeth outcomes in a rotating movement.
The advantages of a stepper motor:
- The construction of this motor is very simple
- The motor does not slip or stall easily
- It possesses a high-reliability factor
- The response towards starting, reversing or stopping is excellent
- Produces accurate results as there are no contact brushes
- Produces maximum torque at low speeds and even at start-up
- The body of the stepper motor is rugged and prevents it from external damage
- The cost of control is minimum
- It is capable of operating in open-loop control system
- It’s suitable for working in any type of environment
- These motors are widely used in robotics
- The input pulse is proportional to the angle of rotation of the stepper motor
- Since the speed is proportional to the frequency, one can achieve various rotational speeds.