Stepper motors are discrete motion devices that have an essential connection to modern digital control technology. In the current domestic digital control system, stepper motors are widely used. With the advent of all-digital AC servo systems, AC servo motors are also increasingly used in digital control systems. In order to adapt to the development trend of digital control, most of the motion control systems use stepper motors or all-digital AC servo motors as the execution motors. Although both are similar in control (pulse train and direction signal), there is a big difference in performance and application.
Stepping motors are mainly classified according to the number of phases, and two-phase and five-phase stepping motors are widely used in the current market. The two-phase stepper motor can be divided into 400 equal divisions per revolution, and five phases can be divided into 1000 equal divisions. Therefore, the characteristics exhibited are preferably five-phase stepping motor, shorter acceleration/deceleration time, and lower dynamic inertia. . This article describes in detail what is the difference between a two-phase stepper motor and a five-phase stepper motor.
Two-phase stepper motor as an actuator is one of the key products of electromechanical integration and is widely used in various automatic control systems. With the development of microelectronics and computer technology, the demand for stepper motors is increasing day by day, and there are applications in various national economic fields.
A two-phase stepper motor is an actuator that converts electrical pulses into angular displacements. It is generally said that when the step driver receives a pulse signal, it drives the stepper motor to rotate in a fixed direction (ie, a step angle) in a set direction. By controlling the number of pulses to control the amount of angular displacement, so as to achieve the purpose of accurate positioning; at the same time can control the pulse frequency to control the speed and acceleration of the motor rotation, so as to achieve the purpose of speed control.
Two-phase stepping motors are often used in digital control systems, with high accuracy and reliable operation. If using position detection and speed feedback, closed-loop control can also be achieved. Stepper motors are now widely used in digital control systems, such as digital-to-analog converters, CNC machine tools, computer peripherals, automatic recorders, clocks, etc., as well as applications in industrial automation production lines and printing equipment.
The difference between two-phase stepper motor and five-phase stepper motor
First, the control accuracy is different
The step angle of the two-phase hybrid stepping motor is generally 3.6° and 1.8°. The step angle of the five-phase hybrid stepping motor is generally 0.72° and 0.36°. There are also some high performance stepper motors with smaller step angles. For example, a step motor manufactured by Stone Company for use in a slow-moving wire machine has a step angle of 0.09°. The step angle of the three-phase hybrid stepper motor produced by BERGER LAHR in Germany can be passed. DIP switches are set to 1.8°, 0.9°, 0.72°, 0.36°, 0.18°, 0.09°, 0.072°, 0.036° and are compatible with step angles of two-phase and five-phase hybrid stepper motors.
AC servo motor control accuracy is guaranteed by a rotary encoder at the rear end of the motor shaft. Taking Panasonic's all-digital AC servo motor as an example, for a motor with a standard 2500 line encoder, the pulse equivalent is 360°/10000=0.036° due to the quadruple frequency technology inside the driver. For a motor with a 17-bit encoder, the driver receives one revolution of 217=131,072 pulses per pulse, ie, its pulse equivalent is 360°/131072=9.89 seconds. It is 1/655 of the pulse equivalent of a stepping motor with a step angle of 1.8°.
Second, different low-frequency characteristics
Stepper motors are prone to low frequency vibration at low speeds. The vibration frequency is related to load conditions and driver performance. It is generally believed that the vibration frequency is half of the motor's no-load take-off frequency. This kind of low frequency vibration, which is determined by the working principle of the stepper motor, is very unfavorable to the normal operation of the machine. When the stepper motor operates at a low speed, damping techniques are generally used to overcome the low-frequency vibration phenomena, such as adding a damper to the motor, or using a subdivision technique on the driver. The AC servo motor operates very smoothly and does not vibrate even at low speeds. The AC servo system has a resonance suppression function that can cover the lack of mechanical rigidity, and the system has a frequency analysis function (FFT), which can detect the mechanical resonance point and facilitate system adjustment.
Third, different characteristics of the moment frequency
The output torque of the stepping motor decreases with the increase of the rotational speed, and drops sharply at higher rotational speeds, so the maximum operating rotational speed is generally 300-600 RPM. The AC servo motor is constant torque output, that is, it can output rated torque within its rated speed (generally 2000RPM or 3000RPM), and it is constant power output above the rated speed.
Fourth, different overload capacity
Stepper motors generally do not have overload capabilities. AC servo motor has strong overload capability. Take Panasonic AC servo system as an example, it has speed overload and torque overload capability. Its maximum torque is three times the rated torque and can be used to overcome the moment of inertia of the inertial load at the moment of starting. Because there is no such overload ability for the stepping motor, in order to overcome this kind of moment of inertia during selection, it is often necessary to select a motor with a relatively large torque, and when the machine does not require such large torque during normal operation, a torque occurs. Wasted phenomenon.
Fifth, different operating performance
The control of stepping motor is open-loop control. If the starting frequency is too high or the load is too large, it is easy to lose the steps or stall. When the speed is too high, the overshoot may occur. Therefore, in order to ensure the control accuracy, it should be handled well. Increase or decrease speed. The AC servo drive system is closed-loop control. The drive can directly sample the feedback signal of the motor encoder. The position loop and the speed loop are internally formed. Generally, there is no phenomenon of stepping motor overshoot or overshoot, and the control performance is even better. .
Sixth, different speed response performance
It takes 200-400 milliseconds for a stepper motor to accelerate from rest to operating speed (typically several hundred revolutions per minute). Acceleration performance of AC servo system is better. Taking Panasonic MSMA 400W AC servo motor as an example, it only takes a few milliseconds to accelerate from standstill to its rated speed of 3000RPM. It can be used in control applications requiring fast start-stop.
The number of phases of a stepper motor refers to the number of coils in the motor. Currently, there are two-phase, three-phase, four-phase, and five-phase stepper motors. The number of phases of the motor is different, and the step angle is also different. Generally, the step angle of the two-phase motor is 1.8 degrees, the three-phase is 1.5 degrees, and the five-phase is 0.72 degrees. When not subdividing the driver, the user mainly selects the stepper motor with different number of phases to meet the requirement of the step angle. If you use a subdivision driver, the number of phases will become meaningless, and the user can change the step angle by simply changing the number of subdivisions on the driver.
The N-phase stepper motor has N windings. The N windings must be evenly embedded in the stator. Therefore, the number of magnetic poles of the stator must be an integral multiple of N. Therefore, the number of steps of the rotor's turn should be an integer multiple of N; That is to say, the number of steps of a three-phase stepping motor is one integer multiple of three. The number of steps of a four-phase stepping motor is one integer multiple of four. The number of steps of a five-phase stepping motor is one revolution. An integer multiple of 5; if the basic step angle of the stepper motor is θ, the number of steps in one revolution is M, and the number of phases of the stepping motor is N, there is the following relation: θ=360/M due to the above-mentioned mechanical symmetry principle M must be an integer multiple of the number N of phases. According to the above analysis, it can be seen that the basic step angle cannot take any value.
There is no necessary connection between the wiring and the number of phases outside the stepper motor. It is determined based on the actual application needs.
For example, eight lead-out two-phase/four-phase motors can be connected to four-wire two-phase motors according to the requirements, and can also be connected in five-wire or six-wire four-phase motors.
There are six lead wires that can be either 3-phase motors, 2/4-phase motors, or 5-phase motors. The multimeter is placed on the X1 block, 1. The three-phase motor can be divided into three independent windings; 2. If the three heads are connected and the other three heads are disconnected, it is a 2/4 phase stepper motor; It is a 5-phase stepper motor, 5 lines correspond to 5 phases, and the other is the common terminal.
1. Two-phase motor: Lead wires can be four or eight.
2. Four-phase motor: Lead wires can be 5, 6 or 8.
3, three-phase motor: lead wire can be 3 or 6.
4. Five-phase motor: Lead wires can be 5, 6 or 10.
talking bottle opener (Music Bottle opener)
Ningbo AST Industry Co.,Ltd has 17 Years Experiences to produce the Voice Bottle Opener,Musical Win Opener,Talking Bottle Openers and so on.we can assure you of competive price,high quality,prompt delivery and technology supporting.
1. Music Bottle opener Application:
The Voice Keychains are usually used for Celebration,Promotion,Birthday,Holiday,Award Ceremony,Party and so on.Open the bottle ,it will play the music or recorded message or advertising language.
2. Music Bottle opener Classification:
There are Recordable Bottle opener and Musical bottle opener
Recordable Bottle Opener
the Clients can record our own message and playback it .
Recording time:6s,10s,20s etc.
Music Bottle Opener
The audios will be customized.The clients provide the audios,the we programme the audio into the opener ,then it will play the customized audio when we open the Bottle.
  |
|
3. Sound Quality:Clearly and Loudly
4. Play activated:Open the bottle to play the message automatically
5. Can be printed your logo on it
6. Certification:CE ,Rohs
7. Export to:
Talking Bottle Opener, Musical Bottle Opener, Talking Beer Bottle Opener,Bottle opener
AST Industry Co.,LTD , https://www.astsoundchip.com