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Contactor is an automatic electromagnetic switch for long-distance frequently connected or disconnected AC and DC main circuit and high-capacity control circuit. The main control object of a contactor is the motor, it can be used to control other loads as well.
According to the current types that through the main contacts, contactor is divided into AC contactor and DC contactor. The structure and working principle of both are basically the same, which mainly consists of three parts, electromagnetic mechanism, contact system and arc-extinguishing equipment. In the electrical control circuit of machine tool, AC contactor is mainly used. This article focuses on the basic structure of the AC contactor.

When switching power supply blows a fuse, when there is no DC output or volatge output is unstable, when switching power supply has poor load capacity, how to do? Click it and then you will know how to deal with these problems as well as some repairing skills.

DC contactor is mainly used for remotely connecting and disconnecting the DC circuit, as well as frequently starting, stopping, reversing and plug braking the DC motors. It's also widely used for connecting and disconnecting the lifting electromagnet, solenoid valve, clutch's magnetic coils. DC contactor has two structure of stereoscopic arrangement and plane arrangement, some products are derived on the basis of AC contactor. Therefore, structure and working principle of the DC contactor are basically the same as that of AC contactor, which mainly consists of three parts, electromagnetic mechanism, contact system and arc-extinguishing equipment.

A contactor is mainly used in a primary loop, which can go through a large current (several hundred to about one thousand Amps). While a relay is used in a secondary circuit to achieve various control functions, which can only go through a small current (several to decades Amps). Functions, contacts opening and closing situation of the two subject are different.

Power line filter is electrical equipment which effectively filters particular frequency point in the power line or the frequency out of the particular frequency point. It is a passive bi-directional network, that is, one end is power supply, and the other end is load. When selecting an EMI power line filter, what should be taken into considerations? Rated voltage, rated current, insertion loss...

What is a power line filter? What does a power line filter do? A power line filter, also called EMI power line filter, is a passive bi-directional network, electrical equipment which effectively filters the particular frequency point in the power line or the frequency out of the particular frequency point. Power line filter is to get a certain frequency power supply signal or the power supply signal after eliminating a certain frequency through connecting power supply filter in power line...

How to select a right solid state relay? When selecting solid state relay(SSR), it should be based on the actual application conditions and SSR performance parameters, and especially take into consideration the overcurrent and overvoltage conditions in the use and the load capacity of SSR, which is helpful to achieve the long life time and high reliability of solid state relays. Then, follow the questions and find the detailed answers to choosing a right  SSR.

What is a solid state relay(SSR)? A solid state relay is a non-contact switch fully composed of solid state electrical-element, which can drive high-current load with a small control signal. It can achieve switching on and off with no contact and no spark due to the switching characteristics of electrical element (i.e. semiconductor components like switch transistor, triac and so on). Solid state relay has such following advantages over electromagnetic relays: high reliability, no contact, no spark, long life, fast switching speed, strong anti-interference ability, and small size.

Solid state relay (SSR) is a non-contact switch composed of solid-state electronic components with high reliability, non-contact, no spark, long life, no noise, no electromagnetic interference, high switching speed. Electromechanical relays (EMR) is a kind of magnetic switch made up of multi-coils, movable elements, contact system etc. and it is easy to drive and widely used in all the areas. Then what are they differences? Which one is better?

What is a servo motor? Servo motor is the motor which controls mechanical components operation in servo system. Servo motor can convert voltage signal to torque and speed, then to drive the control object. The control speed and position accuracy is very high. In auto control system, servo motor can response rapidly as executing component, convert the receiving electrical signal to angular displacement or angular velocity output of motor axis. The main feature is, when signal voltage is zero and no self-rotation, rotation speed will descend at even speed along with the torque increasing. Servo motor has 2 types, DC servo motor and AC servo motor.

Servo driver is a kind of controller used to control the servo motor, which belongs to the servo system. When some problems accur as follow of a servo drive, how we should test and repair? Here are 6 tips  to maintain a servo drive.

Stepper motor is an open loop control element that transforms the electrical pulse signal into angular displacement or linear displacement. When a pulse signal is added to the motor, and the motor turns a step angle. The existence of this linear relationship, and stepper motor with only periodic error and no accumulated error, makes it widely used in various fields. This article describes the application of stepper motor in electronic clocks, industrial robot and packaging machine.

Stepper motors is used in open-loop control, thus it is simple, low cost and can be widely used. However, the open-loop control of the stepper motor cannot avoid the inherent disadvantages of the stepper motor itself, that is, resonance, oscillation, step loss and difficult to achieve high speed. Correspondingly, the closed-loop control of stepper motor can make up these shortcomings, and have the advantages of open-loop drive and brushless DC servo motor.

Sometimes one has to (still) use a dedicated net just for servos but that is old. Different fieldbuses and/or servo drive interfaces may support a partial frame; for example, one may only be able to set a control word which might be position or torque command while some may support a full parameter frame or command set which exposes a plethora of servo parameters and variations between the two extremes. Speed is also a consideration i.e. may only be fast enough to do motion control or fast enough to close a servo torque loops and/or fast enough to incorporate feedback devices e.g. force or range sensors (without wiring directly to the servo drive).

Stepper motors are now widely used in the industrial areas, but from time to time some problems with stepper motors occurs as follows. Aimed to these problems, there are some troubleshooting for your reference.

1. How to control the direction of stepper motor?
2. When stepper motor generates vibration and noise, how to do it?
3. Why the stepper motor doesn’t rotate or move back and forth after it is powered?
4. Why the torque of stepper motor is decreasing with the rise in rotational velocity?
5. Why stepper motor can run normally at low velocity, but can’t start at certain higher velocity with some noise of whistler?
6. How to prevent the power interference of stepper motor?

Stepper motor is an open-loop control motor which transforms electric pulse signal into angular displacement or linear displacement.  However, there are some errors occuring between the actual angle stepper motor rotates and the theoretical step distance. There are some certain errors from one step to any other step, but the step number of each cycle of the stepper motor is the same. In the case of no step loss, the step error is not accumulated for a long time.
How to prevent step loss with stepper motor as the above mentioned? First of all, we need to know why stepper motor losses step?

1. The rotor acceleration is slower than the rotating magnetic field of the stepper motor.
2. The average speed of the rotor is higher than the average rotating speed of the stator magnetic field.
3. The load inertia of stepper motor is large.
4. The stepper motor produces the resonance.

The servo drive is a kind of controller to control the servo system. Its function is similar to the frequency effect on ordinary AC motor, which belongs to a part of the servo system and is mainly applied in high-accuracy positioning system. Generally, the servo motor is controlled by three ways, location, speed and torque, so as to realize high precision positioning of transmission system.

Stepper motor is an actuator transforming electric pulse into angular displacement. Popularly, when receiving a pulse signal, the stepper motor will rotate a fixed angle (namely"stepping angle") according to the direction set for the stepper motor. The angular displacement volume can be controlled by controlling the pulse number to achieve the purpose of positioning accurately. In the meantime, the rotational velocity and acceleration of motor can be controlled by controlling the pulse frequency to achieve the purpose of speed control.

Laser marking machine can provide the most professional solutions in the laser marking area of the whole automotive industry, from the car body, car frame, hub and tire, various hardware components, central control of the seat, steering wheel and instrument panel, glass, interior decoration, lighting, the assorted oils for cars, ornaments and so on.

It depends on specific application situation, and to put it in a simple way: Nature of load (for example, vertical load or horizontal load), requirements of torque, inertia, speed, accuracy and acceleration and deceleration, requirements of upper control (such as requirements of port interface and communication), whether major controlling mode is position, torque or speed mode, whether power supply is direct or alternating current power supply, or battery powered, and voltage scope. Based on this, we can determine models of motor and supporting drives or controllers.