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As equipment to disconnect load power, selection of contactor should meet requirements of controlled equipment. Except that the rated operational voltage is the same with the rated operational voltage of controlled equipment, load power, usage category, control mode, operation frequency, working life, installation method, installation dimension and economy of controlled equipment are the basis of selection. How to choose a right contactor? The principles are as follows:

Stator of linear motor has a relatively strong magnetism, thus there will be some specific problems during application. Therefore, proper solutions to the problems are the key to success application, and the following aspects should be concerned in specific application:
Guarantee mounting dimension between active cell and stator
The gap between active cell and stator of linear motor is one important parameter, and any small changes can cause great changes of property of motor. Over big gap can directly affect output of linear motor; while over small gap can possibly cause damages to motor since it absorbs other things. Therefore, in installation, it must strictly control to guarantee normal operation of motor.

Solenoid valve is one of the most commonly used valves in automatic control system. It is favored by users because it is cheap, simple to operate, convenient and reliable, which can directly receive switch signals of PLC or DCS. Of course, only when it is used properly can the solenoid valve play its full role. Here are some tips in the installation and maintenance of solenoid valves for your reference.
Installation

• First check whether the solenoid valve is consistent with the selection parameters, such as power supply voltage, medium pressure, pressure differential etc. If the voltage of power supply is chosen wrongly, it will burn the coil. Generally, the power supply voltage should meet the fluctuation range of rated voltage: AC +10%~-15%, or DC +10%~-10%. Besides, the coil components should not be disassembled normally.
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Three-phase imbalance means that inconsistent amplitude of three-phase current (or voltage) in electrical power system and that amplitude difference surpasses the specified range.
Unbalanced current of transformer refers to current difference of three-phase transformer windings. The current difference is mainly caused by different three-phase load. Asymmetry of load gives rise to asymmetry of three-phase current which flow through transformer. And current asymmetry causes asymmetry of three-phase impedance drop of transformer, thus three-phase voltage of secondary side is asymmetric, which will do harm to transformer and electric equipment.

Solenoid valve is a basic component of automation to control the fluid, which widely applied both in the industry and in our daily life. Now and then, this small valve encounters some problems, which further affects the normal operation of the whole equipment. So, it would be better to learn some common problems of solenoid valve and know how to trouble shoot them. Here are some common problems occurring with solenoid valves for your reference.

• Solenoid valve doesn’t work after energized.
• The valve cannot be closed.
• There is a leakage inside or outside the solenoid valve.
• There is a noise after the valve power on.

DC contactor is mainly used to control the DC circuit, it has no impact on the starting current, and will not produce iron core impact, so the service life is long, suitable for frequent start and stop occasions. ATO provides a wide range of DC contactors including universal DC contactors, high voltage DC contactors and DC reversing contactors. Rating current of them from 30 amps to 600 amps, available with 12V, 24V, 48V DC coil. Look at the price of ATO DC concactors listed in the table below, it's cheaper for you to get one from us.

The solenoid valve is one of the products for fluid control automation. According to the start-up working model of the solenoid valve, it can be divided into the most frequently-used two categories: pilot-operated solenoid valve and direct acting solenoid valve. However, if not choose the right one, it easily causes the solenoid valve does not work. Meanwhile, it will somewhat affect the safety of the application. Then, how to distinguish the difference between pilot-operated and direct acting solenoid valve? How to choose the right one for the better application? The following will give you some enlightenment.

Stepper motor is to receive the pulse current to achieve speed, position and direction of control. The number of pulses determines the position of the stepper motor, the pulse rate determines the motor speed and pulse direction determines the steering of motor. The control mode of most stepper motor is using PLC to send pulses to the driver and then drive motor to operate. Pulse mode has been around for several decades, and for some applications requiring high frequency, the pulse type can no longer meet the requirements, and it needs to be controlled by the bus type.

The solenoid valve is industrial equipment controlled by electromagnetism. It is an automatic basic element to control the fluid. It belongs to the actuator, but not limits to the hydraulic pressure and pneumatic control. In the industrial control system, the solenoid valve is used to regulate the direction, flow rate, speed and other parameters of the medium. The solenoid valve can coordinate with different circuits to realize the anticipated control, with both control precision and flexibility being guaranteed.

A servo motor is an actuator that allows for precise control of angular position in automatic control system. It also requires a servo drive to complete the system. The drive uses the feedback sensor to precisely control the rotary position of the motor. Compared with other motors, such as stepper motors and AC induction motors, what are the advantages of servo motors?

• The servo motor realizes the closed loop control of position, speed and torque, and overcomes the problem of stepper motor losing step.
• The servo motor has high speed performance, and the normal rated speed can reach 2000 ~ 3000 rpm.
• The servo motor has strong resistance to overload, and can withstand three times the load of rated torque. It is especially suitable for the occasion of instantaneous load fluctuation and fast starting.
• The servo motor runs smoothly at low speed, and it does not produce the step running phenomenon similar to stepper motor. It is suitable for situations with high speed response requirements.
• The dynamic time of motor acceleration and deceleration is short, usually within tens of milliseconds.
• The heat and noise of the motor are obviously reduced.

Troubles with the induction motors are generally divided into two categories. One is the electrical faults, such as the various faults of switches, buttons, fuses, electric brushes, stator winding, rotor, starting equipment and so on. The other is the mechanical problems, such as the problems of the bearing, fan blade, motor frame, coupling, end bell, bearing cover, spindle and so on.
Once the induction motor has any problem, there might be some abnormal phenomena, for instance, the rising temperature, over current, vibration and abnormal noise and so on. Therefore, learn about these phenomena, find out the cause, and then troubleshoot it. The following is some common faults and troubleshooting method of three-phase induction motors for your reference.

Switching power supply (SMPS) is widely used due to its compact size, light weight and high efficiency. But it has its own disadvantage of producing noises, which not only affect the normal operation of the circuit, but also interfere with the neighboring electronic equipment. So how to reduce the noise of SMPS? First of all, we need know where the noise comes from, and then we can eliminate it accordingly.
The noise of switching power supply can be divided into two major categories: one is the interference formed by the internal components of SMPS, and the other is the interference caused by the external factors. There are many sources of noise, such as external interference like lightning, mechanical vibration, poor contact and so on. Besides, improper design of circuit, improper parameter selection of components, unreasonable layout and wiring will also increase the power supply noise.

How to control the speed of three phase induction motor? The speed control method includes: changing the number of poles, stator voltage control, stator frequency conversion, cascade speed control, double-feed speed regulation, hydraulic coupler, electromagnetic slip clutch, etc.
The actual speed of three phase asynchronous motor is given by n=n_s (1 - s) =120f /p (1-s). It can be seen from the formula that the speed of 3 phase induction motor can be changed by the means of changing the number of induction motor’s poles "p", the slip "s" and the frequency of power supply"f".

Circuit breakers and fuses can protect the electric equipment and lines from short circuit. Actually, both have their own characteristics. Circuit breakers are used to switch on and off the load circuit as well as cut off the fault circuit, so as to ensure the safety. The fuse is used as a protector by melting itself when the current is too high or exceeds the load current. It is completely different from the circuit breaker on the breaking current. Its function can be easily understood by the commonly used fuse in our home.

A brushless DC (BLDC) motor is highly reliable since it does not have any brushes to wear out and replace, brushless design for high speeds, long life and high power density. ATO has a wide selection of high quality and good performance brushless DC motors to meet your specific needs. They come in different size to provide you the right torque for your application. The price of our brushless DC motors listed in the form are reasonable and for reference only. If you want more information, please go to ATO brushless DC motors products page.

Stepper motor is an actuator that transforms the digital pulse signal into angular displacement. Namely, when stepper drive receives a pulse signal, it drives the stepper motor to rotate at a fixed angle (i.e. step angle) in the set direction. Stepper motor is a main executive component in the modern digital control system, and has a very wide range of applications because of the following advantages:

• Precise position control, as confirm the shaft rotation angle in accordance with the number of input pulses.
• Wide speed range, because the speed is proportional to the pulse frequency.
• Excellent starting and stopping as well as reverse response.
• Able to synchronously rotate at an extremely low speed just directly connecting the load to the motor shaft.
• Long service life. Unlike DC motors, stepper motors don’t need to adjust phase position by the brush and commutator, thus reducing the friction and increasing the service life.

A power line filter, also called EMI power line filter, is a filter circuit composed of capacitors, inductors and resistors. It is a passive bi-directional network, one end of which is connected with the power supply and the other end is the load. The power line filter works based on the principle of impedance matching network: the bigger the impedance matching between the input and output of power line filter and the load is, the more effective the attenuation of electromagnetic interference is.
ATO power line filters are characterized with excellent differential mode and common mode attenuation performance to suppress EMI or RFI, which provide an electromagnetic shielding for your equipment or device.

How does an 3-phase induction motor work? In short, it works based on the principle of electromagnetic induction. When the stator windings are supplied with three-phase alternating current, a rotating magnetic field is generated between the stator and the rotor. The rotating magnetic field cuts the rotor windings to generate induced electromotive force and current in the rotor circuit. The current in the rotor conductor forces the rotor to rotate under the effect of the rotating magnetic field. Below, let’s specifically analyze the generation of rotating magnetic field, its direction and speed as well as slip.

The starting methods of three phase induction motor generally are direct-on-line starting, reduced-voltage starting and soft starter.
Direct-on-line starting is the most basic and simplest in the motor starting. The method is characterized by less investment, simple equipment and small quantity. Although the starting time is short, the torque is smaller at starting and the current is large, which is suitable for starting small capacity motors.

Induction motor, also known as asynchronous motor, is a kind of AC electric motor. According to the different power phase, it can be divided into single-phase and three-phase. The main construction of induction motor is composed of two parts - stator and rotor. In addition, there are end bells, bearings, motor frame and other components. The following will give more details about the structure of three-phase induction motor or asynchronous motor.