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It is found that the speed of air compressor motor is proportional to the actual consumed power of the air compressor. Therefore, it is necessary to reduce the motor speed in order to reduce the actual consumption of the air compressor. The use of VFD in air compressor system can realize the real time control of motor speed (output power) without changing the air compressor motor torque through the accurate coordination of electrical control and frequency control in the air compressor system. To change the compressor speed to respond to the system pressure changes and to maintain stable system pressure can realize the output of high quality air pressure according to demand.

When a current spike or voltage surge suddenly occurs in an electrical circuit or a communication line due to external interference like lightning, surge protection device (SPD) can conduct the shunt in a very short time, thereby avoiding the damage of the surge to other equipment in the circuit. It is an indispensable device for lightning protection in the electronic equipment. But some people are still wondering why we need it, or whether need it when we have other lightning protection device? The following FAQ will give your answer for "Why you need a surge protection device".

In the actual use of some low pressure and medium pressure piston type portable air compressor, the two stage compression is often used. The intermediate cooler is set. After the cooling of high temperature air discharged from single stage compression, it is then inhaled into two stage cylinder for two stage compression so as to reach the required pressure. Adopt two stage compression, because if use single stage compression to obtain higher air pressure, the pressure ratio (the ratio of the exhaust pressure and suction pressure) is too large, so that the compression process.

In practical application, after human body intrudes into the range of safety light curtain, besides that safety light curtain needs certain response time, the machine also needs certain braking time. Therefore, to guarantee personal safety of operators, installation position of safety light curtain must meet requirements of safety distance. Otherwise, there is still the possibility of an accident.

Generally speaking, one of the commonly used methods to achieve precise linear positioning is to make a set of linear positioning system by pairing the motor with the sliding bar. Here we will discuss several different ways to create a linear actuator by using the sliding bar and stepper motor. The stepper motor is the most commonly used selection in the application of motor control because if the operation is correct, it is an economic solution that can achieve accurate positioning without the need of position feedback.
Stepper linear actuator can be divided into three types, external shaft type, non-captive shaft type and captive type.

All electrical equipments have their rated power. It is called overload when they surpass the rated power, and protection to the status is called overload protection. Protection to prevent internal short circuit of electrical equipment is called short circuit protection and zero-pressure is also called no-voltage protection. When there is power failure, circuit with the functions mentioned above will stop automatically and electric equipment will not start automatically when power is supplied next time. the purpose of the function is to prevent operating personnel forget cut off power source when there is power failure and electric equipment operate automatically next time when there is power and thus cause accidents. General contractor-controlled circuit has this function.

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.