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The impedance of N-wire is at the milliohm level, and its unbalanced voltage of load neutral point is the voltage drop of N-wire current on N-wire impedance with small value. Even if the three-phase load is seriously unbalanced, it is enough to clamp the neutral point potential of load on the neutral point potential of power supply. While the ground resistance is at the ohm level, which is several hundred times larger than the N-wire impedance, so it is impossible to clamp the neutral point potential of load on the neutral point potential of power supply.

With the rapid development of industrial automation, the variable frequency drive, used for frequency conversion debugging, is thereof widely used. As an important role of frequency conversion speed regulation and energy saving, VFD is mainly used to control the AC motor's power control equipment by changing the frequency of the motor's working power supply. It's not only advantageous for improving the enterprise's process and production level, but also plays an important role in energy saving. But how should we choose an appropriate VFD?

The ATO 1000-50000mm draw-wire displacement sensor has a small mounting size, compact structure and high precision. Its measuring range can be 1000mm/2500mm/5000mm or even 50000mm. This draw-wire displacement sensor is particularly suitable for linear rolling guide system, hydraulic cylinder system, testing machine, telescopic system (forklift, press, lifter, pipe bender, bending machine, etc), crane or cable winch, reservoir dam protection system, gate opening control system, pressure machine, hydraulic universal experimental machinery, warehouse location position, length and displacement measurement and position control of various industrial instruments.

Pancake load cell is also known as low profile load cell, because it has a low profile design and it looks like a pancake. On the other hand, pancake load cell can bear both tension and compression force. So it is also a tension and compression load cell that is widely used for platform scale, truck scale, rail weighbridge and tension tester.

Traditional phase conversion system adopts rotary transformation technology, which has 50 years of history and simple product structure in early times. It consists of a transformer, three-phase motor, capacitor and relay control circuit. As long as the 220V power is connected, the auxiliary motor starts, the starting capacitor is disconnected and the motor is turned into a generator, thus producing missing phase. A fairly rough three-phase electric lead can be produced to provide power supply for other electrical equipment. Such a traditional conversion system doesn't have the adaptive control function, so there are many defects in its application. When the load varies widely, the three-phase output voltage will be unbalanced. At free load or light load conditions, the output voltage will rise to more than 25% of the rated output voltage; When the load is too large, it will also greatly reduce the output voltage, making it difficult for the device to start or stop running. However, the single phase to 3 phase power converter of ATO uses many important new technologies, the newly invented built-in micro-control computer control program makes our products to have a qualitative leap in conversion efficiency and performance.

The oscilloscope probe is mainly used to guide the measured voltage signal from the measuring point into the oscilloscope for measurement. Probe is crucial to the accuracy and correctness of the measurement results, as it's the electronic component connecting the measured circuit and the input of the oscilloscope. The simplest probe is a wire that connects the measured circuit and the input of the oscilloscope, a complex probe consists of resistor-capacitor unit and active devices. A simple probe has no shielding measures, so it's susceptible to external electromagnetic interference. Meanwhile, larger equivalent capacitance in it would increase the load on the measured circuit, thus leading to distortion of the measured signal.

A pH electrode is a part of the pH meter contacting with measured substance. It's used to measure the electrode potential. Generally, there are two methods to measure the pH value of the aqueous solutions, namely Colorimetry (pH test paper and cuvette) and potentiometric method. The latter is the only way to realize continuous on-line measurement and process monitoring. Moreover, it can obtain accurate and repeatable pH value. The electrode used in the potentiometric method is called as primary battery, which is a system used to converse the chemical reaction energy into electrical energy, voltage of the primary battery is called for electrodynamic force (EMF).

What is the principle of the chemical element analysis instrument?
Chemical analysis instrument is mainly used for in-site measurement of elements in metal materials in the military industry, aerospace, iron and steel, petrochemical, power, pharmaceutical and other fields, it's an indispensable tool for rapid identification of materials in the industrial and military manufacturing fields accompanying the rise of the world economy.
Principle of chemical element analysis instrument.

A pH meter is an digital instrument used to test and monitor the pH value of a solution. It works by the principle of primary battery, of which the electromotive force between two electrodes is based on the Nernst Law. Electromotive force of primary battery is affected by both property of electrodes and hydrogen ion concentration in the solution. There is a correspondence relationship between the electromotive force and hydrogen ion concentration of the primary battery, namely negative logarithm of the hydrogen ion concentration is equal to the pH value.

As a common electrical actuator, stepper motor is widely applied in automatic control field. Stepper motor needs to be equipped with a special drive power the output of which is controlled by external pulse signal and direction signal. Each pulse signal can make stepper motor rotate a fixed angle, which is called step angle. Total angle and speed of rotation respectively depend on the number and frequency of pulse. The direction of rotation depends on direction signal. For a equipment with a known transmission ratio, the movement distance and speed of its parts can be controlled by controlling the number and frequency of pulse without the requirements for the feedback of distance and speed signals; and direction signal can control moving direction. Therefore, open loop control is a simple and economic electronic control technical scheme.

Power supply is an important part of the circuit design, and the stability of the power supply determines the stability of the circuit to a large extent. Linear power supply and switching power supply are two common power supplies, and they have a great difference in the principles which determine the difference between the two applications.

Self-healing type low voltage shunt capacitor is suitable for the AC power system with working frequency 50Hz or 60Hz, rated voltage 1000V and below and is connected in parallel with load, in order to improve the power factor of system and reduce line loss, improving the voltage quality. It is widely used to improve the efficiency of power supply equipment, local compensation of the inductive equipment such as motor and transformer and electric furnace, electric traction engine, UPS systems and power system harmonic filtration and other aspects.

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.

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.

The opening area needs to be set when constantly sending in and out parts on a dangerous high-speed operation machine. If a protective door is set here, it will seriously affect the production and certainly not be able to take both production and safety into account. Safety light curtain is a safety device set in these openings, and it realizes safety protection through the light beams. It is a type of sensor that install through beam photoelectric sensors in rows from top to bottom. It monitors a certain range of amplitude, when the machine is running, it intercepts the light when a human body intrudes, and stops the machine to achieve the purpose of protecting personal safety. However, when processed parts are fed in and out through the light curtain, they do not cause the machine to stop working. In this way, the operators are effectively protected from harm without affecting the production at the same time.

How does an electromagnetic relay work? Electromagnetic relay uses electromagnet to control “on” or “off” status of the operating circuit. Electromagnetic relay consists of electromagnet, armature, spring, movable contact and stationary contact. When placing voltage to both ends of a coil, the coil will be flowed with current and generate electromagnetic effect.

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.

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.

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...