Tag: difference between

The instrument transformers like current transformer and potential transformer (also called voltage transformer) are both used for measuring devices, which have a similar working principle to transformers. The current transformer can reduce the high current to low current, while the potential transformer steps down the high voltage to low voltage for measuring the circuit or in the power distribution. They both separate the measurement circuit from the high-voltage grid to protect safety of the personnel.

Relays and transistors have a similar basic function, that is, both play roles of electronic switches. However, relays and transistors are very different from each other. Now let’s take a quick peek at the differences between relays and transistors.

What is the frequency converter? Frequency converter outputs the AC power to pure sine wave after the transformation of AC→DC→AC, the output frequency and voltage can be adjusted within a certain range. It is different from the variable frequency drive (VFD) used for motor speed regulation, and also different from the common AC regulated power supply. An ideal AC power supply is characterized by stable frequency, stable voltage, zero internal resistance and pure sinusoidal voltage waveform (without distortion). Frequency converter is quite close to the ideal AC power supply, so more and more countries use it as standard power supply to provide the best power supply environment for electrical appliances, so as to assess the technical performance of electrical appliances.

Image sensor is an important part of the industrial camera. According to difference of the original, it can be divided into CCD and CMOS sensors. In the last 25 years of the last century, CCD technology has been leading the trend of the imaging sensor. It is a high-resolution and high-quality image sensor which can be integrated on a very small chip. However, in recent years, with the rapid development of the semiconductor manufacturing technology, the size of the integrated transistor is becoming smaller and smaller, and the performance is much better. CMOS image sensor obtains rapid development in the recent years, and it seems CMOS image sensor has overtaken CCD image sensor. CMOS provides the performance on a par with CCD in the mid-end and low-end applications, and has a significant advantage in price. With the development of technology, CMOS will also occupy a space in the high-end application field. This paper makes a detailed explanation to the difference between CCD and CMOS image sensors in the industrial camera.

Have you ever though why your motor has a shorter service life than that of others? Let us tell you, your motor may need a soft starter. Generally, the motor shall adopt a soft starter as soon as its power exceeds 20hp (15kW), otherwise it will affect the use and operation of other equipment in power grid and damage the motor. Why should the soft start controller be used? What are the benefits of using motor soft starter?

As the common part of the electrical device, both the surge protection device and lightning arrester have the function of preventing from over-voltage, especially preventing from the lightning over-voltage. However, the two have great differences.

• Different voltage level from the perspective of application field
• Different protecting objects
• Different insulation level or withstand voltage level
• Different installation position

Current transformer is mainly used to measure the current of busbar and primary side with iron core coils in AC occasion. It can detect the DC current, can be single core or dual cores, generally, it's equipped with auxiliary DC winding. Such a structure is simple, reliable and slow. Technology and design of the current transformer are complex, its common precision is 5%, it's difficult to reach 0.5% because phase position and compensation are difficult. A current transformer is an electrical component that turns large current into small current, it doesn't change the current frequency but only the size. Its secondary side current is 5A, that means the output rated current is 5A. It's mainly used for electrical control, measurement, protection and signal.

The gas solenoid valve is used for various ambient temperature, high temperature, negative pressure, low pressure and high pressure applications. The applicable fluid is air, nitrogen, oxygen, hydrogen, helium, carbon dioxide gas, argon gas, methane and other gas pipelines. Generally, solenoid valve for gas is mainly used in wide applications such as medical apparatus and instruments, rubber plastic machinery, clothing equipment, drying equipment and pharmacy industry, cooling industry, HVAC industry, electroplating coating industry, food and beverage industry and vacuum equipment industry.

As everyone knows, direct starting of water pump would cause the water hammer effect. Namely when the water pump starts and stops, water impacts the pipe and cause a serious water hammer. When the power is off suddenly or the valve turns off quickly, a water impact wave generates due to inertia of pressure flow, which is like the knock of a hammer, so it’s called water hammer. Sometimes the force generated from water impact wave may be great and damage valve or pump, therefore, to avoid the negative effect of water hammer effect, the pump’s rotation speed should increase to the rated speed slowly when it’s started. Two methods are applicable, one is the variable frequency starting, another is the soft starting.

Safety relay has special color, generally yellow. Current safety relay acts reliably and flexibly, it's mainly used to control the power supply circuit. When an emergency occurs, the circuit controlled by the safety relay is disconnected by pressing the emergency stop switch, thus ensuring safety.

Infrared temperature measurement technology plays an important role in production, product quality control and monitoring, on-line fault diagnosis and safety protection, as well as energy saving. Compared with the contact-type temperature measurement method, infrared temperature measurement has the advantages of fast response time, non-contact, safe use and long service life. Non-contact infrared thermometer involves three major series of portable, on-line and scanning thermometer, with various accessories and computer software. Moreover, each series has different types and specifications. Among these thermometers with various specifications, it is very important for users to choose a correct type of infrared thermometer.

Iron core of the AC contactor is usually laminated by silicon steel sheet, so as to reduce the eddy current and hysteresis loss generated by alternating magnetic field in iron core, avoid the iron core overheating. However, iron core in the DC contactor's coil would not generate eddy current and there is no heating problem in DC core, so the iron core can be made of a complete cast steel or cast iron. Coil of DC circuit has no inductance, so the coil has more turns, thus leading to large resistance and copper loss. In order to keep a good heat dissipation for the coil, the coil is generally made into a thin and cylindrical shape. Coil of AC contactor has less turns and small resistance, but the coil also gives heat, so the coil is generally made into a fat and short cylindrical shape. Meanwhile, a clearance is left to facilitate heat dissipation while avoiding the coils from being burned out. In order to eliminate vibration and noise generated by electromagnet, a short circuit ring is embedded on the surface of static iron core of the AC contactor, while the DC contactor doesn't need a short circuit ring.

Industrial thermocouple and RTD protective casing are almost the same. Some temperature measuring elements are small in size, such as the armored type, and they also have similar shape. So, how to identify whether it is RTD or thermocouple without nameplate or unknowing the type? The following methods are listed to figure out the RTD and thermocouple for your reference.

Industrial camera can be divided into interlaced scanning industrial cameras and progressive scanning industrial camera according to scanning mode.
Most displays and industrial cameras adopt the interlaced scanning, but it actually looks like a smooth image in human eyes. Industrial cameras usually get odd rows of images first, for CCIR standard, industrial cameras get the even rows after 1/50 seconds, but for EIA standard, the industrial cameras get the even rows after 1/60 seconds.

The common line reactors in electrical power system include series reactors and paralleling reactors. Series reactors are mainly used to limit short-circuit current or ultraharmonics in filter by connecting with capacitor in series or in parallel. The line reactors in power grid of 220kV, 110kV, 35kV and 10kV are used to absorb the idle work of charging capacity of cable line. Operating voltage can be adjusted by adjusting the number of line reactors in parallel. Ultra-high voltage paralleling reactor can improve the operation conditions relating to reactive power of electrical power system including:

The gas detector only provides qualitative analysis results and rough quantitative analysis data, the data shown by this instrument can't stand out and error analysis can not be carried out (because "error" is only applicable when the analysis data deviates from the true value slightly), therefore the data can't be used as an accurate analysis data to determine the improvement and adjustment measures of important process. However, the gas analyzer is a strict measuring instrument providing rather accurate data in quantitative analysis, and the data can used as the basis for improvement of gas production and safety production, to guide the production management, quality management and enterprise management. Moreover, such data can be used as an important basis for judicial investigation and can be used in litigation to determine the right or wrong boundaries.

Industrial Personal Computer is called industrial PC for short, it's mainly used in the industrial production; Normal computer is called PC for short and is mainly used in personnel or business. Because of the different applications, the technical requirements are different. Ordinary household or office computer is a civil class, while the industrial PC is a industrial level, which has special requirements in structure and other aspects.
On the appearance, the normal computers are open with many heat dissipation holes on the appearance, only a power fan is used to blow outwards to dissipate heat. However, the industrial PC case is completely closed and it's much heavier than the normal computer, meaning that its material is thicker and stronger. It not only has a fan inside, but also another fan to ensure the positive pressure in the case.

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.

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.