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Lin Hao Electric takes you step by step to understand the application of time relay in industrial control

Take you step by step to understand the application of time relay in industrial control

The time relay belongs to the category of low-voltage electrical appliances. If classified according to the classification, it should be classified as the electromechanical control electrical appliances of low-voltage electrical appliances. It is a kind of machine tool electrical appliances commonly used in automatic control systems. The history of its development can be traced back to the 1970s. The delay-triggering time control circuit completed by the traditional electric time relay or RC charging circuit and single junction transistor has been widely used in general CMOS integrated circuits. Multi-delay function (power-on delay, on-delay, power-off delay, off-delay, reciprocating delay, interval timing, etc.), multi-setting method (potentiometer setting, Digital dial switch, button, etc.), multiple time base selection (0.01s, 1s, 1m, 1h, etc.), multiple working modes, LED relay time display. Because it has many advantages such as high delay accuracy, wide delay range, and intuitive delay display during the delay process, which are incomparable with traditional time relays, it has basically replaced the traditional time relay in the field of automatic control today.

Lin Hao Electric takes you step by step to understand the application of time relay in industrial control

Although the time controller started late in China, it has also made considerable progress in the field of time relays. In recent years, with the continuous development of China's electronic technology and the large number of domestic time relay chip development and application, it has largely made domestic The time relay has made great progress in both appearance and product performance. Especially on the basis of the special chip, the chip mask technology is adopted, and the core part of the relay is masked on the printed circuit board, so that the time relay is changed from LED digital display to LCD liquid crystal display, plus SMD patch is commonly used. Electronic components make the appearance of the product more compact, and the product performance is more stable. Users can use the dial or function buttons on the panel peripherals to preset the time or control mode. Some products are basically used in specific applications. Equivalent to foreign products.

In summary, the time relay is a controller whose delay function is realized by electronic circuits. It can be widely used for time control and indication in automatic control circuits.

The time relay is widely used as an automatic control device, especially when it is used in an environment where there are many electrical equipments in a low-voltage electrical control network, and the electromagnetic interference problem becomes more serious. The damage of the internal components that make up the time relay is not the main cause of the time relay failure (failure) at this time, but the various interferences in the application place directly enter the time relay through electromagnetic coupling and capacitive coupling, and interfere with its normal delay control. Whether the time relay can work normally in this interference environment often affects the normal logic function of the entire automatic control system, and may even cause large quality accidents and economic losses. Therefore, the time relay should have high reliability and anti-interference ability in various harsh environments. That is to say, the time relay must have good electromagnetic compatibility performance. Only in this way can its product quality be improved and its own market competitiveness.

The development of time relays has been completed by early separation devices. Now there are dedicated CMOS time relay chips to replace them. Regardless of time accuracy, the delay method has been greatly developed, especially in recent years. Controllers (PLCs) are widely used in the field of automatic time control because of their versatility, good flexibility, complete hardware, complete programming methods, easy learning and high reliability, and the use of this PLC has occupied the existing time relay market The corresponding market share, and this trend is gradually expanding, it is likely that in the near future, PLC will play a more important role in the field of automatic control.

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