Intermediate relay is used in relay protection and automatic control system to increase the number and capacity of contacts. It is also used to transmit intermediate signal in control circuit. There are two main delay modes of intermediate relay, which are power on delay and power-off delay. The installation modes are mainly divided into fixed, protruding, embedded and rail type. It generally has no main contact, because the overload capacity is relatively small. So it uses all auxiliary contacts, the number is more.

ABB中間繼電器就是個繼電器，都是由固定鐵芯、動鐵芯、彈簧、動觸點、靜觸點、線圈、接線端子和外殼組成。線圈通電，動鐵芯在電磁力作用下動作吸合，帶動動觸點動作，使常閉觸點分開，常開觸點閉合;線圈斷電，動鐵芯在彈簧的作用下帶動動觸點復位。

ABB intermediate relay is a relay, which is composed of fixed iron core, moving iron core, spring, moving contact, static contact, coil, terminal and shell. When the coil is electrified, the moving iron core acts to pull in under the action of electromagnetic force, and the moving contact acts to separate the normally closed contact and close the normally open contact; When the coil is powered off, the moving iron core drives the moving contact to reset under the action of the spring.

工業控制線路和現在的家用電器控制線路中，常常會有中間繼電器存在，對于不同的控制線路，中間繼電器的作用有所不同，其在線路中的作用常見的有以下幾種。

Industrial control circuit and the current home appliances control circuit, there are often intermediate relays, for different control circuits, the role of intermediate relays are different, the common role in the circuit are the following.

1、作用之一--代替小型接觸器

1. One of the functions -- to replace the small contactor

中間繼電器的觸點具有一定的帶負荷能力，當負載容量比較小時，可以用來替代小型接觸器使用，比如電動卷閘門和一些小家電的控制。這樣不僅可以起到控制的目的，而且可以節省空間，使電器的控制部分做得比較精致。

The contact of the intermediate relay has a certain load capacity. When the load capacity is relatively small, it can be used to replace small contactors, such as the control of electric rolling gate and some small household appliances. This not only can play the purpose of control, but also can save space, so that the control part of electrical appliances do more delicate.

2、作用之二--增加接點數量

2. The second function is to increase the number of contacts

在電路控制系統中，線路中增加一個中間繼電器，不僅不會改變控制形式、增加接點數量，而且便于維修。

In the circuit control system, adding an intermediate relay in the circuit not only does not change the control form and increase the number of contacts, but also is convenient for maintenance.

3、作用之三--增加接點容量

3. The third function is to increase the contact capacity

中間繼電器的接點容量雖然不是很大，但也具有一定的帶負載能力，同時其驅動所需要的電流又很小，因此可以用中間繼電器來擴大接點容量。而在控制線路中使用中間繼電器，通過中間繼電器來控制其他負載，達到擴大控制容量的目的。

Although the contact capacity of the intermediate relay is not very large, it also has a certain load capacity. At the same time, the current required for its drive is very small, so the intermediate relay can be used to expand the contact capacity. The intermediate relay is used in the control circuit to control other loads, so as to expand the control capacity.

4、作用之四--轉換接點類型

4. Function 4 -- type of transfer contact

在工業控制線路中，可以將一個中間繼電器與原來的接觸器線圈并聯，用中間繼電器的常閉接點去控制相應的元件，轉換一下接點類型，可以實現需要使用接觸器的常閉接點才能達到控制目的。

In the industrial control circuit, an intermediate relay can be paralleled with the original contactor coil, and the normally closed contact of the intermediate relay can be used to control the corresponding components, and the contact type can be changed, so that the normally closed contact of the contactor can be used to achieve the control purpose.

5、作用之五--用作開關

5. Function 5: used as a switch

在一些控制線路中，一些電器元件的通斷常常使用中間繼電器，用其接點的開閉來控制。如彩電或顯示器中常見的自動消磁電路，三極管控制中間繼電器的通斷，從而達到控制消磁線圈通斷的作用。

In some control circuits, the on-off of some electrical components often uses the intermediate relay, which is controlled by the opening and closing of its contact. For example, in the common automatic degaussing circuit of color TV or display, the triode controls the on-off of intermediate relay, so as to control the on-off of degaussing coil.

6、作用之六--轉換電壓

6. Function 6 -- switching voltage

在工業控制線路控制線路中電壓是DC24V，而電磁閥的線圈電壓是AC220V，安裝一個中間繼電器，可以將直流與交流、高壓與低壓分開，便于以后的維修并有利于安 全使用。

In the industrial control circuit, the voltage of the control circuit is DC24 V, while the coil voltage of the solenoid valve is AC220 v. installing an intermediate relay can separate DC from AC, high voltage from low voltage, which is convenient for future maintenance and safe use.

7、作用之七--消 除電路中的干擾

7. The seventh function is to eliminate the interference in the circuit

在工業控制或計算機控制線路中，雖然有各種各樣的干擾抑 制措施，但干擾現象還是或多或少地存在著，在內部加入一個中間繼電器，可以達到了消 除干擾的目的.

In the industrial control or computer control circuit, although there are various interference suppression measures, the interference phenomenon still exists more or less. Adding an intermediate relay inside can achieve the purpose of eliminating interference