The so-called intermediate relay is used in relay protection and automatic control system to increase the number and capacity of contacts.

它用于在控制电路中传递中间信号。

It is used to transmit intermediate signals in the control circuit.

中间继电器的结构和原理与交流接触器基本相同，与接触器的主要区别在于：接触器的主触头可以通过大电流，而中间继电器的触头只能通过小电流。

The structure and principle of the intermediate relay are basically the same as that of the AC contactor. The main difference from the contactor is that the main contact of the contactor can pass through large current, while the contact of the intermediate relay can only pass through small current.

因此，它只能用于控制电路中。

Therefore, it can only be used in the control circuit.

它一般是没有主触点的，因为过载能力比较小。

It generally has no main contact, because the overload capacity is relatively small.

因此，它用的全部都是辅助触头，数量比较多。新国标对中间继电器的定义是K，老国标是KA。一般是直流电源供

Therefore, all auxiliary contacts are used, and the number is relatively large. The definition of intermediate relay in the new national standard is k, and the old national standard is Ka. Usually DC power supply

中间继电器作用是用来传递信号或同时控制多个电路，也可直接用它来控制小容量电动机或其他电气执行元件，它的结构和交流接触器基本相同，只是电磁系统小些，触点多些。

The function of intermediate relay is to transmit signals or control multiple circuits at the same time. It can also be directly used to control small capacity motors or other electrical actuators. Its structure is basically the same as that of AC contactors, except that the electromagnetic system is smaller and there are more contacts.

继电器的工作原理是当某一输入量(如电压、电流、温度、速度、压力等)达到预定数值时，使它动作，以改变控制电路的工作状态，从而实现既定的控制或保护的目的。在此过程中，继电器主要起了传递信号的作用。

The working principle of the relay is to make it act when an input (such as voltage, current, temperature, speed, pressure, etc.) reaches a predetermined value, so as to change the working state of the control circuit, so as to achieve the established purpose of control or protection. In this process, the relay mainly plays the role of transmitting signals.

常用的中间继电器主要有JZ7系列和JZ8系列两种，后者是交直流两用的。在选用中间继电器时，主要是考虑电压等级以及常开和常闭触点的数量。

There are two kinds of commonly used intermediate relays: JZ7 series and jz8 series, which are AC and DC dual-purpose. When selecting the intermediate relay, the voltage level and the number of normally open and normally closed contacts are mainly considered.