说到继电器，一定会有人把它和接触器关联起来，也许认为他们是一样的东西。事实上，它们的工作原理是一样的，但也存在着电气上的区别。简单地可用以下几点来区分：
When it comes to relays, someone will associate it with the contactor, and maybe think they're the same thing. In fact, they work in the same way, but there are electrical differences. It can be easily distinguished by the following points:
第一， 接触器用来接通或断开功率较大的负载，用在(功率)主电路中，主触头可能带有连锁接点以表示主触头的开闭状态。一般主电路通过的电流比控制电路大。容量大的接触器一般都带有灭弧罩。
First, the contactor is used to connect or disconnect the power load, which is used in the main circuit of the power, and the main contact may have a chain contact to indicate the opening and closing state of the main contact. The main circuit of the main circuit is larger than the current control circuit. Large capacity contactors usually have arc shields.
第二，继电器一般用在电器控制电路中，用来放大微型或小型继电器的触点容量，以驱动较大的负载。如可以用继电器的触点去接通或断开接触器的线圈。一般继电器都有较多的开闭触点，当然继电器通过适当的接法还可以实现某些特殊功能，如逻辑运算等。
Second, the relay is generally used in the electrical control circuit, used to enlarge the contact capacity of micro or small relays, to drive larger loads. If the contact of the relay can be used to connect or disconnect the coil of the contactor. General relays have more open and close contacts. Of course, relays can also perform some special functions, such as logical operations, through proper connection.
第三， 以上两者相同之处：都是通过控制线圈的有电或无电来驱动触头的开闭，以断开或接通电路。属于有接点电器。线圈的控制电路与触点所在的电气回路是电气隔离的。
Third, the above two are the same: they are controlled by the coil of electricity or no electricity to drive the opening and closing of contacts, to disconnect or switch on the circuit. Contact electrical appliance. The control circuit of the coil is electrically isolated from the electrical circuit where the contact is located.
第四， 触发器一般是指数字逻辑器件(如集成芯片)，通过外部触发条件实现一定的逻辑功能。如d触发器、t触发器、j-k触发器、r-s触发器等。简单的触发器也可以用分离电子器件来实现。触发方式有多种，如：上升沿、下降沿、高电平、低电平。
Fourth, flip flops generally refer to digital logic devices (such as integrated chips), through the external trigger conditions to achieve a certain logic function. Such as D triggers, t triggers, J-K triggers, R-S triggers, etc.. Simple triggers can also be implemented using separate electronic devices. There are many kinds of trigger modes, such as rising edge, falling edge, high level and low level.
第五， 继电器的触头容量一般不会超过5A，小型继电器的触头容量一般只有1A或2A，而接触器的触头容量最小的也有9A;接触器的触头通常有三对主触头(主触头都是常开触头)另外还有几对辅助触头，而继电器的触头一般不分主辅;继电器的触头有时是成对设置的，即常开触头和常闭触头组合在一起，而接触器不成对设置;继电器针对特定的要求，会与其它装置组合设计成时间继电器、计数器，压力继电器等等，有附加功能，而接触器一般没有。
Fifth, the relay contact capacity is generally not more than 5A, the small relay contact capacity generally only 1A or 2A, and the contact of the contactor capacity but also the smallest 9A contactor; there are usually three main contact (main contacts are normally open contact) and several other auxiliary contacts of relay contact, and generally not the main and auxiliary relay contacts; sometimes it is arranged in pairs, which is normally open contact and normally closed contact together, and the contactor can be arranged in pairs; relay according to specific requirements, and other devices designed combination of time relay, counter pressure relay, etc., there are additional functions and no general contactor.
