Intermediated Relay: For relay protection and automatic control systems to increase the number and capacity of the contact.It is used to pass the intermediate signal in the control circuit.The structure and principle of the intermediate relay are basically the same as the AC contactor. The main difference between the contactor is that the main contact of the contactor can pass through large current, and the contact of the intermediate relay can only pass the small current.Therefore, it can only be used to control the circuit.It generally does not have the main contact, because the overload capacity is relatively small.Therefore, all it uses is auxiliary contacts, with a large number.New national standard to the middle
Intermediate relay wiring
Different relay wiring methods will be different.The following is the wiring method of 8 wiring terminals.5 and 6 are a pair of public terminals, 1 and 2 are a pair of normally closed contacts, and 3 and 4 are a pair of frequent opening contacts.7, 8 When power is not powered, 5-6 and 1-2 are connected, and 1-2 will be disconnected after power -on, and 5-6 continues, and then connected with 3-4.Generally, the intermediate relay is a double -knife and double throw switch. The 7-8 terminals connect the internal coils. When used, a diode can be connected in parallel.7- The positive electrode of the second-level tube), when the predetermined value is reached, the relay will work to drive the circuit to disconnect. At that moment, it will generate a high current due to the self-sensing voltage.It does not pass the circuit, which protects the components in the circuit.
Intermediate relay model
Intermediate relay symbol
1. Electromagnetic intermediate relay This relay is a coil connected to the circuit, which is based on the strength of the coil current.This relay is characterized by a small number of coil wires and less coil impedance.The relay coil is represented by a rectangular frame symbol in the circuit graphics. If the relay has two coils, two side -in -side boxes are drawn.There are two ways to express electromagnetic relay contacts. One is to directly draw on the side of the rectangular frame, which looks more intuitive.Another more complicated, drawing each contact into each control circuit, respectively.2. The delayed intermediate relay delayed intermediate relay symbol is divided into power -powered delay and power -off delay. It also has a transient contact.There are frequent and normally closed contacts when power -on, and frequent and normally closed contacts during power off.It is easy to confuse when looking at these symbols.Looking closely, you will still find different places.
Intermediate relay working principle
The coil of the intermediate relay is installed on the U -shaped conductive magnet. There is a blockbuster on the conducting magnet. There are two rows of contacts on both sides of the magnetic magnet. In the non -motion state, the armed iron is lifted up, so that the armed iron and the magnetic conducting magnet are.Maintain a certain gap between the between when the electromagnetic torque between the air gap exceeds the reaction torque, the armed iron is inhaled to conduct the magnetic body, and at the same time, the armor pressure the contact shifts, so that the normal closed contact is disconnected from the frequent contact. You have completed the signal of the signal.transfer.
The role of intermediate relay
1. The contact of the small contactor 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 curls and some small appliances.This advantage is that not only the purpose of control can be played, but also can save space and make the control part of the appliances more delicate.2. Increasing the number of contacts. This is the most common usage of intermediate relay. For example, when the contact of a contactor in the circuit control system requires controlling multiple contactors or other components, adding an intermediate relay in the line.3. Increasing the connection capacity, we know that although the intermediate relays contact capacity is not very large, it also has a certain load capacity. At the same time, the current required for the driver is small, so you can use intermediate relay to expand the connection capacity.For example, generally cannot directly use the induction switch and the output of the triode to control the more electrical components with large loads.Instead, the intermediate relay is used in the control line, and other loads are controlled through the intermediate relay to achieve the purpose of expanding the control capacity.

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