this article mainly introduces the role and wiring method of the intermediate relay, intermediate relay (intermediate relay): used in relay protection and automatic control system to increase the number and capacity of contacts. it is used to pass intermediate signals in the control circuit. the traditional intermediate relays and contactors are essentially based on the basic principle of electromagnets, which realizes the isolation and amplification control of small currents and large currents. there is no difference between the relays and the contactors in principle. the following is a detailed explanation of the role of relays. with the wiring method.
first, the role of the intermediate relay
the intermediate relay works like the ac contactor. it consists of a fixed iron core, a moving iron core, a spring, a moving contact, a static contact, a coil, a terminal block and a housing. when the coil is energized, the moving iron core acts to move under the action of electromagnetic force, and the moving contact is actuated to make the normally closed contact separate, and the normally open contact is closed; when the coil is powered off, the moving iron core drives the moving contact under the action of the spring. reset.
in the control lines of modern industrial or household appliances, intermediate relays are often widely used. for different control lines, its role will be different. what is the role of intermediate relays? in fact, the role in the line common ones can be divided into the following situations:
1, the intermediate relay can replace the small contactor
the contacts of the intermediate relays have a certain load capacity and can be used in place of small contactors when the load capacity is small. especially in the control of electric rolling shutters and small household appliances, it is characterized in that it not only plays a controlling role but also has certain advantages in the saving of the installation space, and at the same time allows the control part of the electric appliance to be relatively refined.
2, the intermediate relay can increase the number of contacts
i believe this practice is also common in circuit control, especially when there is only one contactor, how to control multiple contactors or other components? add an intermediate relay to the line to solve the problem. problem.
3, the intermediate relay can increase the contact capacity
it should be noted that although the contact capacity of the intermediate relay is not particularly large, it has a certain load capacity and the current required for driving is small, such as the inability to directly use the sensor switch or when the output of the triode is used to control the relatively large electrical components of the load, we can use the intermediate relay as the medium to expand the contact capacity.
4, the intermediate relay can convert the contact type
these conditions often occur in industrial control lines. the control process requires the use of normally closed contacts of the contactor to achieve control purposes. since the normally closed contacts of the contactor itself have been used up, complete the control work. at this time, the intermediate relay and the original contactor coil can be used for parallel connection. the principle is that the normally closed contact of the intermediate relay can control the corresponding component to reach the conversion contact type, so that the control task can be smoothly completed.
5, the intermediate relay can be used as a switch
it is necessary to know that in a part of the control circuit, the opening and closing action of the electrical component needs to be completed by the intermediate relay, that is, the opening and closing of the contact is used to realize the control. among them, the color tv and the automatic degaussing circuit commonly used in the display, the triode inside controls the on and off of the intermediate relay, and at the same time plays the role of controlling the on/off of the degaussing coil.
6, the intermediate relay can convert voltage and eliminate circuit interference
although there are many kinds of protection and anti-interference measures in industrial control and computer control lines, this kind of interference phenomenon still exists somewhat.
second, the intermediate relay wiring method and wiring diagram
since there are many types of relays and different uses, there are also some differences in the wiring. next, we mainly talk about the wiring method of the intermediate relay with 8-bit terminals. first, the corresponding parameters can be made and wired according to the serial numbers in the following wiring diagram:
1, wherein the serial numbers 5 and 6 represent a pair of common terminals;
2, and 1 and 2 represent a pair of normally closed contacts;
3. at the same time, 3 and 4 are a pair of normally open contacts;
4. in the state where 7 and 8 are not energized, 5, 6 and 1, 2 are turned on, and when the power is on, 1 and 2 are disconnected, but 5 and 6 at this time are not disconnected. 3, 4 is turned on.
in the intermediate relay wiring step, in the absence of a multimeter, how do we confirm the relay's power supply coil? here are some tips. there is an indication on the relay base. the direction of the arrow is the control direction, and the direction without the arrow is the coil direction. the role of the intermediate relay and the wiring method are here, i hope to help you.