Full analysis of the role, structure and working principle of the guide rail intermediate relay ---- linhao power technology
Full analysis of the role, structure and working principle of the guide rail intermediate relay
The role of the rail intermediate relay
The general circuit is often divided into two parts: the main circuit and the control circuit. The relay is mainly used for the control circuit and the contactor is mainly used for the main circuit. The relay can realize the function of controlling one or several signals with one control signal, and completing the start and stop. And linkage control, the main control object is a contactor; the contactor has a large contact and a strong carrying capacity. It can be used to control weak to strong electricity, and the control object is an electrical appliance.
Rail intermediate relay components
The guide rail intermediate relay is a relay. Its principle is the same as that of the AC contactor. It is composed of a fixed iron core, a moving iron core, a spring, a moving contact, a static contact, a coil, a terminal and a housing.
Rail intermediate relay working principle
The coil is energized, and the moving iron core moves under the action of electromagnetic force, which drives the moving contact to separate the normally closed contacts and close the normally open contacts. When the coil is powered off, the moving iron core drives the moving contacts under the action of the spring. Reset, the working principle of the relay is that when a certain input quantity (such as voltage, current, temperature, speed, pressure, etc.) reaches a predetermined value, it is caused to act to change the working state of the control circuit, thereby achieving the intended control or protection. purpose. In this process, the rail intermediate relay mainly plays the role of transmitting signals.
What is the difference between a rail intermediate relay and an AC contactor?
The rail intermediate relay is a relay. Its principle is the same as that of the AC contactor. It is composed of a fixed iron core, a moving iron core, a spring, a moving contact, a static contact, a coil, a terminal and a housing. The coil is energized, and the moving iron core moves under the action of electromagnetic force, which drives the moving contact to separate the normally closed contacts and close the normally open contacts. When the coil is powered off, the moving iron core drives the moving contacts under the action of the spring. Reset.
In the industrial control circuit and the current home appliance control circuit, there are often rail intermediate relays. For different control circuits, the role of the rail intermediate relay is different. The common functions in the circuit are as follows:
1.Replaces small contactors
The contacts of the rail intermediate relay have a certain load capacity. When the load capacity is relatively small, it can be used instead of small contactors, such as the control of electric rolling shutters and some small appliances. This has the advantage that it can not only achieve the purpose of control, but also save space and make the control part of the appliance more delicate.
2. Increase the number of contacts
This is a common usage of the rail intermediate relay. For example, when a contact of a contactor in a circuit control system needs to control multiple contactors or other components, a rail intermediate relay is added to the line.
3. Increase contact capacity
Although the contact capacity of the rail intermediate relay is not very large, it also has a certain load capacity, and at the same time the current required for its drive is very small. Therefore, the rail intermediate relay can be used to expand the contact capacity. For example, the output of inductive switches and triodes cannot generally be used to control electrical components with relatively large loads. Instead, the rail intermediate relay is used in the control circuit, and other loads are controlled by the rail intermediate relay to achieve the purpose of expanding control capacity.
4. Conversion contact type
In industrial control circuits, this often happens. The control requires the use of the normally closed contact of the contactor to achieve the control purpose, but the normally closed contact of the contactor itself has been used up and the control task cannot be completed. At this time, a rail intermediate relay can be connected in parallel with the original contactor coil, and the normally closed contact of the rail intermediate relay is used to control the corresponding components, and the contact type is switched to achieve the required control purpose.
5.Used as a switch
In some control circuits, the on-off of some electrical components often uses guide rail intermediate relays, which are controlled by the opening and closing of their contacts. Control the on-off effect of the degaussing coil.
6. Eliminate interference in the circuit
Although there are various interference suppression measures in industrial control or computer control lines, the interference phenomenon still exists more or less.