The relay intermediate, its structure and purpose of
Today the subject of our analysis will be such a device as an intermediate relay (hereinafter RP). This switching device is widely used in protection circuits, alarm and control. Let's get acquainted with this very useful product closer.
Content
Why do I need a device
product device
How does an intermediate relay
conclusion
Why do I need a device
First, let's understand the purpose for which it is necessary to relay. RP serves for: the switching control signals, the control powerful devices operate galvanically isolated power and control circuits, as well as the function of the signal coming reproduction.
Note. The relay was so called because in the control and automation circuits is always placed between the source of the control pulse and the executive power circuits.
product device
Despite all the variety of modifications, intermediate relay consists of the following components:
Electromagnetic coil, magnetic, spring-type mechanism and a group of contacts (from one pair to ten pairs).
Voltage relays can be designed for voltages between 12 V to 220 V. In this case, it can be both permanent and variable.
Externally, the relay is practically nothing indistinguishable. You can certainly try to see how to perform a magnetic core and its implementation has to determine the DC or AC voltage.
If he is recruited from separate plates, then before us a product that is designed to work with AC voltage, and if the magnetic piece, then we have a product that runs on a constant current.
But the easiest way to find this information by looking at the label on the cover or directly on the coil.
In terms of technical characteristics of intermediate relays of various types and performance have a different set of parameters.
Intermediate relay rated maximum current of 10 A.
Just now actively produced intermediate relay for mounting on Din-rail
How does an intermediate relay
Relay all models operate on the same principle, namely:
When a voltage appears on the control coil generated magnetic flux attracts the plate which is associated with a group of contacts, which thereby change their position (there is a disconnection, the closure of contacts).
Where to use the RP
The spectrum of application of these switching devices is very wide, you can see them in the boiler rooms, control rooms, substations, and so on. D. They have almost all control circuits, power, protection, alarm, etc.
For example, look at the input protection circuit of T-101 at one of the substations:
Or here's an induction motor control circuit:
conclusion
Intermediate relay is an important and integral part of most power control circuits. A wide variety of such products suggests that a switching device is able to perform a huge number of functions in full in any existing scheme. If the article is to provide you with interesting and useful, you will appreciate it. And thank you for your attention!