Symbolic representation of relays
Release Time：
2022-10-26 15:15
Source：
The relay coil is represented in the circuit by a long box symbol, and if the relay has two coils, two long boxes are drawn side by side. At the same time, mark the relay word symbol "J" in or beside the long box. There are two ways to represent the contacts of relays: one is to draw them directly on one side of the long box, which is more intuitive. The other is to draw each contact into its own control circuit according to the needs of the circuit connection. Usually, the contact of the same relay and the coil side are marked with the same text symbol, and the contact group is numbered to show the difference.
There are three basic forms of relay contacts:
(1) Dynamic closing type (normally open, H type) coil is not energized when the two contacts are disconnected, energized after the two contacts closed. It is represented by the pinyin prefix "H" of the word "he".
(2) dynamic break type (normally closed, D type) coil is not energized when the two contacts are closed, energized after the two contacts disconnected. It is represented by the phonetic prefix "D" of the character "duan".
(3) The conversion type (Z type) is the contact group type. There are three contacts in this contact group, that is, moving contacts in the middle and static contacts in the upper and lower. When the coil is not energized, the moving contact is disconnected from one of the static contacts, and the other is closed; After the coil is energized, the moving contact moves, so that the original disconnected state is closed, the original closed state is disconnected, to achieve the purpose of conversion. Such a group of contacts is called a transition contact. It is represented by the pinyin prefix "Z" of the word "Zhuan".
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