Know the safety relay
Measure the coil of the relay. The coil should have a small resistance value under du. If the resistance value is infinite, it means that the coil is open and the relay is damaged.
When the coil is energized, the iron core is magnetized to generate a large enough electromagnetic force, which attracts the armature and drives the reed to close or separate the movable contact and the static contact; when the coil is de-energized, the electromagnetic attraction force disappears and the armature returns to its original position , The moving contact and the static contact are restored to the original closed or separated state. In application, as long as the circuit to be controlled is connected to the contact, the relay can be used to achieve the purpose of control.
1. Make correct selection. To make good use of relays such as CYNDAR relays, the correct selection is very important. First, you must have a thorough understanding of the nature, characteristics and use requirements of the controlled object, and careful consideration. The principle, use, technical parameters, structural characteristics, specifications and models of the selected relay should be mastered and analyzed. On this basis, the relay should be correctly selected according to the actual situation and specific conditions of the project.
2. Understanding of the contact point. The static and dynamic contacts that are in the disconnected state when the relay coil is not energized are called "normally open contacts", and vice versa, they are called "normally closed contacts". If a moving contact is normally closed with one static contact and normally open with another static contact at the same time, they are called "conversion contacts". In the same relay, there can be one pair or several pairs of normally open contacts or normally closed contacts (both can also have at the same time), and it can also have a set or array of conversion contacts.