Classification and characteristics of electrical contacts

Classification of electrical contacts
1, fixed contact: with fasteners such as screws or willow nails and other compressed electrical contact is called fixed contact, fixed contact in the course of work there is no relative movement.
2, can be divided into contact: in the course of work can be separated from the electrical contact can be divided into contact, also known as contact. Electrical contacts are always in pairs, one of which is a static contact, the other is a moving contact, contact closure in the spring when the general is pressed.
3, sliding and rolling contact: In the course of work, the contacts can slide or roll between each other, but can not separate the electrical contact is called sliding and rolling contact.

Electrical contact characteristics
With good resistance to electric wear, anti-welding, thermal conductivity, small contact resistance, due to the dispersion of cadmium oxide is the division, can increase the hardness of the material and improve the resistance to mechanical wear. In the short-circuit current through the anti-welding ability, electrical contact manufacturing process has a great impact on its performance. The electric contact made by powder metallurgy has good anti-welding property, and the single resistance to erosion is poor. The resistance of the electric contact made by alloy internal oxidation is good, but the cold resistance is lower.

Application of electrical contacts
Electrical contacts are widely used in relays, contactors, load switches, in the low-voltage circuit breakers and household appliances, automotive electronics (speakers, lights, ignition) and other electrical switching equipment, the main electrical contact material. Switching devices are widely used in the analysis / closed circuit voltage / current, its reliability directly affects the reliable operation of the entire power system, and electrical contacts is one of the important parts of the switchgear.