Because the metal conductor terminal is easy to produce instant heating and sparks at the moment of contact, prompting its contact point in the use of multi-frequency process, easy to produce oxidation and electrolysis, so the contact point is increased and thickened, or the use of polymer metal manufacturing (with copper and silver two materials), so the contact point made of polymer metal, or the same material The thickened points are called silver contacts.
A silver contact is a switch that uses metal contacts to open or close a circuit, turn off current, or divert it to other circuits. In the field of silver contact, it is generally divided into pure silver contact, silver-nickel alloy contact, silver-tin oxide contact, silver-cadmium oxide contact.
However, the switch industry has a certain scale of production enterprises and application enterprises generally know how to choose silver contacts to ensure the quality and life of the switch, and many small and medium-sized enterprises lack understanding of silver contacts.
Silver-cadmium oxide and silver-nickel alloy contacts are widely used in the switching industry, but how much do you know about their proportions and production processes? Silver nickel 10, 12, 15? Or silver nickel 20? Is it silver cadmium oxide or silver cadmium?
Silver contact
Therefore, many switchgear factories blindly compress costs or some small silver point manufacturers with special processes to reduce costs to obtain profits, the people in this small series of switches, have the obligation to give us a simple promotion of the switch industry, the silver cadmium oxide contact.
Ratios can be verified by a third party (metal composition analysis), but the process is difficult to control. Maybe some of the silver spots aren't oxidized at all. It depends on how you choose the silver contact manufacturer.
In the energized state, when the dynamic and static contacts are out of contact, if the current of the broken circuit exceeds a certain value (different relay contact materials are different, and the rated current is different), or the voltage at both ends of the contact gap exceeds a certain value (different relay contact materials are different, and the rated voltage is different), an arc will occur in the contact gap. The arc is actually the discharge of gas between the contacts under a strong electric field, which produces high temperature and emits strong light and sparks. The existence of arc, not only burns the metal surface of the contact, reduces the life of the appliance, but also extends the breaking time of the circuit, and even causes relay contact failure, which will cause fire or gas accidents in serious cases. Therefore, in order to accurately detect the change law of contact pressure, it is necessary to ensure that during the experiment, the current broken by the electromagnetic relay and the voltage applied at both ends of the relay contact cannot exceed the rated value.
