The contactor is divided into AC contactor (AC) and direct current contactor (DC), which is applied to electric power, distribution and power. In general, the contactor refers to the magnetic field generated by the magnetic field of the coil current in the industrial electricity, so that the contact is closed to achieve the control of the load.
1 function 2 working principle
3 main structures 4 main classification
On the electrical engineering, because of the fast cut off AC and DC main circuit and
Frequently connected with the current control (some types of up to 800 Amperes) circuit device, so often used in motor do as the control object, can also be used to control factory equipment, electric heater, machine tools and all kinds of electric power unit and power load, contactor can not only connect and cut off the circuit, but also has the protective effect of low voltage release of. Contactor control capacity, suitable for frequent operation and remote control. Is one of the important components in the automatic control system.
In industrial electrical, the model of the contactor is a lot of electric current in the range of 5A-1000A, its use is quite extensive.
The working principle of the contactor is: when the contactor coil is energized, the coil current will produce a magnetic field,
The magnetic field generated by the static iron core to attract the magnetic attraction of the core, and to promote the exchange of contact point of the action, normally closed contact, often open contact closure, the two are linkage. When the coil power, the electromagnetic force disappears, the armature of the release spring release, make contact restoration, normally open contacts disconnect, normally closed contact is closed. The working principle of the DC contactor is somewhat similar to the principle of the temperature switch.
AC contactor to open and close circuit with main contact,
With auxiliary contacts to guide the control loop.
The main contact is normally open contact, and the auxiliary contact often two pairs of normally open contact and normally closed contact, small contactor is also often used as the intermediate relay with the main circuit.The contact of AC contactor, made of silver tungsten alloy, has good electrical conductivity and high temperature resistance.The power source of the AC contactor moves to the magnetic field generated by the iron core coil, the magnet core is made of two "mountain" - shaped silicon steel sheets, wherein a fixed iron core, a coil and a working voltage can be selected. In order to make the magnetic stability, pull side core plus short circuit ring. AC contactor is on the loss of power, relying on the spring reset.The other half is the active iron core, the structure and the fixed iron core, used to drive the main contact and auxiliary contact closure.
More than 20 amps contactor with arc shield, the circuit is disconnected from the electromagnetic force, fast breaking arc, the protection of contact.With a high frequency of operation, the highest operating frequency can be up to 1200 times per hour when the power is turned on and off.
The service life of the contactor is very high, the service life of the machine is usually ten million times.
AC contactor is made as a whole, and its appearance and performance are improved, but the function is always the same.
Regardless of the extent of the development of the technology, the ordinary AC contactor has its important status.Air type electromagnetic contactor（other name：Magnetic Contactor）：Mainly by the contact system, the electromagnetic operating system, support, auxiliary contacts and shell (or chassis).
Because the AC electromagnetic contactor coil commonly used AC power supply, after the excitation contactor, usually a high decibel "slightly" noise, which is the electromagnetic contactor characteristics.80 years later, the national study of the silent and power of the AC contactor electromagnet, the basic feasible solution is to turn the AC power supply with the transformer, and then converted into DC power supply, but this complex control mode is not much.
Vacuum contactor: vacuum contactor contactor contact system by vacuum chamber degaussing.
Semiconductor contactor: semiconductor contactor is a kind of circuit breaker by changing the state of the circuit and the circuit breaker to complete the current operation of the contactor.
Permanent magnet contactor: permanent magnetic AC contactor is using pole same-sex repulsion, opposites attract the principle, permanent magnet drive mechanism to replace the traditional electromagnet drive mechanism and the formation of a micro power contactors.
According to the main contact of the form of the loop is divided into: DC contactor, AC contactor.
According to the operation of the body is divided into: electromagnetic contactor, permanent magnetic contactor.Permanent magnetic AC contactor is the pole of same-sex repulsion, permanent magnet drive mechanism to replace the traditional electromagnet drive mechanism and the formation of a micro power consumption contactor domestic mature product model: