[system integration] aviation plug

Aerial plug

The air plug is an electromechanical component that connects the electrical lines, so the electrical parameters of the air plug itself are the first consideration of choosing the air plug. The correct choice and use of aviation plugs is an important aspect to ensure the reliability of the circuit.

Parameter requirement

1 、 rated voltage

Rated voltage, also known as the working voltage, it mainly depends on the insulation used by the aviation plug, contact between the size of the gap. Some components or devices may not perform their intended function when they are below their rated voltage. The nominal voltage of an air plug shall in fact be understood as the highest operating voltage recommended by the manufacturer. In principle, the air plug works properly below the rated voltage. In general, according to the pressure (electrical strength) index of the air plug, the rated voltage shall be used reasonably according to the use environment and the safety grade. That is to say, the same voltage resistance index, according to the different use environment and safety requirements, can be used to different maximum working voltage. This is also in line with the objective use.

2 、 rated current

Rated current, also known as working current. Same as the rated voltage, the air plug works normally when the rated current is lower than the rated current. In the design process of the aviation plug in, through the thermal design of the aviation plug to meet the requirements of the rated current, because of the exposure to current flows, due to the presence of conductor resistance and contact resistance, the contact will be fever. When its heating exceeds a certain limit, it will destroy the insulation of the air plug and form the softening of the coating on the surface. Therefore, to limit the rated current, in fact, to limit the temperature of the internal air plug does not exceed the design requirements. In the choice, pay attention to the problem is: for multi-core aviation plug, the rated current must be reduced to use.

3. Contact resistance

Contact resistance is the resistance produced by two contact conductors in the contact portion. In the selection, we should pay attention to two problems. First, the contact resistance index of the air plug is in fact a contact resistance, which includes contact resistance and contact resistance to the conductor. Generally, conductor resistance is small, so contact resistance is called contact resistance in many technical specifications. In second, the small signal circuit connection, should pay attention to the contact resistance index is given is under what conditions, because the contact can be attached to the surface of the oxide layer, oil or other pollutants, the two contact surface will produce corrosion resistance. When the thickness of the film increases, the resistance increases rapidly, and the film becomes a bad conductor. However, the film will undergo mechanical breakdown at high contact pressure, or electrical shock will occur at high voltage and high current. For some small volume connector design contact pressure is quite small, the use of occasions only for mA and mV level, film resistance is not easy to be broken down, may affect the transmission of electrical signals.

4, shielding

In modern electrical and electronic equipment, the density of components and the increasing correlation between them make strict restrictions on electromagnetic interference. Therefore, the air plugs are often enclosed with metal shells to prevent internal electromagnetic radiation or interference from outside electromagnetic fields. At low frequencies, only magnetic material can shield the magnetic field. At this point, the electrical continuity of the metal shell is specified, that is, the contact resistance of the case.

5, installation and shape: the installation of air plugs installed before and after installation, installation methods include rivets, screws, clamping ring or air plug itself, card pin, fast locking, etc.. There is also a plug and socket are free end air plug, that is called the "plug" air plug.

6, environmental parameters: environmental parameters are temperature, humidity, temperature change, atmospheric pressure and corrosive environment. The environment in which the electrical connector is used, stored and transported has a significant influence on its performance, so the corresponding air plugs must be selected according to the actual environmental conditions. In addition, the metal material and the insulation material of the air plug determine the working temperature of the electrical connector. High temperature will destroy the edge material, resulting in insulation resistance and resistance to lower performance; for metal, high temperature can make contact lose elasticity, accelerate oxidation and coating deterioration.