What Is The Structural Principle Of The Aviation Plug?
The role of the aviation plug is very large. Have you heard about its principle? Today, I will introduce the structure and principle of aviation plug to you.
1. Electrical properties The main electrical properties of the connector include contact resistance, dielectric withstand voltage and insulation resistance.
1. Insulation resistance: It is an indicator to measure the insulation performance between the contact of the electrical connector and the contact and the shell, ranging from hundreds of mega euros to several giga euros.
2. Contact resistance: High-quality electrical connectors must have low and stable contact resistance. The contact resistance of the connector varies from a few milliseconds to tens of milliseconds.
3. The dielectric withstand voltage is also called the electric strength, which refers to the ability of the connector to withstand the rated test voltage between the contact parts or between the contact part and the shell.
Other electrical performance EMI leakage attenuation is the evaluation of the electromagnetic interference shielding effect of the connector, and the electromagnetic interference leakage attenuation is the evaluation of the electromagnetic interference shielding effect of the connector, which is generally tested in the frequency range of 100MHz~10GHz. For wireless coaxial connectors, there are also electrical indicators such as characteristic impedance, insertion loss, reflection coefficient, and voltage standing wave ratio (VSWR).
With the development of digital technology, in order to connect and transmit high-speed digital pulse signals, a new type of connector, the high-speed signal connector, has appeared. Therefore, in terms of electrical performance, in addition to characteristic impedance, new electrical indicators such as crossover, transmission delay, delay, delay, etc. have also appeared.
2. Environmental performance
Typical environmental properties include temperature, moisture, salt spray, vibration, shock, and more.
Internal temperature The maximum working temperature of the current connector is 200C (except for some high-temperature special connectors), and the minimum temperature is -65C. When the connector is working, the current generates heat at the contact point, causing the temperature to rise, so it is generally believed that the operating temperature should be equal to the sum of the ambient temperature and the temperature rise of the contact. Some specifications specify the maximum allowable temperature rise for the connector at the rated operating current.
Resistance to intrusion of moisture can affect connection H insulation performance and rust, melting metal parts. The certain damp heat test conditions are relative humidity of 90%~95% (98% according to the product specification), and the test time is at least 96 hours according to the product specification. The alternating damp heat test is more severe.
When the salt spray resistant connector works in an environment containing moisture and salt, the metal structural parts and the surface treatment layer of the contact part will cause electrical corrosion, which will affect the physical and electrical properties of the connector.
To evaluate the ability of electrical connectors to withstand this environment, a salt spray test is specified. Hang the joint on the temperature adjustment experimental box, spray a certain concentration of sodium chloride solution into the compressed air to form a salt fog atmosphere, and the exposure time is specified by the product specification for at least 48 hours. (William Shakespeare, Sodium Chloride, Sodium Chloride, Sodium Chloride, Sodium Chloride, Sodium Chloride, Sodium Chloride, Sodium Chloride, Sodium Chloride, Sodium Chloride, Sodium Chloride).
The contact part is the core part of the connector to complete the electrical connection function. A contact pair usually consisting of a hermaphroditic contact and a voice contact, well, the electrical connection is completed by the insertion of the two contacts. The hermaphroditic contact portion is a rigid part in the shape of a cylinder (round pin), square cylinder (square pin) or flat (plug). The sexual contact part is generally made of brass or phosphor bronze.
The voice contact part (Jack) is the core component of the contact pair, relying on the elastic structure, elastic deformation occurs when the pin is inserted, and the elastic force is in close contact with the hermaphroditic contact part to complete the connection. Jacks are available in various configurations, including cylindrical (split slot, retraction), tuning fork, cantilever (longitudinal slot), folded (longitudinal slot, 9 characters), box (square jack), hyperbolic spring jack, etc.
2. Insulation material Insulation material, also known as a base or insert, is used to ensure that the contacts are aligned with the desired location and spacing, and to ensure insulation between contacts and between contacts and the housing. Good insulation resistance, withstand voltage performance and processability are the basic requirements for selecting insulating materials to be processed into insulators.
A housing, also known as a housing, is a connector housing that provides mechanical protection for the internal insulating mounting plates and pins, provides alignment when plugs and receptacles are inserted, and secures the connector to the device.
4. Accessories Sub-structure accessories and installation accessories. Structural accessories, such as retaining rings, positioning keys, positioning pins, guide pins, connecting rings, cable clamps, sealing rings, seals, etc. Mounting accessories such as screws, nuts, screws, spring coils, etc. Most of the accessories have standard parts and common parts.
3. Basic performance of aviation plug
The basic performance of the connector can be divided into three categories: mechanical performance, electrical performance and environmental performance.
Mechanical properties Plug force is an important mechanical property in connection function. Plug force is divided into insertion force and extraction force (also known as separation force), which have different requirements. Relevant standards have provisions for maximum insertion force and minimum separation force. That is, from the viewpoint of use, the insertion force is small (ie, the insertion force LIF is low, and there is no insertion force ZIF). Too little separation force will affect the reliability of the contact.
Another important mechanical property is the mechanical life of the connector. Machine life is actually a durability indicator, which is called machine operation in the national standard GB5095. Taking one insertion at a time and subtracting one time as a cycle, it is judged whether the connector can correctly complete the connection functions such as contact resistance value after the designated plug cycle.
The plug force and mechanical life of a connector are related to the contact structure (positive pressure magnitude), the quality of the contact coating (coefficient of sliding friction), and the dimensional accuracy of the contact array (alignment).
The above is the principle and professional knowledge of aviation plug, I hope it can be helpful to everyone!
