The mechanical parameters of the connector include:
(1) Single leg separation force and total separation force. The contact pressure in the connector is an important indicator, which directly affects the size of the contact resistance and the wear of the contact pair. In most structures, direct measurement of contact pressure is quite difficult. Therefore, contact pressure is usually measured indirectly by the separation force of a single leg. For round pinhole contact pairs, standard pins with specific weights are often used to test the ability of the female contacts to withstand the weight. Normally, the diameter of a standard pin is the lower limit of the male contact diameter-5 μm. The total separation force is usually twice the sum of the lines on the one-leg separation force. When the total separation force exceeds 50N, it is already difficult to manually insert and remove. Of course, for some test equipment or some special requirements, zero insertion force connectors, automatic disassembly connectors, etc. can choose.
(2) Mechanical life. The mechanical life of the connector refers to the plug-in life, which is usually specified as 500-1000 times. The connector produced by McConnell Electronics can be inserted and removed 3,000-5000 times. When the specified mechanical life is reached, the contact resistance, insulation resistance and withstand voltage of the connector must not exceed the specified values. Strictly speaking, the current mechanical life is a vague concept. Mechanical life should have a certain relationship with time. 500 times in 10 years is significantly different from 500 times in 1 year. However, there is no more economical and scientific way to measure it.
(3) Number of contact pairs and pinholes. First, the number of contact pairs can be selected according to the needs of the circuit, taking into account the size of the connector and the total separation force. The number of contact pairs is large, of course, its volume is large, and the total separation force is relatively large. In some cases with high reliability requirements and allowable volume, two pairs of contact pairs can be connected in parallel to improve the reliability of the connection. In the plug and socket of a connector, pins (male contacts) and sockets (female contacts) are usually interchangeably assembled. In actual use, you can choose according to the live condition of the plug and the socket. If the socket needs to be charged normally, you can choose a socket with a socket, because the live contact piece with the socket socket is buried in the insulator, and the human body is not easy to touch the live contact piece, which is relatively safe.
(4) Vibration, shock and collision. The main consideration is the electrical continuity of the contact pairs during connector vibration, shock and impact at specific frequencies and accelerations. Under this dynamic stress condition, the contact pair will open instantly. The specified instantaneous disconnection time is generally 1 μs, 10 μs, 100 μs, 1 ms and 10 ms. It should be noted how to judge the instantaneous failure of the contact pair. It is now generally believed that when the voltage drop across the closed contact pair (contact) exceeds 50% of the power electromotive force, it can be determined that the closed contact pair (contact) has failed. That is, there are two conditions for judging whether a transient occurs: duration and voltage drop, both of which are indispensable.