Mechanical Performance Parameters of Circular Connectors

Circular connector pin separation force and total separation force

The contact pressure in circular connectors is an important indicator that directly affects the size of the contact resistance and the amount of contact point wear. In most structures, directly measuring contact pressure is quite difficult. Therefore, the contact pressure is often indirectly calculated by means of single-pin separation force.

For circular pin contact points, a standard plug pin with a specified weight is usually used to test the ability of the female connector to hold the weight of the male connector. Generally, the diameter of the standard plug pin is the minimum of the male connector diameter minus 5μm. The total separation force is usually twice the upper limit of the single-pin separation force. When the total separation force exceeds 50N, manual insertion and removal becomes quite difficult.

Of course, for some testing equipment or certain special requirements, zero insertion force connectors, automatic disconnect connectors, and so on can be used.

Mechanical life of circular connectors

The mechanical life of circular connectors refers to the plug-in life, usually specified as 500 to 1000 times. When the specified mechanical life is reached, the contact resistance, insulation resistance, and withstand voltage of the circular connector should not exceed the specified value.

Strictly speaking, the current mechanical life is a fuzzy concept. The mechanical life should have a certain relationship with time. The situation of using 500 times in 10 years is obviously different from using 500 times in 1 year. However, there is currently no more economical or scientific method to measure it.

Number of contact points and pinhole properties of circular connectors

The number of contact points can be selected according to the needs of the circuit, while considering the volume of the circular connector and the size of the total separation force. The more contact points, the larger the volume and the relative total separation force. In some cases where high reliability is required and the volume is allowed, the method of parallel connection of two pairs of contact points can be used to improve the reliability of the connection.

In the plug and socket of the circular connector, male connector pins and female connector sockets can generally be interchanged and assembled. In actual use, the choice can be made according to the charged situation at both ends of the plug and socket. For example, if the socket needs to be always charged, a socket with female connector sockets can be selected, because the charged contact is buried in the insulator and is not prone to touch by the human body, which is relatively safe.

Vibration, shock, and collision of circular connectors

Mainly considering the electrical continuity of the contact points of circular connectors when subjected to prescribed frequency and acceleration conditions of vibration, shock, and collision. The contact point will experience instantaneous disconnection under dynamic stress conditions. The prescribed instantaneous interruption time is generally 1μs, 10μs, 100μs, 1ms, and 10ms. It should be noted how to judge the occurrence of momentary interruption faults in the contact points.

Now it is generally believed that when the voltage drop across the closed contact points exceeds 50% of the electromotive force of the power source, it can be judged that a fault has occurred in the closed contact points. That is to say, judging whether momentary interruption has occurred has two conditions: duration and voltage drop, both of which are indispensable.