Especially important requirement is that the electrical connector must reach good contact, reliable work, convenient maintenance, its working reliability directly affects the normal operation of the aircraft circuit, involving the safety of the whole host machine. For this reason, the host circuit has very strict requirements on the quality and reliability of electrical connectors, which is also widely used in aviation, aerospace, defense and other military systems due to the high quality and reliability of electrical connectors.
1. Contact resistance refers to the resistance generated by two contact conductors in the contact part.
2. Two problems should be noted in the selection. First, the contact resistance index of the electrical connector is actually the contact resistance, which includes the contact resistance and the contact resistance to the conductor. Generally, conductor resistance is small, so contact resistance is called contact resistance in many technical specifications.
3. Second, in the circuit connecting small signals, it is important to pay attention to the conditions under which the contact resistance indicators given are tested, because the contact surface will be attached with an oxidation layer, oil or other pollutants, and the two contact surfaces will generate film resistance.
4. When the thickness of the film layer increases, the resistance increases rapidly, making the film layer become a bad conductor. However, mechanical breakdown may occur in the membrane under high contact pressure, or electric breakdown may occur under high voltage and large current.
5. The contact pressure of some small size electrical connectors is quite small, and the service occasions are only mA and mV levels. The resistance of the film layer is not easy to be broken, which may affect the transmission of electrical signals.
6, in GB5095 "regulations of electricity in the basic test equipment with mechanical and electrical components and measuring method of contact resistance test method is one of the contact resistance, millivolt method" regulation, in order to prevent contact with pieces of the insulating film is punctured, the test circuit shall not open circuit electromotive force of dc or ac peak more than 20 mv, dc or ac test current should be not more than 100 ma. In fact, this is a low level contact resistance test method, therefore, there is a choice of this requirement, because the low level contact resistance indicators are chosen by the connector.