September 11, 2019
4, the use of voltage
When the voltage used reaches a certain threshold, the contact film layer is broken down, and the contact resistance is rapidly lowered. However, due to the thermal effect, the chemical reaction in the vicinity of the film layer is accelerated, and the film layer has a certain repairing effect. The resistance is then nonlinear. In the vicinity of the threshold voltage, small fluctuations in the voltage drop cause the current to vary within a range of twenty or ten times. The contact resistance changes a lot, and if you don't understand this, you will get an error when testing and using the contacts.