If the use of waterproof lightly touch switch contact bad situation should be dealt with in time, what is the specific treatment method? Below for you to better introduce, improve the handling of these problems.
Some of the water-proof lightly touch switches are broken inside, but the sections are still touched together. So it is still conductive from outside. But the length of such contact is often unreliable. Because, after the break, the cross-section enlarges, there are many bumps and bumps. When contacting again, there is a slight displacement (according to the description above, I think you have been deeply impressed by "moving"). Those bumps and bumps can not match the ocean when broken, so the contact area is greatly reduced. In contact, the pressure between surfaces is very small (just "bump" together). As a result, this kind of surface contact is good, and when the external effect reaches a certain level, one day the bottom of the road will be withdrawn. For example, multi-layer patch ceramic capacitors, sometimes installed on PCB, are cracked under thermal and mechanical stresses. Sometimes, these cracks cause dislocation between layers and layers of electrodes, resulting in short circuit capacitance. However, sometimes these cracks occur, the displacement between the layers is not large, and the electrodes of the layer and the layer are still connected between the sections. At this time, the capacitance shows neither short circuit nor open circuit. In this case, it is very difficult to test the problem, because the product may flow to the passenger side. However, this kind of capacitor has great hidden danger. One day, under the influence of various external factors, this kind of capacitor will become open circuit or interlayer short circuit. If you understand the above theory, you will be able to understand the topic.
In addition, the thermal expansion and contraction between the lightly touched switch devices will also affect the contact surface, making it force or deformation. In addition to the change of ambient temperature, the burning of the machine itself will also cause the change of the internal temperature of the machine. Exercise is absolute. All these changes and movements are constantly affecting the condition between the contact surfaces. On the surface, people think that these devices are not "moving", but in fact, there are external factors constantly acting on these contacts, and the contact conditions of the contacts have undergone "surging" changes.
For example, some people say that if I did not touch the device, how could it go from good contact to bad contact (or bad contact to good contact, where "good" and "bad" actually refer to small contact resistance or even open circuit)? Generally speaking, "no touch" refers to not touching the device directly. As a result, many people assume that there is no new external force on the device, so the contact state should not be changed. What's the truth? Let's assume that a device is mounted on a finished product and that the finished product is on a table. At this time, the device is in a static state, it must be out of the force balance state. Then, someone picked up the finished product. At this time, did the device inside receive any new external force? I can tell you with great certainty that I have been subjected to new external forces. In a very short time, the device changes its state of motion from stationary to moving, so it must be affected by new external forces. Anyone with a slight physical foundation can understand the subject. Since the device is subjected to a force, it is possible to reactivate, deform or displace the contact surfaces. Therefore, the previous contact state may change. We will recall the theory mentioned above that the contact between metal surfaces is an interlaced contact of uneven canine teeth, at the same time, these surfaces also have oxide layer and impurities. If the previous contact happens to be at the critical point of good (or bad) contact, let's think about how many possibilities have changed. One is to become more out of touch or more out of touch. All this depends on these three factors:
1. Surface concavity and convexity, distribution of oxides and impurities;
2. Initial contact state;
3. Direction of force or deformation (or displacement). There are countless possibilities for any of these three factors. Therefore, there are countless possibilities for the consequences of external forces. It's like changing from bad contact to good contact, or from good contact to bad contact. Of course, it is also possible that poor contact after external force is still bad, good contact after force is still good. It is also possible that the surface in good (or bad) critical contact state will sometimes get better and sometimes worse after constant action. Of course, sometimes this change is irreversible under general action. For example, in the past, when the contact was bad, after the action of external force, many concave-convex contacts happened to coincide with each other. Then, because of the bite between concave-convex contacts, they still had a good occlusion, because of the general external force, they still had a good occlusion. Of course, if the pressure between these contacts is not enough, and there are more impurities, then even if the contact is not good in a short time, it will become bad in a long time and various factors continue to play a role, one day it may become bad in contact.
When metal contacts, if there is a significant external force, the contact condition changes, we can easily understand. For example, when the connector contacts badly, it may be good to press it by hand. Some devices have poor internal contact, vibrate or knock on this.
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