How to Choose Normally Open and Normally Closed Touch Switches
Release time：2019-01-14 Clicks： Click
There are two types of light-touch switches: normal open type and normal closed type, so we should choose them according to our own needs when choosing them, so as to avoid problems. Specific details are described in detail below.
The function of touch switch can be divided into two types: one is normally open type and the other is normally closed type. The most common type is the normal open type, which means that the line is generally disconnected, and the button handle is pressed to touch the shotpoint contact between the shrapnel and the base. At this time, the switch is considered to be on, and the shrapnel and the shotpoint are separated when the button handle is released. At this time, the switch is considered to be separate, and the product performance is OK. When the line is disconnected, the resistance of the two circuits is 30m ohm. When the switch is on, the contact resistance of the two circuits is 0. The performance of the switch is very good. Normally closed type is relatively rare, because it is not in line with the conventional product design. Normally closed type refers to the switch is on, when the switch is activated, the circuit and function are disconnected. The resistance value of this kind of switch is the opposite of that of normal switching, so it is generally not recommended to use.
Whether it is open or closed, the touch switch must consist of more than two pins, so as to form a set of switch functions, normally two feet, four feet and five feet. Why are there five-legged switches? Because the fifth foot is for grounding, I think you all know what the grounding foot is for. Of course, there are three feet, generally three feet are more lateral pressure, this third foot is designed for fixed, so you can rest assured that use, hard to press is no problem. The two-legged circuit in the figure below can be seen at a glance. Let me explain how the four pins of the light switch are connected. Normally, 1 and 2 are a group of switches, 3 and 4 are a group of switches, 1 and 3 are a group when the switch is touched, 2 and 4 are a group. It is right to design the function of the switch in this way.
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