How to choose microswitches?

Microswitches are mainly used for mechanical control, so the requirements for the type, stroke, and action force of switch actuating components should be stricter. So how do we choose microswitches? Today, Shanghai Yongxing Electronics will share with you

One is that the operating characteristics of microswitches will change with the increase of switching times during the load on/off process, and the magnitude of this change is called the stability of the operating characteristics. Sometimes, although the mechanical components and switches themselves are not damaged, control errors occur in the control system, which is caused by changes in the action characteristics. When selecting microswitches, users should not only pay attention to the load, but also consider leaving a certain safety factor for the operating characteristics, or using switches that self compensate for the operating characteristics.

The second is that the overtravel of the microswitch is designed to ensure reliable contact and prevent poor repetition accuracy of the action points. But if the overtravel is too large, it will increase the deformation of the internal spring system. As the usage time and frequency increase, the stability of the action characteristics will quickly deteriorate, and the service life of the microswitch will also be greatly shortened. Therefore, it is better to use an overtravel that is one-third of the total length of the product's overtravel.

Thirdly, when using microswitches, users are not allowed to add other transmission mechanisms on their own.

Fourthly, the installation of microswitches must be carried out according to the dimensions specified in the product manual or standard. The installation screws, bolts, shaft pins, etc. of microswitches should not be made thinner or thicker, as thinning may cause shaking and affect the operating characteristics, while coarsening may damage the switch substrate due to hole expansion.

Fifth, users should not install additional devices or modify switches separately, otherwise it will affect the operating characteristics of the microswitch.

The welding time of the welding terminal should not exceed 3-8 seconds, and the temperature should not exceed 260 ℃. Otherwise, it will be scrapped due to overheating during welding, burning the substrate or causing solder to penetrate into the interior of the switch, affecting insulation performance, contact performance, and action characteristics. Corrosive zinc chloride shall not be used as flux. The general specification for microswitches is GJB 809A-1997 "General Specification for Microswitches".