Precautions for switch selection

In the process of selecting a switch, in addition to paying attention to the circuit type, we also need to consider some other specification parameters. The following are some common issues:

• Current and voltage: There are many types of switches on the market, and the rated voltage and current range of switches is very wide, from a few volts and a few amperes to hundreds or even thousands of volts and amperes. Developers must verify whether the switch can meet the expected rated current and voltage. For example, some air coolers only require 8A current, while others require 16A or even 20+A current. The price of different current switches will also vary, and the lower the current, the cheaper the switch will be.
• Material: Switch materials are divided into plastic and metal, etc. Many switches look the same in appearance but have a large price difference. This is because different materials are used, such as nylon, which is divided into single and double materials. Switches made of double nylon will be more fireproof and flame-retardant.
• Size: Switches come in various shapes and sizes. There are switches that are smaller than rice grains, as well as switches that are too large to be moved by hand. The size of the switch chosen usually depends on the designer's expected space size for the product. For example, portable small fans require switches with the smallest possible size.
• Default state: Most switches do not have a predetermined state, but some momentary switches typically exhibit a pre-set state, namely normally open (NO) or normally closed (NC).
• Installation: Like other electronic components, switches also have multiple installation configurations. Some are fixed by nuts, some are installed by screws, and some are soldered to circuit boards. How to install and power on also depends on the design of the developer.