Do You Know Where Key Switches Are Often Used?

With the development of technology and the improvement of our living standards, many appliances around us have been greatly improved. A key switch is a type of electronic switch, which is an electronic component class that has been upgraded from the original key switch. The key switch is widely used in many home appliances and electrical appliances because of its advantages of good feel, convenient operation and diversified specifications. Today let's take a look at how the key switch works.

Key switch introduction:

The key switch, also known as the key switch, first appeared in Japan [called: sensitive switch]. When it is used, the switch function is closed and turned on by applying pressure to the operation direction of the switch to meet the conditions of the operating force. The internal structure is connected and disconnected by the force change of the metal shrapnel. The key switch is composed of an insert, a base, a shrapnel, a button, and a cover plate. The waterproof key switch adds a layer of polyimide film on the shrapnel.

The key switch has the advantages of small contact resistance load, accurate operating force error, and diversified specifications. It has been widely used in electronic equipment and white goods, such as audio and video products, digital products, remote controls, communication products, and household appliances. , Security products, toys, computer products, fitness equipment, medical equipment, money detector pens, laser pen buttons and so on. Because of the environmental conditions of the key switch (elastic force with pressure less than 2 times/environmental temperature and humidity conditions and electrical performance), large equipment and high-load buttons are directly replaced by conductive rubber or dome switch hardware shrapnel, such as medical equipment, TV. machine remote control, etc.

The structure and use of the key switch

The key switch is divided into two categories: the key switch that uses the metal reed as the switch contact piece, the contact resistance is small, and the cluster is 20mn. Feels good, there is a "tick" crisp sound. A switch that uses conductive rubber as a contact path is habitually called a conductive rubber switch. The switch feels good, but the contact resistance is large, generally 100-300n. The structure of the key switch is to move down by the key, so that the contact reed or the conductive rubber block contacts the solder tab to form a path.

The operating force of the key switch is related to the state of the reed. The starting force is proportional to the distance the reed is compressed when the reed is compressed to 5. When the operating force is suddenly reduced from % to 70%, it is accompanied by a "tick" sound. Guide turtle rubber switch generally has two structures. The operating force curve varies greatly with the geometry of the rubber block.

Key switches are mainly used in color TV sets, black and white TV sets, audio equipment, video recorders, cameras, computers, game consoles, fax machines, walkie-talkies, batons, machine tool control devices, copiers, printers, electronic instruments, meters and other household appliances.

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Button key switch related size introduction

There are many sizes of key switches, among which, if the size is the same, it depends on the height of the key switches. Many key switches look the same, but the thickness (height) is different. Listed below are several of the most representative key switch sizes.

Among them, the 2x3 and 2x4 key switches are also called Xiaobei four-pin SMD key switches. His height is generally 3.5mm.

The 3x3 key switch has two main heights, 0.8 and 1.5 in height, and has three functions of environmental protection, high temperature resistance, and waterproof, mainly only the SMD key switch.

The size and height of 3x4 key switches are mainly 1.8, 2.5 and 3.0, and there are several key switch types: environmental protection type, double-shrapnel type, and two-foot patch.

The size and height of the 3x6 key switch mainly include: 0.8, 3.5, and 3.8. They belong to the side press series of key switches, with two-leg side press and four-leg side press.

The size and height of 4x4 key switches mainly include: 1.5, 1.7, 2.0, 2.3, 2.5, 3.0, 3.5, 3.7, 4.3, 6, and eight heights of SMD key switches, generally four-legged SMD keys.