A three pin touch switch is a press type electronic switch with three pins that controls the on/off of circuits through external pressure. It is widely used for button operation in electronic devices such as remote controls, small appliances, and instrument panels. The main features and advantages are as follows:
1、 Main features
Three pin structure, flexible functionality
It includes three pins: common terminal (COM), normally open terminal (NO), and normally closed terminal (NC). When not pressed, the common terminal is conductive with the normally closed terminal, and when pressed, the common terminal is conductive with the normally open terminal. The wiring method can be flexibly selected according to the circuit requirements (such as "press on" or "press off"), and it is suitable for multiple control logics. Compared with the two foot touch switch (only with a single on/off function), it has a wider applicability.
Self resetting feature, easy to operate
Relying on the elasticity of internal metal shrapnel to achieve automatic reset: the contact switches when pressed, and immediately returns to the initial state after release, without the need for manual reset. The operation is simple and suitable for scenarios that require "instant triggering" (such as remote control buttons and instrument panel function keys).
Miniature design, suitable for compact spaces
Compact in size (common sizes 6 × 6mm, 12 × 12mm, etc.), low in height (usually 5-10mm), can be directly mounted or plugged onto circuit boards, saving installation space and meeting the design needs of electronic devices for miniaturization and lightweight (such as smartwatches, microcontrollers).
No locking function, relying on continuous pressing
It only maintains the on/off state when pressed, and automatically recovers after release. It belongs to a "jog switch" and does not have the ability to latch (maintain state). It needs to be coordinated with external circuits (such as microcontrollers and triggers) to achieve continuous control and avoid state disorder caused by misoperation.
Reliable contact and long lifespan
Internally, metal spring plates (such as silver plated brass) are used as contacts, with low contact resistance (≤ 50m Ω) and stable conductivity; High quality models can achieve a pressing life of 100000 to 1 million times by optimizing the material and structure of the shrapnel, meeting long-term frequent operation needs.
2、 Core advantages
Functional diversity, adaptable to complex circuits
The three pin design allows for the implementation of two switching logics, "normally open" and "normally closed", and can be directly connected to circuits that require reverse control (such as safety protection circuits for "press stop, release start"), without the need for additional reverse components, simplifying circuit design.
Clear operation feel and clear feedback
When pressed, the deformation of the shrapnel will produce a slight "click" sound and tactile feedback. Users can intuitively judge whether the switch is triggered, avoiding control failure caused by improper operation (especially in devices without screen feedback).
Low power consumption, suitable for small signal control
The rated current is usually ≤ 50mA (working voltage is mostly DC 12V/24V), only used for transmitting control signals, not directly driving high-power devices, low power consumption, suitable for battery powered portable devices (such as remote controllers, Bluetooth controllers).
Easy installation and maintenance
Simple structure (without complex mechanical components), can be quickly installed on circuit boards through surface mount or plug-in methods; If there is a malfunction (such as contact oxidation), the replacement cost is low, maintenance is convenient, and it is suitable for electronic devices produced in bulk.
Strong environmental adaptability
The shell is mostly made of high-temperature resistant plastic (such as PBT), which can withstand welding high temperatures (short-term 260 ℃); Some models come with waterproof sealing rings (IP65 rating), which can work stably in humid and dusty environments (such as kitchen appliances and outdoor instruments).
Haofu ElectronicsFocused on switch/socket/connector manufacturers
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