Touch Springs Using springs to build capacitive sensors Electro-capacitive sensing is a robust alternative to traditional mechanical switches. However, there are applications where the printed circuit board cannot be placed directly under the overlay, nor can the printed circuit board be attached to the device enclosure. Such applications include household appliances such as stoves, washing machines, refrigerators, microwave ovens, and various vehicle electronics such as radios, TV tuners, control panels, and in-seat occupant detection systems. Different shapes of springs can be used in practical applications. Each shape has its pros and cons. Common springs include circular springs, variable diameter circular springs, and rectangular springs.

Touch spring refers to the special spring button specially used for capacitive and single-chip touch screen electrical appliances. Touch springs are also called touch sensing springs, button springs, and contact springs. A robust capacitive sensing alternative to traditional mechanical switches. With retractable touch keys, the product can be controlled by touch keys without changing the shell mold, and the touch sensitivity is very good. Metal Spring Inductors - Can be used as an alternative to solid state conductance sensors so that the PCB can be positioned away from the overlay and provide a reliable sensor connection under operating conditions with high vibration or extreme temperature changes. In addition, springs can provide other features such as backlighting, blending mechanical and capacitive buttons, and more.

Compression springs are helical springs that bear axial tension, and extension springs are generally made of circular section materials. When not under load, the coils of the tension spring are generally tight and there is no gap between the coils. A number of different termination devices or "hooks" are used to secure the source of tension for the extension spring. An extension spring works the opposite of a compression spring. Compression springs act in the opposite direction when they are compressed, and tension springs act in the opposite direction when they are extended or pulled apart. When the ends of the extension spring are pulled apart, the spring tries to pull them back together. Like compression springs, extension springs also absorb and store energy. But unlike compression springs, most extension springs are usually under some degree of tension, even without any load. This initial tension determines how tightly the tension spring coils without any load.

Compression springs are coil springs that are subjected to axial pressure. The cross-section of the materials used is mostly circular, and they are also rolled with rectangular and multi-strand steel. The springs are generally of equal pitch. The shapes of the compression springs are: cylindrical, conical There is a certain gap between the rings of the compression spring, and the spring shrinks and deforms when it is subjected to an external load, storing the deformation energy. Compression springs provide resistance to external load pressure. Compression springs are generally wire coiled at equal pitches and have a fixed wire diameter. Compression springs use multiple open coils to provide resistance to external load pressure. That is, they push back against external pressure. Compression springs are generally wire coiled at equal pitches and have a fixed wire diameter. In addition, there are also conical compression springs, or a combination of conical and linear springs. Depending on the field of application, compression springs can be used to resist pressure and store energy. Round wire is the most commonly used compression spring, but there are also compression springs made from square, rectangular, and specially shaped wires.

One sample selection   　　 When preparing samples, care should be taken to eliminate some abnormal factors that affect fatigue strength. There are two types of factors that affect the spring fatigue strength test: one is internal factors, such as chemical composition, metallographic structure, etc.; the other is external factors, such as surface condition, shape and size, temperature, surrounding medium, etc. Generally, it is based on the inherent fatigue strength of the material (internal factors), and the external factors are considered for correction. Therefore, in the test process, the test piece should try to eliminate the influence of external factors. When conducting the first type of test, samples can be prepared according to the conditions of use, or samples can be taken directly from the product. The second and third types of tests should be sampled according to specific requirements.   　　A. Specimen size The spring size is always different, so even under the same amount of deformation, the stress and fatigue strength between them are not exactly the same. In order to accurately reflect the fatigue strength of the sample, the measurement accuracy of the size should be improved on the basis of reducing the size error.   　　 1) The measurement accuracy of the sample size should be greater than 0.5%. When the material size is less than 2 mm, its accuracy should be 0.01 mm. If 0.5% of the sample size is less than 0.01mm, the accuracy is 0.01mm.   　　2) When measuring the size of a circular cross-section (such as outer diameter D2, spring wire diameter d), two diameters perpendicular to each other on the same cross-section should be measured, and the average value should be used as the diameter.   　　3) According to the spring shear stress calculation formula:   　　 It can be seen that in order to reflect the maximum shear stress, the maximum value of spring D/D should be measured.   　　B. Sample shape   　　1) In order to ensure that the spring does not produce eccentric load after being stressed, the parallelism of the two ends of the spring and the perpendicularity of the whole spring should be strictly checked.

1. As a compression spring or tension spring There is no difference in function between left-handed spring and right-handed spring when used as tension and compression springs, but the right-handed spring is the main application. 2. As a torsion spring 1. Left-handed spring: The torsion force of the left-handed spring acts on the left-handed rotation, so it can only be used where the left-handed force is needed during application. 2. Right-handed spring: The torsion force of the right-handed spring is to rotate to the right, and the applicable range can only be the position that needs to be rotated to the right. Three, spiral spring The left-handed spring and the right-handed spring are just accumulators. They have the function of storing energy, but they cannot release the energy slowly. To realize the function of releasing slowly, it should be realized by the "spring + large transmission ratio mechanism". Classification of coil springs: 1. According to the different characteristics of the load during work, the spiral spring can be divided into three types: compression, tension and torsion; 2. According to the structural characteristics, it can be divided into two categories: cylindrical spiral spring and variable diameter spiral spring; variable diameter spiral spring mainly bears compression load; 3. According to its shape characteristics, it can be divided into cone, scroll, concave and convex. 4. In production and use, coil springs can also be divided into two types according to the forming method and material diameter: large coil springs and small coil springs; the former is usually hot-formed, and the latter is cold-formed. 5. In other categories, there are many types of spiral springs, which can be divided into: ordinary cylindrical spiral springs; variable diameter spiral springs. According to the direction of the helix, it can be divided into: left-handed spring; right-handed spring. 6. Variable diameter spiral springs are divided into: conical spiral springs, scroll spiral springs, and concave spiral springs. 7. Cylindrical spiral spring, simple structure, convenient manufacturing, and the most widely used. Its characte