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What is the Magnetic Reed Switch?

The magnetic reed switch, also known as a dry reed pipe, is an electric switch operated by a magnetic field.

In 1936, Walter Ellwood of Bell Telephone Laboratories invented the sensor magnetic reed switch and applied for a US patent on June 27, 1940, with the patent number 2264746. The basic type seals two magnetic reed pieces in a glass tube. Although the two pieces overlap, there is a small gap in the middle. When an external magnetic field is applied, the two magnetic reed pieces contact and then conduct. Once the magnet is pulled away from the switch, the magnetic reed switch returns to its original position.

Advantages of magnetic reed switch

  • The contacts are sealed together with an inert gas in a glass tube and are not affected by external atmospheres.

  • The response speed of the action is fast.

  • The action system and circuit are located on the same axis, suitable for high-frequency transmission applications.

  • Small size and light weight.

  • The contacts have superior corrosion resistance and wear resistance, long service life, and stable switching action can be obtained.

  • Combined with a permanent magnet, it can easily and economically form a non-contact switch.

Structure of magnetic reed switch

The magnetic cylinder reed switch is composed of two magnetic reed pieces (usually consisting of iron and nickel) sealed in a glass tube. The two magnetic reed pieces overlap but with a small gap in the middle, and an external suitable magnetic field will cause the two magnetic reed pieces to come into contact.

The contacts on these two spring pieces are coated with a layer of very hard metal, usually rhodium and ruthenium, which greatly enhances the life of the switching times. Nitrogen or some equivalent inert gas is usually injected into the glass tube, and some magnetic reed switches have their interiors vacuumed to improve their switching voltage performance.

Performance of magnetic reed switch

Magnetic Reed switch is a unique technology, and its fully-sealed nature allows it to be used in almost all environments. Although the structure of the switch of the sensor for cylinder is simple, it involves many processes during its production and processing. Over the years, the size of the magnetic reed switch has evolved from about 50 millimeters to as small as 6 millimeters, making it applicable to more fields, especially for radio frequency and fast time domain applications. Magnetic Reed switches have been widely used in fields such as home appliances, automotive, communications, industry, healthcare, and security.

Since 2001, ALIF has been dedicated to the application and innovation of magnetic switches. Its products are widely used in hundreds of fields such as mechanical processing and industrial automation, and exported to more than 40 countries and regions worldwide, providing reliable products and customized solutions for its partners. It adheres to the belief that innovation can make magnetic sensor and its application better.



ALIF is a professional cylinder sensor factory, they are well known to customers for their comprehensive products, good quality, and reasonable prices.

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