A Complete Guide to Reed Switches by Millennium Semiconductors

1. A Complete Guide to Reed Switches By Millennium Semiconductors India www.millenniumsemi.com

2. Introduction Electrical switches that are activated (turned on and off or changed over) by magnetism are known as Reed Switches. The most typical kind has two ferromagnetic metal wires or blades, known as reeds, that are thin, flexible, and slightly spaced apart inside a hermetically sealed glass bubble. These serve as the contacts for the reed switch. It should also be noted that the change-over type has three reeds instead of two. In the majority of other switch types, the electrical circuit is made or broken by physically manipulating a portion of the switch to open or close contacts. Typical examples of solid- state switches are pushbuttons, momentary switches, and rocker switches. www.millenniumsemi.com

3. How Do Reed Switches Work? A type of electrical switch that is activated by magnetism is the reed switch. Either a permanent magnet is inserted or an electromagnetic coil is passed current through to produce the actuation force. Reed relays depend on the latter setup. The reeds are two separate wire contacts that are contained in a hermetically sealed glass bubble or envelope. The switch contacts are these. To help prevent particle build-up from eventually impairing performance, this bubble is often filled with an inert gas like nitrogen. For increased durability, the glass envelope may also be enclosed with plastic, depending on the installation situation. The switch reeds are ferromagnetic, which means they're constructed of a metal with an iron foundation and may react to magnetic forces fast and easily. This is commonly a nickel and iron alloy, with 52% nickel in most cases. www.millenniumsemi.com

4. For a longer working life, they are frequently coated with an extra layer of harder metal. Only one of the wires is ferromagnetic for some varieties of reed switches, and the other will not move. Both reeds have a flattened and enlarged contact surface and are shaped like blades. Compared to single-point contacts, this provides more reliability. Iridium, rhodium, or ruthenium is sputtered onto the contacts in a microscopically thin layer as a coating over a tungsten, copper, or gold underlayer. Silver with low resistance and some reed switches that employ mercury are also alternatives. The inclusion of this extra layer ensures the best possible electrical contact. These switches must be positioned in precise orientations because the contacts are wet, which makes it difficult for liquid metal to leak and bridge the contacts when not in use. The contacts inside a reed switch's outer shell are pushed together or apart when a magnetic field is brought close enough to it. Depending on the direction of movement, this either completes or breaks the circuit. The two contact blades of a typically open reed switch, which is the most popular kind, are spaced apart by an air gap. www.millenniumsemi.com

5. Benefits of Reed Switches Reed switches provide further advantages as well, such as: No physical access to the switch is required to activate it. Less power consumption than the majority of other types of electronic switches Reliable, robust, small, and affordable (at least when designed for low-voltage applications, as the vast majority are) Highly sensitivity- and precision-customizable Long operational lifespan due to very low mechanical wear (typically in the millions, or even billions, of actuations) Simple to test the circuit without having to wire it up completely first Ability to function in a variety of hazardous environments. Reed switches are hermetically sealed, so they won't corrode and provide no risk of sparking when activated. www.millenniumsemi.com

6. Thank You An electrical switch operated by an applied magnetic field; the Reed Switches are effective sensing solutions. We provide Reed Switches at best price in India. info@millenniumsemi.com | www.millenniumsemi.com | +91 20 67177100