Reed Switches

Reed switches, also known as reed switch sensors or reed sensor switches, are a specialised type of electrical switch that is actuated by a magnetic field. The most common design features two thin, flexible, ferromagnetic metal wires or blades, referred to as the reeds, positioned slightly apart in a hermetically sealed glass capsule. These reeds serve as the reed switch contacts. It's worth noting that the change-over type, a variation within the reed sensor family, employs three reeds instead of the standard two, offering more complex switching capabilities

Read our guide to reed switches to learn more.

Types of Reed Switches

There are various types of reed switches, including normally open, normally closed, and changeover or SPDT reed switches, providing diverse solutions for various magnetic sensing needs

Form A: Normally-Open Reed Switches

Normally-open reed switches, a common type of reed sensor, remain open until a magnetic field is applied. Upon exposure to a magnetic field, the reed contact sensor closes, completing the circuit. This functionality is ideal for applications requiring a switch to activate only when a magnetic field is present, such as in security systems or proximity sensors.

Form B: Normally-Closed Reed Switches

Conversely, normally-closed reed switches maintain a closed circuit until a magnetic field is introduced. When subjected to a magnetic field, the reed sensor switch opens, interrupting the circuit. This configuration is useful in applications where a circuit needs to be deactivated upon magnetic field detection, like safety interlocks or alarm systems.

Form C: Changeover or SPDT Reed Switches

Changeover or SPDT reed switches, also known as reed contact switches, provide both normally open and normally closed contacts within a single unit. These switches facilitate the switching between two distinct circuits. When a magnetic field is applied, one circuit opens while the other closes, offering versatile control in applications requiring circuit alternation or signal routing.

Advantages of Magnetic Reed Sensors

Magnetic reed switches, including micro reed switch and heavy duty magnetic reed switch variants, offer several distinct advantages, making them a reliable choice for a wide range of applications:

• Hermetically sealed contacts: These contacts provide robust protection against dust, moisture, and other environmental factors, ensuring consistent reliability even in harsh operating conditions.
• Low power consumption: Reed switches require minimal energy for operation, rendering them ideal for battery-powered devices and energy-efficient systems.
• High switching speeds: Their rapid response times make them well-suited for applications demanding quick and precise actuation, contributing to efficient system performance.

Selection Criteria for Reed Sensor Switches

When selecting a reed sensor switch, several critical factors warrant careful consideration:

• Electrical specifications: Evaluate the maximum switching voltage, current, and power ratings to ensure compatibility with your circuit and prevent damage from exceeding these limits.
• Sensitivity (Ampere-Turns): This parameter dictates the magnetic field strength needed for actuation, affecting the switch's responsiveness to magnetic fields in your application.
• Mounting and packaging: Choose between surface-mount or through-hole options based on your application's design. Surface-mount is ideal for compact designs, while through-hole is preferred for robust connections.

Avoid Common Mistakes When Purchasing Reed Switches

When purchasing reed switches, it's crucial to avoid several common pitfalls to ensure optimal performance and longevity.

• Choosing the wrong wattage rating: Selecting a switch with an inadequate wattage rating can lead to premature failure or damage to the circuit, due to the switch being unable to handle the power load.
• Insufficient switching life: Opting for a reed switch with a switching life too short for your system's operational demands can result in frequent replacements and increased maintenance costs.

Industrial Applications of Reed Switches

Security Systems

In security systems, reed switches act as reliable intrusion detectors. Normally-closed reed switches are often used in door and window sensors, triggering alarms when a magnetic field is disrupted, indicating unauthorised entry.

Automotive Industry

Within the automotive sector, reed switches play a crucial role in position sensing and fluid level monitoring. Magnetic reed switch sensors are commonly found in fuel level sensors and door interlocks, ensuring accurate and dependable performance.

Medical Devices

Medical devices utilise reed switches for their compact size and reliability. Micro reed switches, in particular, are employed in pacemakers and other implantable devices, providing precise switching functions while maintaining biocompatibility.

Industrial Automation

Industrial automation systems rely on heavy duty magnetic reed switches for position sensing and limit switching. Their robust design withstands harsh environments, ensuring accurate and consistent performance in automated machinery.

Telecommunications

In telecommunications, reed switches find applications in signal routing and switching circuits. For example, reed contact sensors are used for their high switching speeds and low contact resistance, contributing to efficient signal transmission.

Household Appliances

Reed sensors are employed in various household appliances, such as washing machines and refrigerators, for level sensing and door interlocks. Their durability and reliability ensure consistent operation in everyday use.

Your Trusted Reed Switches Supplier and Manufacturer

RS Australia stands as a trusted supplier, distributor, and manufacturer of high-quality reed switches, including magnetic reed switches and reed sensor switches. We source our products from reputable brands like KEMET, Assemtech, and Littelfuse, ensuring superior quality.

Beyond reed switches, RS Australia provides a comprehensive range of electrical products, such as DC power connectors and copper wiring, offering a convenient one-stop shop for your project needs. Browse our user-friendly website and order today to benefit from swift and flexible deliveries, meeting all your project requirements efficiently.

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