KY-021 Reed Switch Module

Reed switches are abbreviated as dry reed contacts and are passive electronic switching elements. They possess advantages such as a simple structure, small size, and ease of control. The switch is housed within a sealed glass tube containing two iron elastic reed plates and is filled with a rhodium metal inert gas. During normal operation, the glass tube keeps the two reeds separated using special materials. However, when a magnetic substance approaches the glass tube and interacts with the magnetic field lines, the two reeds inside the tube become magnetized and attract each other, making contact and completing the circuit. When the external magnetic force disappears, the flexibility of the reeds causes them to separate, breaking the circuit.

As a device that utilizes magnetic field signals for controlling line switching, reed switches can serve as sensors for counting numbers, measuring spacing, etc. (mainly used in security systems for monitoring entrances and windows). Additionally, they find widespread use in various communication devices. In practical applications, these switches are often controlled by a permanent magnet to toggle the two metal sheets, earning them the nickname "magnetic switches."

• Model Name: KY-021
• Voltage: 3.3V to 5V
• Color: Black
• Dimension: 2.4cm x 1.5cm x 0.5cm

• 1 x KY-021 Reed Switch Module