Reed Sensor is a switch sensor based on the principle of magnetic sensitivity. It is composed of a metal reed sealed in a glass tube. When an external magnetic field acts on it, the reed closes or opens, thereby achieving the on-off control of the circuit. The following are its main features and applications:
1. Working principle
The reed sensor has two magnetic reeds inside, which are encapsulated in a glass tube filled with inert gas (such as nitrogen) or vacuum.
When there is no magnetic field: The reed remains open (normally open type) or closed (normally closed type).
When there is a magnetic field: The magnetic force causes the reed to attract or separate, changing the state of the circuit.
2. Main features
Low power consumption: No external power supply is required; it is triggered solely by changes in the magnetic field.
Fast response: The switch action is completed at the microsecond level.
High reliability: No mechanical wear and long service life.
Anti-corrosion: Glass encapsulation protects the internal metal sheet.
Multiple packaging forms: such as through-hole, surface mount, etc., to adapt to different applications.
3. Typical applications
Liquid level detection: Such as magnetic flap level gauges, which trigger reed switches through float magnets to achieve remote monitoring of the liquid level.
Smart door lock: Detects the door opening and closing status, the position of the door handle and the double locking status.
Industrial limit switches: Used for position detection of robotic arms, elevators, etc.
Home appliance control: such as washing machine door opening and closing, refrigerator door sensing.
Counting and safety systems: such as bicycle speedometers, door and window alarms.
4. Advantages and Disadvantages
Advantages: Small size, long service life, and strong anti-interference ability.
Disadvantages: Not suitable for high current/high voltage scenarios, and prone to mechanical shock damage.
5. Relevant product examples
MK6 Series: PCB-mounted reed sensor, suitable for home appliances and industrial control.
Littelfuse Reed sensor: Used for status monitoring of smart door locks.
Swiss REED level gauge: Combined with magnetic float ball to achieve remote liquid level transmission.
Post time: Aug-01-2025