How Magnetic Reed Switch Sensors Work with Neodymium Magnets

What is a magnetic reed switch sensor?

Magnetic reed switch sensor is a line switching device controlled by magnetic field signal, also known as magnetic control switch. It is a switching device induced by magnets. The commonly used magnets include sintered Neodymium magnet, rubber magnet and ferrite permanent magnet. The reed switch is a passive electronic switching element with contacts. The shell is usually a sealed glass tube filled with inert gas and equipped with two iron elastic reed electric plates.

A magnetic switch is similar to an electromagnet. When the coil is energized, it produces magnetism, attracts the armature to move, and turns on the switch. When the power is off, the magnetism disappears and the switch is disconnected. It is mainly induced by a permanent magnet. It is more convenient and belongs to a sensor.

How does the magnetic reed sensor work?

The reed in magnetic switch, also known as magnetron, is a switching element controlled by magnetic field signal. When the magnetic switch is not in the working state, the two reeds in the glass tube are not in contact. Using a permanent magnet usually Neodymium magnet, under the action of the magnetic field generated by the permanent magnets, the two reeds are of opposite polarity, and sufficient suction is generated between the two reeds to contact each other, so as to connect the circuit. When the magnetic field disappears, without the influence of external magnetic force, the two reeds will separate and disconnect the circuit because of their own elasticity.

Advantages of magnetic switch sensor

1. Using the magnetic reed switch, the magnetic reed sensor can sense that all kinds of movement with permanent magnets.

2. Reed switches draw zero current when they are on, which makes them an ideal choice in energy-saving equipment applications.

3. Even when air, plastic and metal are separated, permanent magnets can be applied.

4. Magnets and reed switches are generally separated by physical enclosures or other obstacles.

5. Magnetic reed switch sensor is used to detect movement, count, detect liquid level height, liquid level measurement, switch, implant equipment in harsh environment, etc.

Forms of activating reed switches

The most common way to excite a reed switch is to use a NdFeB magnet. There are four typical incentive forms:

Figure 1 shows that the movement of the block hard magnet from front to back is the state change of the reed switch.

Figure 2 shows the state change of a reed when the Neodymium rectangular magnet rotates.

Figure 3 shows the opening and closing point by passing the reed switch through the center of the Neodymium ring magnet.

Figure 4 shows interference of the permanent magnet rotating around the shaft on the opening and closing of the reed switch.