The Most Common Applications Of Neodymium Magnets
Neodymium magnets are the strongest magnets commercially available and due to their strength, even tiny neodymium magnets are effective, making them incredibly versatile. Since the creation of the first neodymium magnet, they have been used for many purposes.
Industries such as electrical motor manufacture, medical science, renewable energy, and technology all rely on super-strength neodymium magnets. Without neodymium magnets, many advancements over the last 30 years would not have been possible.
Because of their super-strength, incredible performance, and resistance to demagnetisation alongside the fact that neodymium magnets come in all shapes and sizes, their uses are endless.
Common Uses of Neodymium Magnets:
Hard Disk Drives
A hard disk drive records data by magnetising and demagnetising a thin film of ferromagnetic material on a disk. Each disk is separated into many tracks and sectors and each sector has many tiny individual magnetic cells which are magnetised by thdrivees read/write head when data is written to the drive.
Hard drive heads are made from ceramic wrapped in a fine wire coil. When writing, the coil is energised, a strong magnetic field fors, and the recording surface adjacent to the gap is magnetised.
Strong magnets are also used in the actuator that moves the read/write head into position.
Audio Equipment such as microphones, acoustic pick-ups, headphones and loudspeakers
Permanent magnets are used in speakers alongside a current-carrying coil which converts electricity into mechanical energy that moves the speaker cone that in turn changes the pressure of the surrounding air creating sound.
Microphones work in reverse; a diaphragm is attached to a coil of wire which sits within a permanent magnet, when sound moves the diaphragm, the coil moves too. As the coil moves through the magnetic field created by the permanent magnet an electrical signal is produced which is characteristic of the original sound.
A reed switch is a switch operated by a magnetic field. Reed switches consist of contacts placed on ferrous reeds, encased in a sealed glass tube. They can be designed to be open or closed by default in the absence of a magnetic field and are activated by bringing a neodymium magnet close to the switch.
A typical use for reed switches is detecting the opening and closing of doors in burglary alarm systems.
Most processing facilities will use some form of magnetic separation system to remove contaminating ferrous and paramagnetic items from production or processing lines. This is usually done using a form of conveyor system and strong filter rod magnets.
Permanent magnets are essential in the heavy engineering and manufacturing industries, used for lifting large ferrous items. Switchable release magnets using super-strong neodymium magnets are commonly used as they are supplied with a quick-release switching mechanism.
ABS (anti-lock braking) System Sensors
Passive ABS sensors use neodymium magnets wrapped inside copper coils. A sensor is placed close to the ABS reluctor ring and as the ring rotates a voltage is induced in the copper wire. This signal is monitored by the vehicle’s computer system and used to define wheel speed.
Point of Sale Displays
Every time you enter a shop or restaurant you might not realise that you are surrounded by neodymium magnets but they will be there. That’s because many point of sale display advertising signs and stands use small are held together using small but strong neodymium magnets or are suspended from steel ceilings using neodymium hook magnets.
MRI scanners produce a large magnetic field that aligns the protons in a human body in the direction of the magnetic field. Radiofrequency waves are then directed at the body producing detailed internal images. Many ‘open’ MRI machines used in hospitals use large neodymium magnets, they literally help save lives.
Motors & Generators
Electric motors rely upon a combination of an electromagnet and a permanent magnet, usually a neodymium magnet to convert electric energy into mechanical energy. A generator is reverse, it converts mechanical energy into electric energy by moving a conductor through a magnetic field.
Magnetically Coupled Pumps
Magnetically coupled pumps consist of a motor-driven shaft with an attached ring of powerful magnets and another smaller ring of magnets attached to another shaft connected to the impeller that sits within the larger ring of magnets.
As the motor turns the drive shaft and one set of magnets, the magnetic field generated turns the other set of magnets which powers the impeller. With this type of motor, there is no mechanical contact between the motor and the impeller.
Magnetically coupled pumps or magnetic impeller pumps provide two main advantages over non-magnetic pumps, due to the impeller is connected to the driving magnets and shaft by magnetism alone, if the impeller is obstructed and stops turning the motor can continue to turn without burning out avoiding any lasting detriment to the motor.
The second is relevant to applications in which liquid could potentially seep into the motor unit (for example, a pond motor) as with a magnetically coupled motor you can completely separate the motor unit from the impeller, which is usually within a hermetically sealed case.