Also known as magnetic suspension, magnetic levitation (maglev) occurs when magnetic fields suspend an object in the air, with magnetic force overcoming gravitational force to keep it aloft. The idea of magnetic levitation has been around since at least 1904 when Robert Goddard, an American inventor and professor, authored a paper based on magnetic levitation as a concept. Maglev transferred from theory to reality in the 1910s when Emile Bachelet, a French-born engineer living in America, filed patents for maglev technology. A half-century later, during the late 1960s, Gordon Danby and James Powell of Brookhaven National Laboratory filed a patent for a maglev train utilizing superconducting magnets to enhance magnetic field power.
Whatever the application, there are two issues to consider for successful magnetic levitation. The first is the amount of upward force needed so that an object can defy gravity, and the other is the stability necessary to prevent neutralized lift through unexpected flipping or sliding. Maglev trains are among the most prominent uses of magnetic levitation, and they are capable of maintaining sufficient lifting force and stability for effective transportation.
How Do Maglev Trains Work?
A maglev train utilizes superconducting magnets set into each of a train car’s four corners, as well as a specialized track. A magnet becomes superconducting when its temperature reaches -450° F. This frigid temperature enables these magnets to produce magnetic fields with as much as 10 times the strength of the fields that regular electromagnets produce. It’s this capability that gives the maglev trains the ability to levitate and propel forward. The magnets located on a train car’s front two corners have their north poles facing out, with the back magnets positioned to have their south poles out.
As for the special track, or a guideway configured in a U-shape, it has metallic loops consisting of aluminum or other conductive metals dispersed along its concrete walls. These loops interact with the enhanced magnetic fields, generating an electric current that, in turn, creates an additional field.
There are three loop varieties that engineers place strategically along the guideways. One type produces a magnetic field that causes a train to levitate approximately 5 inches above the track. The second helps to stabilize train cars horizontally. In both cases, the loops use the force of magnetic repulsion to ensure that the train stays in its appropriate position on the track.
The last loop type is for propulsion, utilizing power from the alternating current as well as magnetic repulsion and attraction forces to move the train forward. When operators electrify the propulsion loops on the guideway, the resulting magnetic fields propel the train forward by pulling on the front magnets and pushing on the back. Magnets of matching poles repel when they face one another.
Benefits of Maglev Trains
Maglev trains offer an array of benefits to the transportation sector. These include:
- Increased speed. High-speed maglev trains can achieve and maintain speeds of 375 mph safely.
- Enhanced safety. These innovative trains rule out a number of the safety concerns inherent in traditional trains. For example, all maglev trains on the same track would have no risk of colliding because all the trains are moving at the same speed. Maglev trains also eliminate the chance of taking corners at sufficient speeds to derail, as magnetic forces only become stronger as the train moves from its standard positioning between the walls of its guideway and will effectively pull the train back.
- Smooth movement. Air is the only factor providing friction, so despite the speed, passengers won’t feel the usual turbulence associated with train travel. Also, as these trains have minimal contact with their tracks, this reduces overall vibration.
- Noise reduction. With minimized vibration comes the added benefit of reduced noise for passengers.
- Decreased downtime. Maglev trains experience fewer breakdowns due to mechanical issues than standard trains, which makes sense given the reductions in friction and vibration.
Custom Coils: A Magnetics Industry Leader
Magnetic levitation trains have the capability to successfully and safely maintain lift and achieve propulsion through the force of superconducting magnets and magnetic fields. Given their cost to build, maglev train use is not widespread, but magnetic levitation is an innovative concept that has the potential to revolutionize rail travel.
At Custom Coils, our team is committed to new ideas. We’ve been custom-designing and manufacturing magnetic components in the USA since 1967. For 55 years, we’ve continued to serve diverse industries ranging from transportation to communication and agriculture to aerospace with customer service that is second to none. Contact us today to experience the Custom Coils difference and learn more about our capabilities for innovative magnetic products.
Custom Coils Inc. designs and manufactures custom specialty coils for a variety of industries and applications. For even the most challenging projects, our experts can deliver high-quality design conceptualization, prototype development, testing, and production. This page will explain how electromagnetic coils work, their different types and applications, and important design considerations when creating custom solutions.
What are Electromagnetic Coils?
An electromagnetic coil, also known as an electric coil or inductor, is an electrical conductor containing a set of conductive wires wrapped around a specified shape and size. This can be a self-supporting (air core) design or include a specified core (ie. iron, ferrite) . Electrical coils are simple electronic components that provide inductance in an electromagnetic circuit.
There are many coil types to meet the needs of various equipment. Electromagnetic coils can vary by wire gauge, length, coil diameter, core material, and other factors. Since electromagnetic coils are powered by electricity, they can be turned on and off easily. Their magnetic strength can be altered by increasing or decreasing the electricity that flows around their core.
How Do Electromagnetic Coils Work?
Electromagnetic coils consist of conductive wire wrapped in a specific size and shape, producing a magnetic field. The magnetic field grows stronger when there are more turns of wire on the coil. Electromagnetic field strength is determined by the number of amp turns, the material selection of the core, and the strength of current. Removing electrical input disables the magnet.
When added to a wire coil, certain core materials can increase the strength of the magnetic field. Ferromagnetic materials—cobalt, nickel, iron, and steel—can amplify a denser magnetic field for the coil.
Types of Electromagnetic Coils
Since electromagnetic coils are critical components used in many industrial applications, the coils must meet the varied demands of each one. The following are some of the most common types of electromagnetic coils and how they’re used.
- Automotive electric coils: Ignition coils in automobiles typically consist of two sets of copper wires wrapped around an iron core. The primary winding is a heavy wire, while the secondary wire is smaller and lighter.
- Energy electric coils: These coils must be engineered to withstand harsh environmental conditions in remote locations.
- Electronic electric coils: Made from finely wound wire, coils for electronic devices are in high demand. Circuit board coils go into laminated transformers.
- Electric guitar electric coils: The single coil design is the most popular form of electric guitar coil, but another form is the double coil, which helps cancel out interference.
- Medical electric coils: Coils in medical equipment, such as Radiation Therapy Systems, must be reliable. These typically high power applications require very precise process and testing procedures.
- Military electric coils: Like medical coils, military coils must be accurate and reliable. They must also be able to perform in harsh conditions. These coils are commonly used in guidance systems, sensors, and navigation systems.
- Transportation electric coils: Railroad tracks, armatures, and signaling devices all use these coils, which can withstand the constant vibrations that occur in these environments.
- Wind-powered generator electric coils: These coils must withstand temperatures up to 200 °C. They are made from lightweight materials and insulated for added protection.
- Flowmeter electric coils: Used to measure the volume of liquid or gas going through a pipe, flowmeter coils must match the radius of the pipe.
- Traffic light sensor electric coils: Inductance meters attach to these coils and change when a car enters its field, alerting the traffic light of the car’s presence.
- Transformer electric coils: Transformers utilize multiple coils to conduct electricity, with primary windings on one side and secondary windings on the opposing side.
- Linear Accelerators coils: Electromagnets (Dipole magnets) are used extensively for beam guiding and bending to move charged particles where they need to go.
Electromagnetic Coil Applications
Electromagnetic coils vary in size, shape, and material depending on their application. While there are many industries that use electromagnetic coils, three industries in particular rely on coils for critical applications.
Electromagnetic components are vital to many types of medical equipment, including heart rate monitors, Radiation therapy systems, MRI systems and more. Diagnostic equipment—such as electrocardiogram (EKG) and electroencephalogram (ECG) machines—also require electromagnetic coils.
The military depends on electromagnetic coils for missile defense, protecting allied signals, and jamming enemy signals. Electromagnetic coils also apply to high-velocity electromagnetic rail guns.
Aerospace applications for transformers, inductors, and other electromagnetic parts must be highly precise and adhere to stringent guidelines. Electromagnetic aircraft launch systems, for example, must successfully launch aircraft from carriers.