Electromagnets are devices that use electricity to generate a magnetic field. Their unique design gives them various advantages over traditional magnets and makes them well-suited for certain applications.
The following article serves as a guide to industrial electromagnets. It highlights how they work, types available, key advantages, and typical uses. Additionally, it covers the design and manufacturing solutions available from Milhous Company, a premier designer and manufacturer of magnetic systems.
Everything You Need to Know About Electromagnets
How Do They Work?
At their most basic, electromagnets consist of a coil of insulated conductive wire (typically made from copper) wrapped around a metal (typically iron or steel) core. When current is applied to the coil, it creates a temporary magnetic field. When the current is stopped, the magnetic field disappears.
The size, shape, and material of the coil and core vary depending on the desired use of the electromagnet. Generally speaking, as the size of the core and coil increase, they can conduct greater amounts of current, which, in turn, generates a stronger magnetic field. Following this principle, large electromagnets can create extremely strong magnetic fields. Users can also control the strength of the magnetic field by increasing and decreasing the amount of current channeled through the coil.
Types of Electromagnets
There are three main types of electromagnets, each of which has unique design characteristics that make it useful for particular applications. They are:
- Resistive. Resistant electromagnets are typically manufactured with copper wires. The wires conduct current, producing a weak magnetic field. Wrapping the wire around a piece of metal (e.g., an iron rod) concentrates the magnetic field; the more windings, the stronger the field.
- Superconductive. Superconducting electromagnets use a copper plate instead of a coil. The plate is cooled to an extremely low temperature using liquid nitrogen or helium, which stops the copper atoms from interfering with the electrons in the current. As a result, the plate has significantly reduced electrical resistance, which means the electromagnet can continue to run even when the current is stopped.
- Hybrid. Hybrid electromagnets use a combination of resistive and superconducting electromagnetic technology. The exact design varies from one solution to another. One example of a hybrid electromagnet found at the University of Florida is over 20 feet in height and 35 tons in weight. It uses deionized water to maintain low temperatures and reduce electrical resistance.
Electromagnets offer numerous advantages over traditional magnetics, such as:
- Higher strength. The strength of a permanent magnet is limited by the type of material used in its construction. In contrast, electromagnets can be engineered to produce magnetic fields that are up to 20 times stronger than the strongest permanent magnet.
- Better control. The strength of an electromagnet can be controlled by increasing or decreasing the current, allowing for a level of control that is difficult to achieve, if not impossible, for other types of magnets. This control extends to turning the magnet off altogether, which you can accomplish by simply flipping a switch to stop the electrical current.
- Greater consistency. The magnetic fields in permanent magnets decay with use and time. As such, they must be recharged to maintain the same level of magnetic power. In comparison, electromagnets will maintain the same magnetic field given a continuous and constant current supply.
Uses of Electromagnets
Electromagnets are highly versatile and controllable, which makes them ideal for a variety of applications, including:
- Industrial machinery. Electromagnets are often used to sort metal scrap and lift heavy objects in industrial applications. They are also incorporated into electric actuators to convert electrical current into motion.
- Filtration. Magnet filtration systems can use either permanent magnets or electromagnets to remove iron particles from fluid streams. The advantage of using the latter is that they enable operators to control when the magnetic field that attracts and captures the particles is active. Milhous Company’s BallMatrix® electromagnetic filtration systems remove 99% of magnetically susceptible particles from fluids, regardless of fluid viscosity, flow rate, and particle size.
- Medical and scientific equipment. Scientific and medical devices that use electromagnets include magnetic resonance imaging (MRI) machines, nuclear magnetic resonance (NMR) spectrometers, and particle accelerators.
- Power transformers. Electromagnets use electromagnetic induction to control the current frequency and voltage through transformers along power line installations.
- Security and access control systems. Since electromagnets can be turned off and on, they are used for strong locks and access control equipment. A powerful electromagnetic lock will hold the door closed until the correct access method is used, at which point the current is removed, disengaging the lock.
- Trains. Maglev trains use electromagnets to keep the train elevated over the track. They are also used to help the trains accelerate at high speed.
Custom Electromagnet Design & Manufacturing Solutions
Milhous Company has a worldwide reputation as a leading designer and manufacturer of cutting-edge magnetic systems. Our product offerings include electric motor windings, resistive and superconducting electromagnets, and electromagnetic coils for the high-energy physics, medical, power generation, and energy markets.
We serve as a one-stop shop for electromagnet needs. From initial concept development to production, we provide a range of design and analysis services to ensure customers receive components and systems that fully meet their specifications and standards. Our services include thermal and magnetic field modeling, material analysis, and mechanical and electrical design. We also use advanced software for product design verification.
Our manufacturing facility houses a complete CNC machining center, which we use to fabricate mandrels, molds, and component parts required for customer projects. It also has winding and assembly equipment that utilizes the best technologies available in the industry today. Our test lab is equipped with 3D scanning systems and advanced magnetic and electrical test instruments, enabling us to fully comply with the most stringent testing requirements.
- Magnetic field modeling
- Mechanical design
- Electrical design
- Thermal modeling
- Material analysis
- Conductor design
- CAD drawing
- SolidWorks 3D modeling
- Coil winding and magnet assembly for resistive and superconducting systems
- Design assistance
- Design verification
- Reverse engineering
- Resistive and superconducting electromagnets
- Electric motor windings
- Electromagnetic coils
Quality Control Equipment
- HDI 3D scanning
- Coordinate measurement machine (CMM)
- Baker motor analyzers
- National Electric Code
- ISO 9001:2015
- Quality Management System
- Medical Device Quality Management System
Contact Milhous Company Today For More Information!
To learn more about our electromagnet solutions and how they can benefit you, contact us today. To get started on your solution, request a quote.