What is an Electromagnet?

An electromagnet is an electrical component that generates the magnetic field. What it can do is pretty much the same as a regular magnet; the electromagnet attracts and repels magnetic objects. That being said, there are a couple of differences between the electromagnet and a permanent magnet. What’s more, based on how the electromagnet works, there are several types of it. In the following sections, we are going to go over the basic idea of how it works and what it can do for us. Let’s read on.

How Does the Electromagnet Work? 

The main components of the electromagnet are a wire and a magnetic core. Yes, it is this simple. The wire is a conductor (usually copper wire), and the magnetic core is usually an iron rod. The copper wire winds into a coil that wraps the iron core while the two wire ends connect to a power supply. When the power is on and the current runs through the close loop of the wire, the moving charges within the wire create the magnetic field and turn the coil into a magnet. The magnetism disappears when the power is off.

Are Magnets and Electromagnets Different?

This is a question that is commonly asked. To put it simply, magnets and electromagnets are the same with respect to what they can do. They both attract/repel objects that share dissimilar/similar charges respectively. However, when it comes down to how they create magnetic forces, they are different. While magnets feature the north and south pole that align with Earth’s magnetic field, the electromagnet creates the pole according to the direction the current runs through it. The magnetism of magnets is permanent but that of electromagnets isn’t. This is the key difference.

Characteristics

Electromagnets come with some unique characteristics. For one thing, its magnetic force is not permanent. We can turn it on and off. For the other, the magnetic force is adjustable. The three factors that control the magnetic force are the turns of the coil, the material of the core, and the size of the current. Generally speaking, the magnetic force becomes greater as the number of turns in the coil increases. Also, when the electric current increases, the strength of the electromagnet increases.

As for the core material, there are actually a number of materials, such as steel, ferrites, silicon alloying, and permalloy, to just name a few. Regardless of the material, metals, or compounds, the core serves to concentrate the magnetic flux and strengthen the magnetic force. When choosing the core material, relative permeability is the key factor. Permeability in electromagnetism refers to a material’s ability to form a magnetic field, and iron is deemed to be the best core material. The fact that we get to control the magnetic field allows for more possibilities of application.

Applications

Electromagnets apply the physical phenomenon of magnetic induction to work. Induction can create a magnetic field out of electricity and create electricity out of a magnetic field too. We can use electromagnets to generate utility power, create the mechanical force to move objects, and hold objects in place. Below lists some most important applications of electromagnets today. Let’s take a look.

• Generator

A generator is a machine that uses electromagnetic induction to create utility power. Within the generator, there is a unit that provides mechanical energy. The energy source is typically internal combustion engines, but it can be gas turbines, water turbines, or wind turbines too. With the energy source, the generator turns the mechanical energy into utility power by means of electromagnetism.

• Motor

The electric motor is like a generator except it works in the opposite way. It converts electricity to mechanical energy with electromagnets. The main components of a motor are the rotor and the stator. The stator carries magnets (or electromagnets) and surrounds the rotor. The rotor also has a set of electromagnets to interact with the stator when the magnetic field is applied. When the stator exerts the magnetic force onto the rotor, the latter spins and hence creates the mechanical energy to move a load.

• Work-holding System

The use of electromagnets can be rather straightforward. In the field of manufacturing, it acts as a type of work-holding system to hold workpieces in place or to move them. For example, in machining processes, such as grinding, milling, or turning, the magnetic chuck or electromagnetic chuck generates a strong attraction force onto the metal workpiece to clamp it. In the construction industry, the electromagnetic lifter is effective in lifting and moving metallic building materials and debris. Operators also use the lifter to extract metals from other materials.

• Solenoid

By definition, solenoids are a type of motor that produces linear motions instead of rotary motions. How a solenoid work is similar to an electric motor. When the electricity is applied to the solenoid, it creates a magnetic field around a core called the armature. The movement of the armature is then used to move a load. For example, the solenoid can act as a valve to close and release fluids. Such a mechanism is also effective in opening and closing a circuit. Summit Elec-tech is a professional solenoid manufacturer. We stock a full collection of solenoid products, including solenoid valves and solenoid coils. Contact us right now for more product info.

• Transformer

Power transformers and inductors are the essential components in most (if not all) electric and electronic products that apply electromagnetism. The primary goal of the transformer is to isolate the electric/electronic device from the power source and regulate the power before it enters the circuit of the device. It filters out interferences and downscale/upscales the voltage so that the device can work without underperforming or even damaging.

• Permanent Electromagne

Permanent electromagnets, or electro-permanent magnets (EPM), is peculiar compared with other types of electromagnets. While most electromagnets are triggered or activated in response to a force or energy, the EPM dulls with the presence of power. The EPM has a permanent magnetic field. But when the current runs through the EPM, opposing magnetizations are produced and its magnetic field is neutralized resultingly. As some of you might already tell, EPMs are used when an application requires temporary magnetic force. On the other hand, when an application needs magnetism most of the time and magnetism loss occasionally, the EPM is better. One of the EPM applications is the locking system for household access control.

Pros and Cons

Using electromagnets is advantageous for it provides the freedom to control and adjust the magnetic force. Using just enough force to handle work is energy-effective and cost-saving. By controlling the output magnetic force, we can also mitigate the risk of damaging other onsite equipment. The other advantage is the large power-to-size ratio. The electromagnet is smaller than the permanent magnet that provides the same magnetic force. Plus, it is much easier to handle and install since we can turn off the magnetic force when necessary.

The major (and probably the only) disadvantage is the heat. To continuously generate the magnetic force, the electromagnet needs a continuous supply of electricity and over time the wire coil heats up easily. As the heat accumulates, the electricity-to-magnetism conversion becomes less efficient. To maintain the performance of the unit over a long period of time, heat management is definitely a challenge, especially for the heavy-duty units used in industrial settings.

Final Words 

The electromagnet does bring about convenience and effectiveness when it comes to material handling, power conversion, and motion control applications. There are more applications to the electromagnet that we did not include here. we hope you find this post helpful and walk away with more understanding about electromagnets. Again, if you need more information with regard to our product and service, leave us a message here and we will get back to you timely.