Assemblies & Magnetic Devices




An electromagnet is a kind of magnet whose magnetic field is created by the flow of electric current. The magnetic field disappears when the current stops. Electromagnets offer the advantages of controlled holding power and on command release. Through the application of controlled DC electrical current, electromagnets have the ability to attract and hold ferrous materials with varying degrees of force, and to release the item as required.


Why Adams?

Adams supplies electromagnets in a variety of sizes, shapes and current strengths to meet your end-use requirements. Our technical sales team will work with you to determine what type of electromagnet will best suit your purpose.
Adams' electromagnets are available in flat-faced round and rectangle form or bi-polar rectangle. Click on the selected product type for a pop-up menu featuring product sizes and dimensions.
• Flat-Faced Electromagnets
• Bi-Polar Electromagnets


What to Know

There are several factors to evaluate when selecting the electromagnet to best suit your needs.
• Selecting the right electromagnet
• Effect of an Air Gap
• Power Sources
Electromagnets vs. Permanent Magnets


Applications

The strength, ability and versatility of electromagnets have rapidly evolved over the past few decades. Electromagnets are a significant element in several industrial processes, and have played a leading role in the development of the assembly line in modern factories. Electromagnets are used in many electric device applications, including:


• Electric bells

• Industrial lifting magnets

• Loudspeakers

• Magnetic locks

• Magnetic recording and data storage equipment

• Magnetic separation of materials

• Motors and generators

• Relays



Permanent Magnets vs Electromagnets

Permanent Magnets and Electromagnets: What are the Differences?
A permanent magnet is an object made from a material that is magnetized and creates its own persistent magnetic field.  As the name suggests, a permanent magnet is 'permanent'. This means that it always has a magnetic field and will display a magnetic behavior at all times.

An electromagnet is made from a coil of wire which acts as a magnet when an electric current passes through it. Often an electromagnet is wrapped around a core of ferromagnetic material like steel, which enhances the magnetic field produced by the coil.

Permanent Magnet v. Electromagnet: Magnetic Properties
A permanent magnet’s magnetic properties exist when the magnet is (magnetized). An electromagnetic magnet only displays magnetic properties when an electric current is applied to it. That is how you can differentiate between the two. The magnets that you have affixed to your refrigerator are permanent magnets, while electromagnets are the principle behind AC motors.

Permanent Magnet v. Electromagnet: Magnetic Strength
Permanent magnet strength depends upon the material used in its creation. The strength of an electromagnet can be adjusted by the amount of electric current allowed to flow into it. As a result, the same electromagnet can be adjusted for different strength levels.

Permanent Magnet v. Electromagnet: Loss of Magnetic Properties
If a permanent magnet loses its magnetic properties, as it does by heating to a (maximum) temperature, it will be rendered useless and its magnetic properties can be only recovered by re-magnetizing. Contrarily, an electromagnet loses its magnetic power every time an electric current is removed and becomes magnetic once again when the electric field is introduced.

Permanent Magnet v. Electromagnet: Advantages
The main advantage of a permanent magnet over an electromagnet is that a permanent magnet does not require a continuous supply of electrical energy to maintain its magnetic field. However, an electromagnet’s magnetic field can be rapidly manipulated over a wide range by controlling the amount of electric current supplied to the electromagnet.

Note:  This is a high level overview of permanent magnets as they compare to electromagnets.  There are more details available relating to the differences stated.  Please contact us with your specific questions and we’ll be happy to share all the fine points.