Electromagnets

Electromagnets are a type of magnet where the magnetic field is produced by an electric current, which is totally different from permanent magnets. Typically, they consist of a wire wound into a coil around a magnetic core, usually made of iron or another ferromagnetic material. Electromagnets are temporary magnets and artificial magnets, meaning they are only magnetic when electric current flows through the coil. The strength of the magnetic field can be adjusted by changing the amount of electric current, offering precise control for various needs.

Electromagnets are widely used because their magnetic field can be turned on and off, and their strength can be varied. They are versatile in applications ranging from industrial machines to everyday electronic devices when magnetic forces are only needed for short periods, such as electric motors, generators, transformers, solenoids, magnetic lifting systems, and magnetic separation equipment. This adaptability makes them essential in modern technology.

Types of Electromagnets

Electromagnets can be classified according to various criteria. However, as permanent magnet manufacturers, our expertise and business scope for electromagnets are currently limited to flat-faced electromagnets. These artificial magnets feature a flat surface and an island pole electromagnetic circuit design, making them ideal for holding flat, smooth ferromagnetic objects.

Within this specific category, we classify flat-faced electromagnets solely based on their shape: round and rectangular. This classification aligns closely with our traditional business of pot magnets, due to their similar structures and applications. Round and rectangular flat-faced electromagnets are commonly used in manually operated or automated systems for temporarily picking and placing ferromagnetic parts. Additionally, these temporary magnets are available in a variety of sizes and pull forces. Moreover, we can modify existing products or create entirely bespoke solutions according to your needs and specifications.

Rectangular Electromagnets

Round Electromagnets

History of Electromagnets

The history of electromagnets dates back to 1820, when Danish scientist Hans Christian Ørsted made the groundbreaking discovery that electric currents produce magnetic fields. In the same year, French scientist André-Marie Ampère showed how iron could be magnetized by inserting it into an energized solenoid. A few years later, in 1824, British scientist William Sturgeon invented the first electromagnet.

His early design featured a horseshoe-shaped iron piece wrapped with about 18 turns of bare copper wire—the only kind available, as insulated wire had not yet been invented. The iron was varnished to insulate it from the windings. When current passed through the coil, the iron magnetized and attracted other iron objects, but the magnetism vanished once the current stopped. Weighing just seven ounces (roughly 200 grams), Sturgeon’s electromagnet could lift nine pounds (about 4 kilograms) using power from a single-cell battery. However, the uninsulated wire restricted the design to a single, spaced-out layer of windings, limiting its overall strength.

Significant advancements came in 1830 from American scientist Joseph Henry, who adopted silk-insulated wire, drawing inspiration from Schweigger’s galvanometer with its multiple turns. This allowed Henry to layer thousands of wire turns around the cores, greatly boosting their power. One of his creations could support 2,063 pounds (936 kilograms), paving the way for electromagnets’ broad adoption, especially in telegraph sounders.