Frame-type electromagnets, also known as box-type electromagnets, are so named due to their rectangular shape. These frame electromagnets are devices that generate electromagnetic fields. When the transformer core rotates externally and its output power matches the resistance of the conductive winding, the coil with current exhibits magnetic properties similar to those of a magnet. We typically shape them into strips or horseshoes to facilitate easier magnetization of the transformer core. Additionally, to ensure that the electromagnet is quickly demagnetized when power is disconnected, we often use soft iron or silicon steel materials with rapid demagnetization properties. Once powered, these electromagnets become magnetic. When the power is turned off, the magnetic field dissipates. Square electromagnets have numerous applications in our daily lives, as their use has significantly enhanced the output power of generator sets.
Let's first take a look at the composition and principle of electromagnets: Electromagnets are primarily composed of coils, an iron core, and an armature. The iron core and armature are generally made of soft magnetic materials. They are typically categorized into DC electromagnets and communication electromagnets. What is the principle behind communication electromagnets?
When the coil of the communication electromagnet is inserted, the core and armature are magnetized, becoming two magnets with opposite poles. As the adhesive force exceeds the reactive force of the tension spring, the armature's turning point moves towards the core. When the current in the coil falls below a certain value or the power supply is interrupted, the electromagnetic attractive force is less than the reactive force of the tension spring, and the armature will return to its original release direction under the action of the reactive force.
It's worth noting that the electromagnetic absorption force of the communication electromagnet is composed of the magnetic field of the magnetic separator and the magnetic field of two alternating electric fields generated by the magnetic separator, plus the force of direct current net weight. This makes it easier to release, resulting in a lower output power, a larger transformer core volume, and higher coil energy consumption. The low power factor leads to a larger coil current and severe heat generation, which not only wastes electrical energy but also prematurely ages and damages the coil. It's quite a problem. Therefore, most of the time, we opt for direct current over communication electromagnets.
