Electromagnet in IoT: Working, Applications & Benefits in Smart Devices (2025 Guide)

Introduction to Electromagnets

An electromagnet is a type of magnet in which the magnetic field is produced by the flow of electric current. Unlike permanent magnets, electromagnets are temporary—they can be turned on and off using electricity. This controllable magnetic field makes them ideal for use in modern electronics, automation, communication systems, and more.

Electromagnets are fundamental components in various fields such as robotics, sensors, motors, relays, solenoids, and industrial machinery.

How Does an Electromagnet Work?

The working principle of an electromagnet is based on Ampere’s Circuital Law and Faraday's Law of Electromagnetic Induction. When electric current passes through a conductor (typically a copper wire), it generates a magnetic field around it. By winding the wire into a coil around a ferromagnetic material (like iron), the magnetic field is intensified.

• Current ON ➝ Magnetic field created

• Current OFF ➝ Magnetic field disappears

Components of an Electromagnet

1. Conductor Coil (Usually copper wire)

2. Power Source (Battery or DC supply)

3. Ferromagnetic Core (Iron or steel rod)

4. Switch or Control Circuit

Types of Electromagnets

1. Temporary Electromagnet

   • Basic structure
   • Used in simple experiments and educational kits
   • Field disappears immediately after power cut

2. Permanent Electromagnet

   • Modified with special core materials
   • Holds some magnetic property even after power is off
   • Used in magnetic locks and switches

3. Superconducting Electromagnet

   • Made from superconducting coils
   • Offers very high magnetic fields
   • Used in MRI machines and particle accelerators

4. Relay-Type Electromagnet

   • Used to switch circuits on/off
   • Found in automation systems and vehicles

5. Industrial Electromagnet

   • Heavy-duty usage
   • Seen in cranes, scrap yards, and magnetic separators

Advantages of Electromagnets

• Controlled Magnetism – Switch ON/OFF at will

• High Efficiency – Stronger than permanent magnets

• Customizable Strength – Based on current and coil turns

• Safe to Use – No residual magnetism

• Compact & Durable – Ideal for embedded systems

Applications of Electromagnets

• Magnetic Relays & Switches

• Electric Motors & Generators

• Loudspeakers & Microphones

• Magnetic Locks in Security Systems

• MRI Scanners in Healthcare

• Scrap Yard Cranes (lifting metal)

• Particle Accelerators & Scientific Instruments

Real-World Example: Electromagnet in Magnetic Door Lock

A magnetic door lock uses a coil wrapped around a metal core. When the current passes, it creates a strong magnetic field that holds the door closed by attracting a metal plate. When the power is turned off, the magnetic force disappears and the door unlocks.

How It Works:

• User activates a switch or RFID
• Current flows in the coil
• Magnetic field is created instantly
• Lock engages (door remains shut)
• When system is turned off, door releases

Key Technical Specifications (Sample)