Summary
Highlights
An inductor is an electrical component that stores energy in its magnetic field and can release it rapidly. This ability to store and release energy quickly makes them vital in many circuits.
Using a water pipe system with a heavy water wheel, the video illustrates how an inductor resists initial current flow, then allows full flow, and finally continues to push current even after the power source is removed. This demonstrates the inductor's opposition to changes in current.
Similar to the water wheel, when connected in parallel with a lamp, an inductor initially resists current, diverting it through the lamp. As the magnetic field builds, the inductor's resistance drops, and current flows through it, turning off the lamp. When power is cut, the inductor releases stored energy, momentarily relighting the lamp.
Current flowing through a wire creates a magnetic field. Coiling the wire intensifies this field, allowing the inductor to store energy. When the power is removed, this stored magnetic energy converts back into electrical energy, pushing electrons and resisting the change in current.
Inductors resist changes in current. When current increases, they create an opposing back electromotive force (EMF) to slow the increase. When current decreases, they actively push electrons to maintain the current, demonstrating their inertidal properties.
Comparing a resistor and an inductor on an oscilloscope shows that a resistor exhibits an instant current rise and fall, while an inductor shows a gradual, curved increase and decrease in current, illustrating its opposition to instantaneous changes.
Inductors are typically coiled wires, sometimes with shielding. They are represented by specific symbols in circuit diagrams. Many common devices like motors, transformers, and relays contain coiled wires and thus act as inductors.
Inductors are used in boost converters, AC chokes, frequency filters, and in transformers, motors, and relays. Inductance is measured in Henrys (H); a higher value means more energy storage and a longer time for magnetic field changes. Inductance is best measured accurately with an RLC meter.