Welcome to this installment of EE Classroom on Inductors

Electrical circuits just can’t do their thing without them. Used alone as a low-pass filter, with capacitors and resistors to create filters, or to store electromagnetic energy in the magnetic and electric field, inductors enjoy applications in multiple areas from consumer electronics to automotive to healthcare. Within these and many other sectors, this simple coil of wire wound around a central core plays a major role in the critical power management functions. Design engineers have choices — lots of them — so carefully weighing quality, price, support, and a design “best-fit” is time well spent.

In this classroom, we’ve curated resources to help you make the most of that time. Are you choosing inductors for energy efficient power applications or other filtering? We’ve got some basics for that. What’s are the causes and solutions to differential and common-mode noise? We’ve asked and answered that for you, too. And has it been a while since you touched base with Maxwell’s equations? Skip the dense math and read about what the equations really mean. Finally, four additional resources guide you through inductor specifications, application frequencies, voltage ranges and ratings.

No need to take notes — we’ve got you covered.

Aimee Kalnoskas

Senior Editor, EE World Online


Training Center Classroom

Inductors Classroom Sponsored by

RF  •  Power  

Stray current and parasitic capacitance in circuits at RF

Strange things can happen at high frequencies. It begins with stray current in your printed circuit board (PCB)

Choosing inductors or ferrite beads for power supply filtering

Simply adding some inductance to clean up a switching regulator seems like a good idea but it isn't that straightforward.

Choosing inductors for energy efficient power applications

Energy efficiency in power supplies can be as much about the inductors as about the circuit topology.

When inductors self resonate

Inductors only behave like inductors below because of what's called their self resonant frequency.

Related Resources

An Introduction to Inductor Specifications

Inductors as RF Chokes

Forward or Flyback?
Which is Better? Both!

Operating Voltage Ranges for Inductors

Magnetics  •  Noise  

Maxwell’s equations: An intuitive view for engineers

Electrical engineers tend to dislike hearing about Maxwell’s equations. It bring up some frustrating memories to everyone.

Power supply designers take a hard look at soft magnetics

The fundamental parameters that describe magnetic materials and their energy storage capacity.

Two noise sources which are not as obvious to many engineers as noise that results from the switching action of the power supply.

What is differential mode noise?

The Basics

Basic Electronics – Magnetism, Electromagnetism and Inductance

To understand inductance, it is important first to understand magnetism and electromagnetism.

Basic Electronics: How to select an inductor

Key considerations when selecting from solenoidal coils, toroids, or pot cores inductors.

Basic Electronics – Reading inductor packages

Inductor packages have specific numerical and color-coding systems to indicate nominal value and tolerance.

Coilcraft produces inductors for a long list of customers in telecommunications, computers, instrumentation and consumer electronics. Most are standard, off-the-shelf products, but many are still custom designed to meet customers' specific requirements. 

Coilcraft's worldwide headquarters are in Cary, Illinois, 30 miles northwest of Chicago's O'Hare Airport. In addition to corporate offices, this facility houses our engineering department plus manufacturing. European headquarters are located in Cumbernauld, Scotland, near Glasgow. There are another nine plants in the U.S. and Mexico as well as production centers in Scotland, Taiwan, Singapore, China and Malaysia. This diversity of locations offers several advantages to our customers.