{"id":1192,"date":"2017-06-13T08:00:19","date_gmt":"2017-06-13T15:00:19","guid":{"rendered":"http:\/\/www.autodesk.com\/products\/eagle\/blog\/?p=1192"},"modified":"2023-09-25T14:12:55","modified_gmt":"2023-09-25T21:12:55","slug":"inductor-plain-english","status":"publish","type":"post","link":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/inductor-plain-english\/","title":{"rendered":"What is an Inductor, In Plain English"},"content":{"rendered":"

The Reluctance of Inductance – What is an Inductor, In Plain English<\/h1>\n\n\n

Can you name the trio of passive components for electronic devices? We\u2019re talking about <\/span>resistors<\/span><\/a> (R), <\/span>capacitors<\/span><\/a> (C), and inductors (L). This trio forms the foundation for all of our electronic devices, providing a pathway towards making some amazing things with such simple concepts. So while resistors are over there resisting the flow of electricity, and capacitors are trying their best to hold a charge, what in the world are inductors doing? This component is a little more mysterious than the others, using the magic of magnetism. Want to know what kind of secrets are inside? Let\u2019s find out!<\/span><\/p>\n\n\n

Like Apples to Apples, Kind Of<\/h2>\n\n\n

Before we even dive into the details of an inductor, let\u2019s first start off with something we are familiar. Just like a <\/span>capacitor<\/span><\/a>, an inductor also has the job of storing electrical energy. Except instead of storing energy in an electric field as a capacitor does, an inductor stores energy in a magnetic field.<\/span><\/p>\n\n\n\n

\"inductor_magnetic_field\"\/
All of the energy in an inductor gets stored in a magnetic field. (Image source<\/a>)<\/em><\/figcaption><\/figure>\n\n\n\n

When you look at the trio of passive components, capacitors and inductors are kind of like twin brothers. They both do similar activities, storing energy, they just have their own unique personality and way of getting that job done. Where the capacitor likes to maintain a constant voltage, an inductor prefers to maintain a constant current. They\u2019re both achieving the same end goal of storing and impeding the flow of energy, just in their own way.<\/span><\/p>\n\n\n\n

Unlike the complexity of a capacitor\u2019s physical structure, inductors are a bit simpler, consisting of a simple coil of wire around a magnet, or even air. But why the coil shape? If there\u2019s anything to know about electromagnetism, it\u2019s that sending an electric current down a piece of copper produces a magnetic field.<\/span><\/p>\n\n\n\n

Inductors take advantage of this natural property by amplifying the size of the magnetic field with a coiled wire. When a current is sent through the copper wire of an inductor, you get a magnetic field that is much larger, and much stronger than what you\u2019d get in a straight path of copper.<\/span><\/p>\n\n\n\n

\"many-different-inductors\"\/
Inductors come in all shapes and sizes, each with their own core and copper. (Image source<\/a>)<\/em><\/figcaption><\/figure>\n\n\n\n

This is the real beauty of an inductor. By creating a magnetic field, you can convert electrical energy into magnetic energy, and store it there until it\u2019s needed! <\/span><\/p>\n\n\n

Yet Another Water Analogy to Understand<\/h2>\n\n\n

Now that you know what an inductor is, how exactly does it work in a circuit? Inductors work based on a property called inductance, which is simply the ability to store some quantity of energy in a magnetic field.<\/span><\/p>\n\n\n\n

Let\u2019s think about a simple example like a water wheel to understand what’s going on here. Let\u2019s say you have a dammed river with a water wheel in the river\u2019s channel, ready to generate some electricity. Now let\u2019s say you open that barrier, and send water pouring through towards the water wheel. When it hits the wheel, initially the water is going to slow down as the water wheel works to match the speed of the water. This right here is the process of an inductor \u201ccharging\u201d up as a current is sent through it.<\/span><\/p>\n\n\n\n

\"inductor-waterwheel\"\/
A waterwheel all ready to be \u201ccharged\u201d up, just like our inductor! (Image source<\/a>)<\/em><\/figcaption><\/figure>\n\n\n\n

And then imagine that you decide to dam the river up again. That water wheel is going to slow down at a smooth, steady pace until it comes to rest again. And just like an inductor, the process of collapsing a magnetic field when there\u2019s no current flowing happens steadily over time, not all at once.<\/span><\/p>\n\n\n\n

Sounds simple enough, right? But what\u2019s the benefit of storing and releasing an electrical charge? Here are some examples:<\/span><\/p>\n\n\n

Smoothing Current<\/h3>\n\n\n

When you need a very smooth current for something like a DC power supply, then the magnetic field in an inductor helps to stabilize the current as it journeys along a circuit. And if you have a decreasing current in a circuit that needs to remain steady, you can use the reserves in an inductor\u2019s magnetic field to pump the current back up to its original levels.<\/span><\/p>\n\n\n\n

\"inductor-smoothing-current\"\/<\/figure>\n\n\n

Acting as a Sensor<\/h3>\n\n\n

You\u2019ll also find inductors being used in traffic stoplights. By placing an inductor underneath the road with a sensor, and then driving a large metal object over it, like your car, you\u2019ve added a core to your inductor, creating a bigger magnetic field! The sensor in the stoplight can then use this data to know that there\u2019s a car waiting, and so the light changes.<\/span><\/p>\n\n\n\n

\"induction-loop-traffic-sensors\"\/<\/figure>\n\n\n

Transmitting Current<\/h3>\n\n\n

When you get into the larger family of inductors, you\u2019ll also find them being used in power transmission systems. Here they\u2019re responsible for stabilizing massive amounts of current and making sure that the current remains stable during transit.<\/span><\/p>\n\n\n\n

\"wireless-power-transmission-coils\"\/<\/figure>\n\n\n\n

There are a ton of other uses for inductors in electronic devices, some of which depend on the certain inductance rating, such as:<\/span><\/p>\n\n\n\n