{"id":17624,"date":"2024-05-07T23:17:56","date_gmt":"2024-05-08T06:17:56","guid":{"rendered":"http:\/\/www.autodesk.com\/products\/eagle\/blog\/?p=470"},"modified":"2026-01-07T15:16:40","modified_gmt":"2026-01-07T23:16:40","slug":"3-rules-humble-circuit-place-world-electronics","status":"publish","type":"post","link":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/3-rules-humble-circuit-place-world-electronics\/","title":{"rendered":"The 3 Rules of How A Circuit Works (2024 Update)"},"content":{"rendered":"\n<p><em>Learn the basic rules of how a circuit works including voltage flow, loads, and conductive materials.<\/em><\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"683\" src=\"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-content\/uploads\/2021\/06\/Manufacturing-Treau-5892-1024x683.jpg\" alt=\"How a circuit works: Autodesk Fusion\" class=\"wp-image-22182\" srcset=\"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-content\/uploads\/2021\/06\/Manufacturing-Treau-5892-1024x683.jpg 1024w, https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-content\/uploads\/2021\/06\/Manufacturing-Treau-5892-300x200.jpg 300w, https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-content\/uploads\/2021\/06\/Manufacturing-Treau-5892-768x512.jpg 768w, https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-content\/uploads\/2021\/06\/Manufacturing-Treau-5892-1536x1024.jpg 1536w, https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-content\/uploads\/2021\/06\/Manufacturing-Treau-5892.jpg 1920w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p><span style=\"font-weight: 400;\">Greetings new engineers. This is a wonderful place to begin, with the simple circuit, which forms the building block to every piece of electronics in our world. Once fully understood, you\u2019ll be ready to begin your own journey in designing and troubleshooting them yourself.<\/span><\/p>\n\n\n\n<?php\nfunction autodesk_fusion_cta_horizontal() {\n    ob_start();\n    ?>\n    <style>\n        .cta-section-horizontal {\n            background: #ddd; \/* Much lighter grey background *\/\n            padding: 12px; \/* Adjusted padding *\/\n            border-radius: 8px;\n            box-shadow: 0 3px 5px rgba(0, 0, 0, 0.2);\n            color: #333; \/* Darker text color for better readability *\/\n            display: flex;\n            align-items: center;\n            justify-content: space-between;\n            max-width: 650px; \/* Width adjusted for a more compact look *\/\n            margin: 20px auto;\n            position: relative;\n            flex-wrap: nowrap; \/* Prevent wrapping *\/\n        }\n\n        .cta-section-horizontal img {\n            width: 60px; \/* Slightly larger logo *\/\n            height: auto; \/* Maintain aspect ratio *\/\n            margin-right: 12px; \/* Adjusted spacing *\/\n            background-color: #ddd; \/* Match the background color *\/\n            padding: 6px; \/* Adjusted padding *\/\n            border-radius: 8px; \/* Slightly rounding to match container *\/\n            box-shadow: 0 0 0 4px #ddd; \/* Blend with background *\/\n        }\n\n        .cta-text {\n            flex: 1;\n            margin-right: 12px; \/* Adjusted spacing *\/\n        }\n\n        .cta-title {\n            font-size: 18px; \/* Slightly larger title font size *\/\n            font-weight: bold; \/* Bold title *\/\n            color: #f9a825; \/* Orange color *\/\n            margin-bottom: 4px; \/* Reduced margin *\/\n        }\n\n        .cta-info {\n            display: none; \/* Hide description *\/\n        }\n\n        .cta-buttons {\n            display: flex;\n            gap: 8px; \/* Adjusted button spacing *\/\n            align-items: center;\n        }\n\n        .cta-button {\n            padding: 8px 12px; \/* Button padding *\/\n            font-size: 12px; \/* Smaller font size for buttons *\/\n            font-weight: bold;\n            text-transform: uppercase;\n            border-radius: 4px; \/* Slightly rounded corners *\/\n            border: 2px solid transparent;\n            cursor: pointer;\n            transition: all 0.3s ease;\n            display: inline-flex; \/* Use inline-flex to ensure proper alignment *\/\n            align-items: center; \/* Center align text vertically *\/\n            justify-content: center; \/* Center align text horizontally *\/\n            text-decoration: none !important; \/* Ensure no underlines with !important *\/\n            color: inherit; \/* Use the button's text color *\/\n        }\n\n        .cta-button.white-button {\n            background-color: #fff;\n            color: #333;\n            border: 2px solid #ddd;\n        }\n\n        .cta-button.white-button:hover {\n            background-color: #333;\n            color: #fff;\n            border: 2px solid #f9a825;\n        }\n\n        .cta-button.black-button {\n            background-color: #f9a825;\n            color: #fff;\n            border: 2px solid #f9a825;\n        }\n\n        .cta-button.black-button:hover {\n            background-color: #fff;\n            color: #f9a825;\n            border: 2px solid #fff;\n        }\n    <\/style>\n\n    <div class=\"cta-section-horizontal\">\n        <img decoding=\"async\" src=\"https:\/\/autodesk.com\/products\/fusion-360\/blog\/wp-content\/uploads\/2024\/09\/autodesk-fusion-product-icon-400.png\" alt=\"Autodesk Fusion Logo\">\n        <div class=\"cta-text\">\n            <h1 class=\"cta-title\">Elevate your design and manufacturing processes with Autodesk Fusion<\/h1>\n        <\/div>\n        <div class=\"cta-buttons\">\n            <a href=\"https:\/\/www.autodesk.com\/products\/fusion-360\/trial-intake-flow\" class=\"cta-button white-button\">Get a 30-Day Free Trial<\/a>\n            <a href=\"https:\/\/www.autodesk.com\/products\/fusion-360\/extensions\" class=\"cta-button black-button\">See Plans and Pricing<\/a>\n        <\/div>\n    <\/div>\n\n    <?php\n    return ob_get_clean();\n}\nadd_shortcode('autodesk_fusion_cta_horizontal', 'autodesk_fusion_cta_horizontal');\n?>\n\n\n<h2 class=\"wp-block-heading\" id=\"the-building-blocks-of-the-circuit\">The Building Blocks of the Circuit<\/h2>\n\n\n<p><span style=\"font-weight: 400;\">Before diving into a complete circuit, it\u2019s wise to first wrap your mind around the individual pieces that make up the whole, being flow, load, and conductivity. These are considered the basic laws that govern how circuits operate.<\/span> <span style=\"font-weight: 400;\">We\u2019ve organized these principles into three basic rules:<\/span><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Rule 1<\/strong> &#8211; <span style=\"font-weight: 400;\">Electricity will always want to flow from a higher voltage to a lower voltage.<\/span><\/li>\n\n\n\n<li><strong>Rule 2<\/strong> &#8211; <span style=\"font-weight: 400;\">Electricity always has work that needs to be done.<\/span><\/li>\n\n\n\n<li><strong>Rule 3<\/strong> &#8211; Electricity always needs a path to travel.<\/li>\n<\/ul>\n\n\n<h3 class=\"wp-block-heading\" id=\"rule-1-its-all-about-the-flow\"><strong>Rule 1 &#8211; It\u2019s All About the Flow<\/strong><\/h3>\n\n\n<p><span style=\"font-weight: 400;\">Every electronic circuit needs a power source, whether that\u2019s from an AA battery that you can pop into your Xbox One controller or something with a bit more force like your wall outlet that can power a large number of devices. The electricity that comes flowing out from these sources is measured in voltage, or volts, or simply V.<\/span> The movement of electric current in a circuit is driven by the supply voltage provided by the power source.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter is-resized size-full wp-image-471\"><img decoding=\"async\" src=\"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-content\/uploads\/eagle\/2017\/02\/danger-high-voltage.jpg\" alt=\"danger-high-voltage\" class=\"wp-image-471\" style=\"width:711px;height:auto\"\/><figcaption class=\"wp-element-caption\"><em>Yeah, we\u2019re talking about that kind of voltage! When it\u2019s high enough it can do some serious damage.<\/em><\/figcaption><\/figure>\n\n\n\n<p><span style=\"font-weight: 400;\">Regardless of where this power flows from, its purpose is always the same &#8211; to get from one area to another, and in the process to do some work, like charging your computer or turning on your lights.<\/span><\/p>\n\n\n\n<p><span style=\"font-weight: 400;\">The fundamental component of this flow of power is also Rule 1: electricity will always want to flow from a higher voltage to a lower voltage. Always. This is called <\/span>potential<span style=\"font-weight: 400;\">. You could say that it\u2019s the potential electricity has to move from one area to another. <\/span><\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full wp-image-472\"><img decoding=\"async\" src=\"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-content\/uploads\/eagle\/2017\/02\/High-to-low.png\" alt=\"potential-energy\" class=\"wp-image-472\"\/><figcaption class=\"wp-element-caption\"><em>Flow of High (Positive) Voltage to Low (Negative) Voltage.<\/em><\/figcaption><\/figure>\n\n\n<h2 class=\"wp-block-heading\" id=\"realword-example\">Real-word example<\/h2>\n\n\n<p><span style=\"font-weight: 400;\">How does this relate to our real world? Let\u2019s take the simple battery as an example:<\/span><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><span style=\"font-weight: 400;\">A battery has two sides (also called the negative terminal<\/span>)<span style=\"font-weight: 400;\">, the negative side is the low voltage, measuring in at 0v, and the positive side is the high voltage, measuring in at 1.5v. <\/span><\/li>\n\n\n\n<li><span style=\"font-weight: 400;\">Energy will always want to flow out of the positive side of the battery to get to the negative side to find balance. <\/span><\/li>\n\n\n\n<li><span style=\"font-weight: 400;\">To do this, it needs to flow along something, usually a copper wire, and do some work in the process, like turn on a light or spin a motor.<\/span><\/li>\n<\/ul>\n\n\n\n<p><span style=\"font-weight: 400;\">At the end of the day, all electricity wants to find its equilibrium at ground (0v). The only way to do this in a battery is to move from the positive to the negative side. We&nbsp;benefit from this natural desire of energy by placing some objects in the way that it needs to flow through, allowing us to turn on lights, power motors, and switch transistors on and off in a computer. <\/span><\/p>\n\n\n<h3 class=\"wp-block-heading\" id=\"rule-2-getting-some-work-done\"><strong>Rule 2 &#8211; Getting some work done<\/strong><\/h3>\n\n\n<p><span style=\"font-weight: 400;\">Now, you might have some electricity that wants to flow from a higher voltage to a lower voltage, but what\u2019s the point? The only reason to make electricity flow is to give it some work to do. This process of electricity doing work in a circuit is called <\/span><b>load<\/b><span style=\"font-weight: 400;\">. Without having a load, or some work for electricity to do, then there is no point in having a circuit. A load can be anything you can imagine, such as:<\/span><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Spinning<\/strong><span style=\"font-weight: 400;\"> a motor that turns the propellers of a drone.<\/span><\/li>\n\n\n\n<li><strong>Turning<span style=\"font-weight: 400;\"> <\/span><\/strong><span style=\"font-weight: 400;\">on a LED on a charging cable to indicate that your laptop is plugged in.<\/span><\/li>\n\n\n\n<li><strong>Connecting<\/strong><b> <\/b><span style=\"font-weight: 400;\">your headset wirelessly with your laptop to listen to music.<\/span><\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full wp-image-473\"><img decoding=\"async\" src=\"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-content\/uploads\/eagle\/2017\/02\/led-rgb-lights-640x0.jpg\" alt=\"christmas-leds\" class=\"wp-image-473\"\/><figcaption class=\"wp-element-caption\"><em>Tis\u2019 the season, electric load comes in many forms, one of which is powering these LEDs. (<a href=\"http:\/\/www.digitaltrends.com\/mobile\/light-bulb-li-fi-wireless-internet\/\">Image source<\/a>)<\/em><\/figcaption><\/figure>\n\n\n\n<p><span style=\"font-weight: 400;\">Notice that all of these loads are actions. Electricity always makes something physical happen, even if we can\u2019t see it with our own eyes. But why is it called a load? You can think of it as a burden to whatever is powering your circuit. Spinning a motor requires electricity, and this takes energy away from the power supply that it once had.<\/span> The power dissipated by a load depends on the resistance values of the components in the circuit, which determines how much energy is converted to work or heat.<\/p>\n\n\n\n<p><span style=\"font-weight: 400;\">Remember Rule 2 &#8211; <\/span><b>Electricity always has work that will need to be done<\/b><span style=\"font-weight: 400;\">. Without work, then a circuit has no use. <\/span><\/p>\n\n\n<h3 class=\"wp-block-heading\" id=\"rule-3-following-a-path\"><strong>Rule 3 &#8211; Following a path<\/strong><\/h3>\n\n\n<p><span style=\"font-weight: 400;\">The third and final rule is what makes the first two rules possible &#8211; electricity needs a path to travel. This path acts as a kind of middleman. Let\u2019s say you plug your laptop charger into a wall socket, and then into your laptop. It charges, obviously, but without that cord between your computer and wall outlet, nothing would happen.<\/span><\/p>\n\n\n\n<p><span style=\"font-weight: 400;\">This is because electricity needs a path to follow to get from one destination to another. And the journey is always the same:<\/span><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Power &#8211;<\/strong><b> <span style=\"font-weight: 400;\">Electricity always starts from a source, like a battery or an outlet.<\/span><\/b><\/li>\n\n\n\n<li><strong>Journey<\/strong> &#8211; <span style=\"font-weight: 400;\">It then takes its journey along a path, doing its work along the way.<\/span><\/li>\n\n\n\n<li><strong>Destination<\/strong> &#8211; <span style=\"font-weight: 400;\">It then arrives at its final destination, finding rest at the lowest voltage point.<\/span><\/li>\n<\/ul>\n\n\n\n<p>This path that electricity walks on is made up of what\u2019s called conductive material, which is made up of common metals like copper, silver, gold, or aluminum. Electricity loves to travel on this stuff. Electricity is also very selective, and it won\u2019t bother traveling on paths made up of inductive materials. This includes things like rubber, glass, and even air.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-full wp-image-474\"><img decoding=\"async\" src=\"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-content\/uploads\/eagle\/2017\/02\/copper-wire.jpg\" alt=\"copper-wire\" class=\"wp-image-474\"\/><figcaption class=\"wp-element-caption\">See all of those copper wires? Electricity loves traveling on this conductive material.<\/figcaption><\/figure>\n\n\n\n<p><span style=\"font-weight: 400;\">Remember Rule 3 &#8211; <\/span>Electricity always needs a path to travel on<span style=\"font-weight: 400;\">. Without a path, it can&#8217;t go anywhere. <\/span><\/p>\n\n\n<h2 class=\"wp-block-heading\" id=\"understanding-ohms-law\">Understanding Ohm\u2019s law<\/h2>\n\n\n<p>If you want to truly master electric circuits, there\u2019s one rule you can\u2019t ignore: Ohm\u2019s Law. This fundamental principle is the backbone of circuit analysis, helping you understand how voltage, current, and resistance interact in any circuit configuration\u2014whether you\u2019re working with simple series circuits, parallel circuits, or more complex series-parallel combination circuits.<\/p>\n\n\n\n<p><strong>Ohm\u2019s Law<\/strong> states that the current flowing through a conductor between two points is directly proportional to the voltage across those points and inversely proportional to the resistance between them. In other words, if you know any two of these values\u2014voltage (V), current (I), or resistance (R)\u2014you can always find the third using the classic Ohm\u2019s Law equation:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><strong>V = I \u00d7 R<\/strong><\/code><\/pre>\n\n\n<h2 class=\"wp-block-heading\" id=\"putting-it-all-together-the-complete-circuit\">Putting it all together: The complete circuit<\/h2>\n\n\n<p><span style=\"font-weight: 400;\">Let\u2019s put all of these rules together now in a complete definition of a circuit.<\/span><\/p>\n\n\n\n<p><strong>A circuit is simply a path that electricity can flow through.<\/strong><\/p>\n\n\n\n<p><span style=\"font-weight: 400;\">And with that simple concept, people have built some complex circuits that have sent humans to space and the depths of our deepest oceans. For now, we\u2019ll keep things simple and put together our first circuit. Here\u2019s what you\u2019ll need if you want to follow along:<\/span><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><span style=\"font-weight: 400;\">(1) 9-volt battery<\/span><\/li>\n\n\n\n<li><span style=\"font-weight: 400;\">(1) 470 \u03a9 resistor<\/span><\/li>\n\n\n\n<li><span style=\"font-weight: 400;\">(1) Generic LED<\/span><\/li>\n\n\n\n<li><span style=\"font-weight: 400;\">(3) Test leads with alligator clips<\/span><\/li>\n<\/ul>\n\n\n\n<p>In more advanced setups, you might use three resistors or other circuit elements to explore how the whole circuit behaves.<\/p>\n\n\n<h3 class=\"wp-block-heading\" id=\"step-1-adding-a-power-source\">Step 1 &#8211; Adding a Power Source<\/h3>\n\n\n<p><span style=\"font-weight: 400;\">Going back to our Rule of Three, the first says that electricity will always want to flow from a higher voltage to a lower voltage. Okay, so this means we need a power source in this circuit, we\u2019ll add our 9v battery. <\/span>Batteries are common voltage sources in circuits, and the total voltage supplied by the battery determines how much energy is available to the circuit.<\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter wp-image-491 size-medium\"><img decoding=\"async\" src=\"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-content\/uploads\/eagle\/2017\/02\/bat-227x300.jpg\" alt=\"9v-battery\" class=\"wp-image-491\"\/><figcaption class=\"wp-element-caption\"><em>The beginning of our circuit starts with a 9v battery.<\/em><\/figcaption><\/figure>\n\n\n\n<p><span style=\"font-weight: 400;\">Rule 1 is now fulfilled. We have a power source that has a high voltage on the positive end (+) and 0v on the negative end (-). But all of that electricity is going to waste if we don\u2019t do something with it, so let\u2019s give it some work (load).<\/span><\/p>\n\n\n<h3 class=\"wp-block-heading\" id=\"step-2-adding-some-work\">Step 2 &#8211; Adding some work<\/h3>\n\n\n<p><span style=\"font-weight: 400;\">We now want our electricity to do some work for us before it can come to rest, so let\u2019s have it turn on a simple <a href=\"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/diode-led-work\/\">LED light<\/a>. You\u2019ve likely seen these everywhere, in your Christmas tree, flashlights, light bulbs, etc\u2026 So we\u2019ll take this LED and place it on the other side of our battery.<\/span><\/p>\n\n\n\n<p><span style=\"font-weight: 400;\">Now, the one thing to mention about an<\/span> LED is that they are sensitive and can\u2019t have too much power running through them, so we need to add a resistor. We won\u2019t go into the details now<span style=\"font-weight: 400;\"> but just know that a resistor will do like its name says &#8211; resist the flow of electricity enough for our LED to handle it. Let\u2019s place that resistor to the left of our LED.<\/span><\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-medium wp-image-492\"><img decoding=\"async\" src=\"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-content\/uploads\/eagle\/2017\/02\/led-bat-res-300x287.jpg\" alt=\"led-battery-resistor\" class=\"wp-image-492\"\/><figcaption class=\"wp-element-caption\"><em>Adding some work to our circuit with a LED and resistor.<\/em><\/figcaption><\/figure>\n\n\n\n<p><span style=\"font-weight: 400;\">Great, Rule 2 is now complete, and our electricity has some work to do. But it doesn\u2019t have a way to complete its work without a path, let\u2019s add that now.<\/span><\/p>\n\n\n<h3 class=\"wp-block-heading\" id=\"step-3-providing-a-path\">Step 3 &#8211; Providing a path<\/h3>\n\n\n<p><span style=\"font-weight: 400;\">This part is simple, we just need to connect our alligator clips between all of the components on our circuit. If you do this correctly, then your LED will shine bright! Remember, when connecting wires to a battery, always connect the positive end first, then the negative. Check out the picture below for how it all needs to be connected together.<\/span><\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-medium wp-image-493\"><img decoding=\"async\" src=\"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-content\/uploads\/eagle\/2017\/02\/circuit-1-300x236.jpg\" alt=\"circuit-alligator-clips\" class=\"wp-image-493\"\/><figcaption class=\"wp-element-caption\"><em>Our electricity now has a path to flow through with the added alligator clips<\/em><\/figcaption><\/figure>\n\n\n<h2 class=\"wp-block-heading\" id=\"types-of-circuits\">Types of circuits<\/h2>\n\n\n<p><span style=\"font-weight: 400;\">Now, before you go running off into the wild and building your own circuits, you need to know about two ways to describe a circuit, one of which might ruin your circuit&#8217;s day.<\/span><\/p>\n\n\n\n<p>Circuits can be arranged as series and parallel circuits. Understanding the differences between series and parallel configurations, including the specific benefits of parallel configurations, is essential for effective circuit analysis and design.<\/p>\n\n\n<h3 class=\"wp-block-heading\" id=\"closed-circuit-or-open-circuit\">Closed circuit or open circuit<\/h3>\n\n\n<p><span style=\"font-weight: 400;\">A circuit is considered a <\/span>closed circuit<span style=\"font-weight: 400;\"> when there is a complete path available for electricity to travel on. This is also referred to as a complete circuit. Now, if your circuit isn\u2019t working as intended, then this means that it\u2019s an <\/span>open circuit<span style=\"font-weight: 400;\">. This can be caused by several things, including a loose connection or a broken wire.<\/span><\/p>\n\n\n\n<p><span style=\"font-weight: 400;\">Here\u2019s an easy, visual way to understand the difference between a closed or open circuit, check out the circuit diagram below and notice that it\u2019s the same circuit we made above, except now it has a switch.<\/span><\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter wp-image-494 size-medium\"><img decoding=\"async\" src=\"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-content\/uploads\/eagle\/2017\/02\/2017-02-22_17-25-51-300x293.png\" alt=\"open-circuit\" class=\"wp-image-494\"\/><figcaption class=\"wp-element-caption\"><em>Here\u2019s a diagram of the circuit we made above. Notice the addition of a switch.<\/em><\/figcaption><\/figure>\n\n\n\n<p><span style=\"font-weight: 400;\">Right now, the switch is up, and you\u2019ll see that electricity doesn&#8217;t have a smooth path to flow through since the switch is breaking the connection. This is an open circuit. But what happens if you flip the switch?<\/span><\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-medium wp-image-495\"><img decoding=\"async\" src=\"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-content\/uploads\/eagle\/2017\/02\/closed-circuit-300x293.png\" alt=\"closed-circuit\" class=\"wp-image-495\"\/><figcaption class=\"wp-element-caption\"><em>Now our switch is triggered, which completes the circuit, allowing electricity to flow to our LED!<\/em><\/figcaption><\/figure>\n\n\n\n<p><span style=\"font-weight: 400;\">Aha! Now you just created a complete path for your electricity to travel on, and your LED will turn on! This is a closed circuit. <\/span>In a closed circuit, the algebraic sum of the potential differences around the loop is zero, which is a key principle in circuit analysis.<\/p>\n\n\n<h3 class=\"wp-block-heading\" id=\"short-circuit\">Short Circuit<\/h3>\n\n\n<p><span style=\"font-weight: 400;\">Then there\u2019s the <\/span><b>short circuit<\/b><span style=\"font-weight: 400;\">. When you don\u2019t give your circuit any work to do, but you still provide some power, prepare for some problems. Check out our circuit below, we took out the LED, resistor, and switch, leaving just our copper wire and battery.<\/span><\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter wp-image-496 size-full\"><img decoding=\"async\" src=\"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-content\/uploads\/eagle\/2017\/02\/5113f781ce395f877e000005.png\" alt=\"short-circuit\" class=\"wp-image-496\"\/><figcaption class=\"wp-element-caption\"><em>Here\u2019s a circuit well on its way to becoming a short circuit! Without any work to do this battery will soon burn out.<\/em><\/figcaption><\/figure>\n\n\n\n<p><span style=\"font-weight: 400;\">If we hook this thing together in its physical form, then the battery and wire are going to get super hot, and eventually, the battery will run out of juice. Why does this happen? When you give electricity some work to do in a circuit like lighting an LED or spinning a motor, then this limits how much electricity will flow through your circuit.<\/span><\/p>\n\n\n\n<p><span style=\"font-weight: 400;\">But the minute you take any of that work out of your circuit, the electricity goes crazy and runs around its path at full speed without anything holding it back. If you let this happen for an extended period of time, then you\u2019ll find yourself with a damaged power supply, a drained battery, or maybe something even worse, like a fire!<\/span><\/p>\n\n\n\n<figure class=\"wp-block-image aligncenter size-medium wp-image-497\"><img decoding=\"async\" src=\"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-content\/uploads\/eagle\/2017\/02\/ShortCircuit_DSC_7873_H1-300x286.jpg\" alt=\"short-circuit-fire\" class=\"wp-image-497\"\/><figcaption class=\"wp-element-caption\"><em>Whoa! Don\u2019t try this at home. Here\u2019s a hefty 12v lantern battery being short-circuited in the name of science. (<a href=\"https:\/\/www.exploratorium.edu\/snacks\/short-circuit\">Image source<\/a>)<\/em><\/figcaption><\/figure>\n\n\n\n<p><span style=\"font-weight: 400;\">So if you ever work with a circuit and your wire or battery is getting super hot, then <\/span>turn everything off immediately <span style=\"font-weight: 400;\">and look for any short circuits. <\/span><\/p>\n\n\n<h2 class=\"wp-block-heading\" id=\"the-humble-circuit-and-its-place-in-our-world-of-electronics\">The humble circuit and its place in our world of electronics<\/h2>\n\n\n<p><span style=\"font-weight: 400;\">There you go, young electronics master, you now have all the information you need to control the humble circuit. By understanding how a circuit works, you\u2019ll soon be able to tackle projects of all shapes and sizes. As you move forward, practice analyzing circuits using different methods, try designing circuits for your own applications, and always review all the data to ensure your calculations are accurate and complete.<\/span> <span style=\"font-weight: 400;\">But before beginning your own journey, remember the Guiding Rule of Threes:<\/span><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Rule 1 <\/strong>&#8211; <span style=\"font-weight: 400;\">Electricity will always want to flow from a higher voltage to a lower voltage.<\/span><\/li>\n\n\n\n<li><strong>Rule 2<\/strong> &#8211; <span style=\"font-weight: 400;\">Electricity always has work that needs to be done.<\/span><\/li>\n\n\n\n<li><strong>Rule 3<\/strong> &#8211; <span style=\"font-weight: 400;\">Electricity always needs a path to travel on.<\/span><\/li>\n<\/ul>\n\n\n\n<p><span style=\"font-weight: 400;\">And if your circuit ever gets super hot, shut it down! You\u2019ve got a short circuit.<\/span><\/p>\n\n\n\n<p><span style=\"font-weight: 400;\">Ready to build your first circuit today?<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Learn the three basic rules of how a circuit works including voltage flow, loads, and conductive materials.<\/p>\n","protected":false},"author":3911,"featured_media":22182,"menu_order":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":""},"categories":[359],"tags":[207,206],"coauthors":[589],"class_list":["post-17624","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-electronics-engineering","tag-electronics","tag-pcb","dhig-theme--light"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.4 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>The 3 Rules of How a Circuit Works (2024 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Treau is rethinking thermal comfort appliances by creating high efficiency, low-carbon natural refrigerants on the inside; quiet, low-profile, and easy to install on the outside."},{"@type":"BreadcrumbList","@id":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/3-rules-humble-circuit-place-world-electronics\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/"},{"@type":"ListItem","position":2,"name":"The 3 Rules of How A Circuit Works (2024 Update)"}]},{"@type":"WebSite","@id":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/#website","url":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/","name":"Fusion Blog","description":"Product updates, tips, tutorials and community news.","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Person","@id":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/#\/schema\/person\/81f7fc85212bfa6e804abcca6343e62a","name":"Edwin Robledo","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-content\/uploads\/2025\/01\/edwin-headshot-150x150.jpg99104a7458ebc06e35b3a1ab1af8476c","url":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-content\/uploads\/2025\/01\/edwin-headshot-150x150.jpg","contentUrl":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-content\/uploads\/2025\/01\/edwin-headshot-150x150.jpg","caption":"Edwin Robledo"},"description":"I began my career in the communications industry, primarily with the implementation of fiber optics communications and data management. I joined the EAGLE team 25 years ago to satisfy my passion for being involved with circuit board designs. I\u2019m the Technical Marketing Engineer for Fusion 360 electronics and part of the Fusion 360 community team. I have published best practices articles, Blogs, hundreds of video tutorials, and hosted several electronic design bootcamps. My passion is anything related to the outdoors, especially outdoor photography and hiking.","url":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/author\/edwin-robledo\/"}]}},"_links":{"self":[{"href":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-json\/wp\/v2\/posts\/17624","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-json\/wp\/v2\/users\/3911"}],"replies":[{"embeddable":true,"href":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-json\/wp\/v2\/comments?post=17624"}],"version-history":[{"count":0,"href":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-json\/wp\/v2\/posts\/17624\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-json\/wp\/v2\/media\/22182"}],"wp:attachment":[{"href":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-json\/wp\/v2\/media?parent=17624"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-json\/wp\/v2\/categories?post=17624"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-json\/wp\/v2\/tags?post=17624"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/www.autodesk.com\/products\/fusion-360\/blog\/wp-json\/wp\/v2\/coauthors?post=17624"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}