We are independent & ad-supported. We may earn a commission for purchases made through our links.

Advertiser Disclosure

Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.

How We Make Money

We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently from our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is a Diode Circuit?

By Andrew Burger
Updated May 16, 2024
Our promise to you
EasyTechJunkie is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At EasyTechJunkie, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

A diode circuit is any of a variety of electrical circuits that take advantage of the distinguishing characteristics of diodes. A class of crystalline semiconductors with two terminals, diodes exhibit a strong bias toward carrying an electrical charge "forward" in one direction while all but completely inhibiting it in the other. Diode circuits are commonly used in power supply applications to convert alternating current (AC) to direct current (DC) and to tune TV and radio receivers. They are also used as analog and digital logic switches, as capacitors to temporarily store and increase electrical charge, in surge protectors to prevent voltage spikes from damaging equipment, and as sensors to detect light and to produce light. Besides rectifier diodes, other common types include light emitting diodes (LEDs), varicap diodes, and Zener diodes.

Diodes were the first semiconductor electronic devices to be invented. Used widely in the electronics industry, they are usually made of silicon, though germanium is used as well. The electrical resistance of a diode circuit is minimal in the forward direction, from the anode to the cathode, hence the term "forward bias." Silicon diodes, for instance, have a 0.6-0.7 volt voltage drop, the threshold point, when carrying current in the forward direction. A relatively high minimum voltage must be reached for current to flow through a diode in the reverse direction. It is these properties that make diode circuits very useful in a wide variety of electronic devices.

In a diode circuit, a diode may be connected to any of a wide variety of other electrical or electronic devices — capacitors, resistors, transformers, power supplies, etc. — depending on the application. Diodes in circuits may be arranged in series or in parallel. An initial application of a diode circuit, one still in widespread use today, is the switching of analog signals. In the early days of digital computing, diode circuits were used to perform the digital logic operations AND and OR.

Of the many different types of diodes used in circuits, LEDs produce light of visible and non-visible frequencies when current passes between the electrodes. Varicap, or varactor, diodes are used to tune radio and TV receivers. Another type, the photodiode, detects light. They typically operate in reverse bias and are used to generate electricity and in solar photovoltaic cells. Zener diodes also operate in reverse bias and are used widely in power supplies to regulate voltage by producing a stable reference voltage.

EasyTechJunkie is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.

Discussion Comments

By David09 — On Jan 28, 2012

@hamje32 - That’s a decent analogy but it’s not perfect. If I understand the article correctly, it’s not that voltage can’t under any circumstances flow in the reverse direction. It’s that it has to be very high to do so.

Apparently there is some threshold you have to reach for that to happen. At any rate it’s been a long time since I looked at circuit diagrams.

One thing I remember is that the symbols for the diodes used arrows to represent the direction of the current flow. Clearly you need to know which way the current is flowing if you’re going to use them effectively in your application.

By hamje32 — On Jan 27, 2012

@everetra - It seems like the laser diode circuit acts like a check valve in one sense. A check valve is a mechanical device to allow water to flow in one direction only.

The valve closes so that water cannot flow back into the same direction. In the same way, the LED circuit has a “forward bias.” Current will flow in one direction and not the other.

I can see how this would be useful as a safety protection mechanism. By preventing circuits from flowing the opposite direction you can prevent voltage kickbacks, so to speak. I don’t know if that’s a technical term but that’s how I visualize it.

By everetra — On Jan 26, 2012

I remember the first time I saw an LED diode circuit in operation. It looked like a string of Christmas lights, except that the LED bulbs had a more permanent quality to the lights, as if they could just stay on forever. The LED didn’t flicker on and off.

This was in the early days of LED electronics many years ago. Years later, LED technology has pretty much become a staple in so many applications. They have LED televisions nowadays which supposedly deliver the ultimate in color and picture quality, each LED light representing a pixel on the screen.

So it’s a lot better than LCD and even plasma technology. Of course the technology keeps changing. Soon LEDS will become passé in television too.

EasyTechJunkie, in your inbox

Our latest articles, guides, and more, delivered daily.

EasyTechJunkie, in your inbox

Our latest articles, guides, and more, delivered daily.