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 of 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 are the Basics of Anode Voltage?

By Sean Quinn
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.

Anode voltage is the concept that makes vacuum tube technology work. It is what causes vacuum tubes to be able to perform their two main functions of amplification and rectification. Semiconductor technology is made possible because of this.

If a piece of metal is heated, it emits electrons, which carry a negative electrical charge. Charged particles are attracted to particles that carry an opposite charge and repel those with a similar charge. When a piece of metal emits electrons, it then carries a charge that is positive with respect to those electrons. This causes the electrons to return to the metal, because they are attracted to its opposite charge. This results in a cloud of electrons around the metal, which is known as a space charge.

A vacuum tube takes advantage of this effect, and it contains a metal plate called a cathode, which is heated. A second metal plate is added, called an anode, and when a positive charge is applied to the anode, it attracts the electrons emitted by the cathode, and current flows through the vacuum tube. This applied charge is called the anode voltage, and when it is positive, it causes current to flow faster and is called forward bias. When the anode voltage is negative, it opposes current flow and is called reverse bias. This last property, which allows current to flow in only one direction through the vacuum tube, is called rectification.

A tube with two plates is called a diode. Adding a third plate in the middle produces a triode and allows the tube to amplify an electrical signal. This third plate is called a control grid and is a mesh of wires that the electrons pass through on their way from the cathode to the anode. The grid is closer to the cathode, so any voltage applied to the grid magnifies the effects of creating or opposing current flow. So, small changes to the grid voltage create larger changes in the current flow across the tube.

A problem with this design is that, as the current is amplified across the tube, it causes changes in the anode voltage. This in turn affects the anode current and keeps the tube from amplifying at its full potential. A fourth element, called the screen grid, was added to minimize this effect.

The screen grid created a new problem, however — when the anode voltage would go lower than the screen grid voltage, electrons would flow from the anode to the screen grid. This caused a distorted output signal. The solution was to add another grid, called a suppressor grid. It is biased at the same voltage as the cathode and repels any emissions from the anode. This kind of five-element vacuum tube is called a pentode.

Transistors are three-element semiconductors that operate in a similar fashion as a triode, although the actual names "anode" and "cathode" are used only in certain types of transistor. The programmable unijunction transistor is one such example. Semiconductors serve the same functions of amplification and rectification, but their ability to do so in a much smaller package and with lower power requirements is what enables modern electronic and computer technologies.

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
EasyTechJunkie, in your inbox

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

EasyTechJunkie, in your inbox

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