Back

What Are Transistors?

5 March 2026

Tiny Switches Powering Our Digital World

When you think about your phone, laptop, or even your electric toothbrush, you might not realise what makes them work. At the heart of it all is something so small we’re talking atomic scale and you’d need an electron microscope to see it – it’s the transistor. But what is a transistor? 

A transistor is an electric switch. It’s no ordinary switch; it’s capable of controlling electrical currents with incredible precision.

From Bulky Vacuum Tubes to Tiny Transistors

Before transistors revolutionised technology, computers relied on vacuum tubes—think of them as fragile glass bulbs that switched electricity on and off. These tubes were bulky, power-hungry, and prone to overheating, which meant early computers like ENIAC were enormous and unpredictable. A sneeze near one could cause a crash!

In 1947, the transistor arrived and changed everything. Imagine upgrading from a coal-powered steam engine to a sleek Tesla overnight. Transistors are tiny, fast, energy-efficient, and tough. They don’t need to warm up, don’t burn out easily, and certainly don’t require a dedicated cooling room.

How Do Transistors Work?

Think of a transistor as a tap for electricity—you can turn the current on or off. Imagine billions of these taps packed onto a chip no bigger than your fingernail. Connect them correctly, and you have a microprocessor capable of running complex apps, games, and even artificial intelligence. It’s the microprocessor that powers everything from TikTok to your computer’s homework apps (and yes, even that frustrating moment when you forget to save).

Why Transistors Matter: Logic Gates and CPUs

Transistors build logic gates—tiny electronic “bouncers” that decide whether electricity can pass through based on simple rules. An AND gate only says “yes” if both inputs agree, while a NOT gate acts like the sarcastic mate who always says the opposite. Combine enough of these gates, and you get a CPU, the brain of every computer.

Every app, every game, and every AI-powered tool is the result of trillions of these on/off decisions happening every second—a dazzling electric light show that’s the foundation of modern life.

Final Thoughts

So, next time you hear someone say “we’re living in the future,” remember to thank the tiny transistor. This small but mighty invention replaced room-sized vacuum tubes with microchips.

Want to know more? Check out our Lesson Hacker YouTube video 

For more Lesson Hacker videos, check out the CraignDave YouTube playlist HERE.

Visit our website to explore more cutting-edge tech-transforming news in the computer science world!

 

Related posts

Do we need government AI copyright laws?

AI is transforming creativity — but are we protecting the people behind the art? We explore the UK’s heated debate over AI copyright laws and what they mean for creators and innovation.

8 April 2026

How Do Map Apps Work?

Discover how your map app uses graph theory and clever algorithms to find the fastest route, even before you spot the traffic jam. It’s the smart tech behind every turn and reroute you trust.

What is Chip Binning?

Chip binning is how manufacturers sort silicon chips based on their performance, turning some into high-speed processors and others into more modest models. It’s like baking cookies—some come out perfect, others just good enough.

Meet Dodona: A powerful coding platform built for real classrooms

Discover how Dodona is transforming programming lessons with a powerful, classroom-ready platform built by educators. With the integration of Time2Code, it’s never been easier to deliver engaging, structured coding lessons while saving time and reducing hassle.

Students looking at a hill to climb.

Goals version 2

Until now, the Terms goal has used the Leitner system to determine what students should complete each week. This approach […]

4 April 2026

Differentiation is dead

For decades, teachers were told that differentiation was the golden ticket. If we could just tailor the right task to […]

3 April 2026

It’s not in the mark scheme

Just because it’s not in the mark scheme doesn’t mean it’s wrong — Quicksort proves there are often multiple valid ways to reach the same correct answer.
Understanding the principles behind algorithms matters far more than memorising a single “approved” method.

27 March 2026

Festival Of Computing OCR Fringe Event 2026

The Festival of Computing 2026, co-founded and hosted by Bromsgrove School with AQA as headline sponsor, is the UK’s ultimate […]

24 March 2026

VEX Robotics is inspiring the next generation of Computer Scientists

If you’ve ever wondered how to make computing more engaging for your students, you need to know about VEX Robotics.  […]

18 March 2026