Resistors, Capacitors, Transistors
Three components form the foundation of nearly all electronics. RESISTORS limit current flow. CAPACITORS store electric charge briefly. TRANSISTORS act as switches or amplifiers. Combinations of these (and a few others — diodes, inductors) build everything from radios to phones to spacecraft. Modern microchips contain BILLIONS of transistors in spaces smaller than a fingernail.
Each component. RESISTORS: oppose current flow, used to control voltage and current. Color bands on the body indicate the value. Used everywhere — to dim LEDs, set timing, divide voltages. CAPACITORS: store electrical energy in an electric field, briefly. Used to smooth power supplies, filter signals, store energy for camera flashes. TRANSISTORS: control current flow with a small input signal. Can act as a SWITCH (on/off — basis of digital electronics) or AMPLIFIER (small signal controls big signal — basis of audio, radio).
Modern smartphones contain BILLIONS of TRANSISTORS in their CPU. What do those transistors fundamentally do?
How small? In 1947, the first transistor was the size of a hand. Today's leading transistors (3 nanometer node) are smaller than viruses. A modern smartphone CPU has 10-20 BILLION transistors. The smallest commercially manufactured features are now atoms-wide. Approaching physical limits has driven new approaches — 3D stacking, new materials, neuromorphic chips.
Identify Components
Look at any old electronic device (a circuit board, perhaps from a broken radio or computer). You will see resistors (small cylindrical things with stripes), capacitors (cylinders or discs), and transistors (small black components with 3 legs). Each has a specific job.
Three little components. They built the modern world. From the simplest radio to the most powerful supercomputer, these are the bricks.
Want to keep learning?
Sign up for free to access the full curriculum — all subjects, all ages.
Start Learning Free