Part 6/7:
Imagine a water faucet with a lever controlling water flow.
The water pressure represents the electron flow.
Moving the lever back and forth doesn’t generate pressure; instead, it modulates how much water passes through.
The root of the analogy: The heater is like the water source producing a steady flow; the grid is like the lever controlling the flow; and the plate is like the outlet where the water (or electrons) is collected.
This analogy emphasizes that vacuum tubes, particularly through their grid controlling electron flow, act as modulators—creating stronger signals from weaker inputs—a fundamental feature that paved the way for modern electronics.