IT REALLY
WORKS!try it ↓
WORKS!try it ↓
MItem 24-1066
Drag a knob up or down, scroll on it, or click its left or right side.
Drag a knob up or down, scroll on it, or click its left or right side.
An oscilloscope draws electricity. Inside the tube a beam of electrons lights a dot on the phosphor; one pair of plates sweeps it steadily from left to right, another pushes it up and down with the signal. Sweep often enough and the dot becomes a steady line: the shape of the voltage.
The screen is ruled in squares, and the two big switches say what a square is worth: so many volts up, so many milliseconds across. Count the squares and you have measured the signal. A wave that repeats every 1 ms has a frequency of 1 kHz.
The trigger is what makes the picture stand still. Each sweep waits until the signal crosses a chosen level, so every pass draws the wave in the same place. Set the level outside the wave and, on the usual automatic setting, the sweeps start anywhere and the picture runs.
In X-Y mode a second signal drives the beam sideways instead of the steady sweep. Two waves whose frequencies are in a simple ratio draw Lissajous figures, an old way to compare frequencies by eye.