Eli5: How do oscilloscopes work?

Question

Eli5: How do oscilloscopes work?

In: Technology

Answer 1

Old analog CRT oscopes worked by scanning an electron beam across the CRT. The input voltage would deflect the beam up and down, and the time scale chosen would change the rate at which it scanned left to right. This would give you a “graph” of the input signal.

Of course, modern scopes are more sophisticated. The input goes to an Analog to Digital Converter which samples the input signal rapidly and turns the voltage into a series of numbers. Those can then be displayed at whatever time scale is desired, as long as it is not too fast for the ADC.