Oscilloscopes are used to represent graphically in a scale the electric potential over time.
The device is divided in three parts: the cathode ray tube (CRT), vertical controls and horizontal controls.
However, externally, we can only see the screen, in which the cathode ray tube ends, and some other controls, which allow us to modify the intensity and position of the image, to control the amplitude of the displayed signal and to adjust the time base.
The combination of both movements makes the electrons influence different parts of the screen, drawing on it a curve which will make as aware of the potential variation over time.
The first oscilloscope of cathode ray tube was developed in 1897, as a laboratory curiosity without any useful application, by the German physicist Karl Ferdinand Braun.
Its commercialisation as a measurement instrument started in 1946, with the Tektronix model, patented by Howard Vollum and Melvin “Jack” Murdock.