The Oscilloscope is a type of electronic test instrument that allows observation of analog signals usually as a two-dimensional graph - the dependence of voltage (Y-axis, vertical) on time (X-axis, horizontal).
The types of oscilloscopes:
- analog oscilloscopes
- analog-digital oscilloscopes
- digital storage oscilloscopes
- mixed signal oscilloscopes
Analog oscilloscopes are based on the use of cathode-ray tube and ramp sweep generator with linearly varying voltage.
Ilustration showing the interior of a cathode-ray tube for use in an oscilloscope:
- Deflection voltage electrode
- Electron gun
- Electron beam
- Focusing coil
- Phosphor-coated inner side of the screen
Analog-digital oscilloscopes are based on the use of cathode-ray tube and ramp sweep generator with linearly varying voltage and also built-in storage device to keep one or several pictures. Not so widely used nowadays.
Digital storage oscilloscope (DSO) is an oscilloscope which stores and analyses analog signals digitally rather than using analogue techniques. It is now the most common type of oscilloscope in use because of the advanced trigger, storage, display and measurement features which it typically provides.
Mixed signal oscilloscopes are based on the high-speed digitization of analog input signals and the entry of numerical orders, the storage of data and its display (on LCD, as a rule) in the general time scale. The most fast-developing oscilloscope type at the moment.