Analog vs Digital Oscilloscopes (Overview)

Analog vs Digital Oscilloscopes

The oscilloscope is a graphic display instrument in which you can see the electrical signals and their variations over time.

The values ​​of the electrical signals are represented in the form of coordinates on the oscilloscope screen, where normally the X-axis (horizontal) represents time, and the Y-axis (vertical) represents the electrical signals (voltages). The image obtained by the device is called an oscillogram.

According to its internal operation, the oscilloscopes can be analog or digital.

Types Of Oscilloscopes

As with the vast majority of measuring equipment, analog and digital oscilloscopes can be achieved on the market, which, in theory, provide the same results. However, according to what needs to be measured, one or the other is preferable.

Each has its advantages and disadvantages, clarifying that, unlike other electronic equipment, the analog oscilloscope does not lose its validity since it is ideal when you want to observe rapid variations of the input signal in real-time.

Analog oscilloscope

Work directly with the applied signal. The signal, once amplified, deflects a beam of electrons vertically, proportional to its value. Work with continuous variables.

However, the main disadvantage is that to observe a stable trace a periodic signal is required since it is such periodicity that allows the formation of the trace. On the other hand, if the signal is too slow, no trace is formed. In the best case, a point is seen, as in radars.

Digital oscilloscope

Use an analog-digital converter to digitally store the input signal. Subsequently, reconstruct said signal on the screen. On the other hand, digital is preferable when the measurement is made on non-repetitive events, such as voltage peaks that occur randomly.

Digital phosphor oscilloscope

This is one of the cases in which it is possible to obtain the best of both worlds: the digital phosphor oscilloscope combines the best of the analog and digital oscilloscope, combining the characteristics of both, adding special functions and dispensing with the lightning tube cathodic.

Oscilloscope Utility

Incredible as it may seem, oscilloscopes have multiple uses: from a doctor to a TV repair technician, you can conveniently use this viewing instrument.

Thanks to the ability to transform a physical magnitude into an electrical signal, the oscilloscope can perfectly give the value of blood pressure or heart rate, can measure the power of a particular sound or the level of vibrations in a car, and even determine where a circuit fails.

What To Do With A Digital Oscilloscope?

With the oscilloscope you can:

  • Detect the fault in a circuit.
  • Determine the noise of the signals and how long they last over time.
  • Measure the phase between two signals.
  • Determine the period and voltage of a signal.
  • Determine, indirectly, the frequency of a signal.
  • Determine which part of the signal refers to alternating current (AC) and which part to direct current (DC).

How To Use An Oscilloscope Correctly

Before making any measurement it is necessary to make the following basic settings:

Check the size of the voltage signal, that is, attenuate or amplify said voltage, for this, you must use the AMPL command.

Adjust the timebase (the oscilloscope measures the voltage determined in a given time cycle). In the case of having repetitive signals, the ideal will be that at least two cycles can be observed on the screen.
Stabilize repetitive signals as well as possible.

How Much Does An Oscilloscope Cost?

Analog oscilloscopes are usually tabletop, therefore, they are medium-sized devices. Its price can range between 400 and 1,500 euros, while digital models, both those that are portable and those that are not, are smaller and have a cost that can be between 200 and 1000 euros, depending on their capacity of storage.

When buying an oscilloscope, it is always good to verify the bandwidth, the rise time, the vertical sensitivity, the speed, and the accuracy in the gain and in the base of the times, aspects that will allow to compare the different capacities of the device


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