The simplest oscilloscope from a computer

December 9, 2017 Simple circuits / DIY electronics / Computer DIY 108 085 13

It is no secret that beginner hams do not always have expensive measuring equipment at hand. For example, an oscilloscope, which even in the Chinese market, the cheapest model costs about several thousand.
Sometimes an oscilloscope is needed to repair various circuits, check distortion of an amplifier, tune audio equipment, etc. Very often, a low-frequency oscilloscope is used to diagnose the operation of sensors in a car.
In this series, the simplest oscilloscope made from your personal computer will help you. No, your computer does not have to be disassembled and modified in any way. You just need to solder the prefix, the divider, and connect it to the PC via the audio input. And to display the signal, install special software. In just a couple of tens of minutes, you will have your own oscilloscope, which may well be suitable for signal analysis. By the way, you can use not only a stationary PC, but also a laptop or netbook.
Of course, such an oscilloscope with a stretch is comparable to a real device, since it has a small frequency range, but the thing in the household is very useful to see the amplifier output, various ripples of power supplies, etc.

Prefix scheme

The simplest oscilloscope from a computer

Agree that the circuit is incredibly simple and does not require much time to assemble it. This divider is a limiter that protects the sound card of your computer from dangerous voltages that you might accidentally fall into the input. The divider can be 1, 10 or 100. The sensitivity of the entire circuit is controlled by a variable resistor. The set-top box is connected to the line input of the PC sound card.

We collect the prefix

You can take a battery box like me or another plastic case.

Software

The program “oscilloscope” will visualize the signal applied to the input of the sound card. I will offer you two options for downloading:
1) A simple program without installation with a Russian interface, download.

[329.85 Kb] (downloads: 9777)

2) And the second with the installation, you can download it - .

Which one to use - you choose. Take and install both, and there you will choose.
If you already have a microphone installed, then after installing and starting the program, you can already observe the sound waves that enter the microphone. It means everything is OK.
For the console, no drivers are needed anymore.
We connect the prefix to the linear or microphone input of the sound card and use it for health.

If you have never had any experience working with an oscilloscope in your life, then I sincerely recommend that you repeat this homemade work and work with such a virtual device. The experience is very valuable and interesting.

Watch a video on working with an oscilloscope for a computer

come back

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#1 feelloff Guests December 9, 2017 3:14 p.m.
7

Also very informative:
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1. #2 Mukhamet Guests March 28, 2018 07:46
  3
  
  excellent, but there is the possibility of connecting to a mobile phone would be generally good
  
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2. #3 Andrei Guests February 1, 2019 12:53
  0
  
  And what voltage to which connectors to connect? How to determine the current strength and voltage at the connectors? On the diagram in the article there is a 1k resistor, but not in the video! How so?
  
  In general, I think, for the first oscilloscope, it will do! Why not!
  
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#4 Basil Guests December 9, 2017 3:38 p.m.
1

Respected! do not call the common wire "ground", On your circuit there is no designation "ground" "ground" "Ground" Yu, Respectfully.
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#5 Sanya Guests 10 December 2017 10:01
5

Very good! Already done! Thing! Where have you been before)) Thank you!
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#6 Pavel Guests January 16, 2018 10:11
5

Vasily - for a long time EARTH is a "common wire". So shorter. There are also: "digital ground", "analog ground", "floating ground". Take any bourgeois scheme - and you will see GND, i.e. Ground, although this is not about grounding. Also the same. as the concept of "digital" does not apply only to decimal digits in the form of text
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#7 wonderful, Guests March 27, 2018 13:28
0

wonderful, but it’s possible to connect to a mobile phone, if possible, tell me
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#8 Guest Michael Guests August 1, 2018 19:34
0

Bandwidth ?
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#9 Guest Alexander Guests August 23, 2018 20:00
0

The sound card input is shunted by two chains of unidirectionally connected diodes in series. The chains themselves are included towards each other. This makes no sense! Why does no one comment on this "novelty"?
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1. #10 amateur Guests September 26, 2018 15:10
  1
  
  diodes limit the input signal for the sound card to about 2.8 V if you foolishly give 220 to the input of the set-top box. They do not affect the signals of lower amplitude
  
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2. #11 Dima Guests November 18, 2018 11:29
  3
  
  Alexander, you are a batan.
  
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#12 acmajor Guests February 8, 2019 18:39
1

https://www.drive2.com/c/505834723478602433/ link to a similar article for the phone. There you can scale the axes with your fingers on the screen and do not need any pens on the screen. With limiting diodes - this is correct. Since there is a resistive divider in the circuit, I think it’s better to remove the variable otherwise than to measure the input voltage (when the variable is adjusted, the voltage calibration is lost).
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#13 Guest Eugene Guests June 17, 2019 09:10
0

I read and remember, but does this circuit work as a closed entrance? Suppose I need to measure the signal level in the RS-485 interface, large distances, there are attenuation, in order to understand in which area I should put the converter to "hold" a sufficient level.
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