The simplest oscilloscope from a computer

It's no secret that beginning radio amateurs don't always have expensive measuring equipment at hand. For example, an oscilloscope, which even on the Chinese market, the cheapest model costs about several thousand.
Sometimes an oscilloscope is needed to repair various circuits, check amplifier distortion, adjust audio equipment, etc. Very often, a low-frequency oscilloscope is used to diagnose the operation of sensors in a car.
In this case, a simple oscilloscope made from your personal computer will help you. No, your computer will not have to be disassembled and modified in any way. All you need to do is solder the console - a 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 analyzing signals. By the way, you can use not only a desktop PC, but also a laptop or netbook.
Of course, such an oscilloscope is hardly comparable to a real device, since it has a small frequency range, but it is a very useful thing in the household for viewing the output of an amplifier, various ripples of power supplies, etc.

Set-top box diagram

Agree that the circuit is incredibly simple and does not require much time to assemble. This is a divider - a limiter that will protect your computer's sound card from dangerous voltage that you may accidentally drop into the input. The divider can be 1, 10 or 100. A variable resistor adjusts the sensitivity of the entire circuit. The set-top box is connected to the linear input of the PC sound card.

Assembling the console

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

Software

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


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

Which one to use is up to you. Take and install both, and then choose.
If you already have a microphone installed, then after installing and launching the program you will be able to observe the sound waves that enter the microphone. It means everything is OK.
The set-top box no longer requires any drivers.
We connect the set-top box to the linear or microphone input of the sound card and use it for good measure.

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

Watch a video on working with an oscilloscope for a computer