PC oscilloscope

Already two years ago, I was interested in a small program promising to create a two-channel oscilloscope from a PC with a sound card. Since the oscilloscope is a very good helper in animating almost anything, I downloaded the program and still use it today. So what can he do??
Program “Oscilloscope for Windows95, version 2.51” written by Konstantin Zeldovich and is freeware, that is, it is freely distributable. It replaces a two-channel oscilloscope with a spectrum analyzer and a correlometer. It can also work in XY mode in order to draw Lissajou figures – phase shift measurements.

It covers the frequency band from 20Hz to 20kHz, the maximum input voltage is about 2V (according to the sound card). The image is redrawn approximately 6 times per second (according to PC performance) and the measured data can be saved to a file.

System requirements are minimal – processor 486 and better, at least an 8-bit sound card, W95. You will lose something more on the disk 150!!! kB. For decent work, I recommend making a simple connecting cable with measuring tips. We connect to the other side 3,5 inch stereo jack. You have to be careful, so that we do not introduce an extremely strong signal to the input of the sound card, which could damage it.

It will be displayed after starting the program “the front panel of the oscilloscope”. You can change the gain using the mouse or keyboard, time constant of the base, synchronization, synchronization method, delay…

When measuring non-sine signals, we may be interested in the content of higher harmonics. This is what the integrated spectrum analyzer is for. If we move the cursor to the oscilloscope screen, in the bottom line we will see both the frequency and the level.

Sometimes we are interested in the relationship between two signals – for example when measuring amplifier distortion. We feed the signal from the generator to one input of the oscillator, to the second output from the amplifier. We will find out the fidelity of amplification with a correlometer.

In XY mode, it is possible to measure the phase shift using Lissajous patterns. There is a grid on the screen, which will make it easier for us to read from the screen. Care must be taken to set the same gain for both channels, or recalculate.

There is very high-quality documentation for the program (in English). You can download the program here: osc251.zip (88kB).