The simplest oscilloscope from a computer
It is no secret that novice radio amateurs do not always have at hand expensive measuring equipment. For example, an oscilloscope, which even in the Chinese market, the cheapest model costs about a few thousand. It happens that an oscilloscope is needed to repair various circuits, check amplifier distortions, tune sound equipment, etc. Very often, a low-frequency oscilloscope is used to diagnose the operation of sensors in a car. In this case, a simplest oscilloscope made from your personal computer will help you. No, your computer does not have to be dismantled and modified. All you need is to solder a prefix divider, and connect it to a PC via the audio input. And to display the signal to install a special software. For a couple of tens of minutes you will have your own oscilloscope, which may well fit for signal analysis. By the way, you can use not only a stationary PC, but also a laptop or a netbook. Of course, such an oscilloscope is very expensive compared to a real device,since it has a small frequency range, but the thing on the farm is very useful to watch the output of the amplifier, various pulsations of power supplies, etc.Agree that the circuit is incredibly simple and does not require much time to assemble it. This delimiter is a limiter that will protect your computer's sound card from dangerous voltage, which you can accidentally fall on the input. The divider can be 1, 10 and 100. The variable resistor adjusts the sensitivity of the entire circuit. The prefix is connected to the line input of the PC sound card.