A simple oscilloscope from a computer. Oscilloscope via microphone input. DIY oscilloscope from a tablet

It's no secret that beginning radio amateurs don't always have expensive equipment on hand. measuring equipment. 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 it will help you the simplest oscilloscope made from yours personal computer. 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 set 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 sound card PC.

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.

(downloads: 8310)

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

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 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.

An oscilloscope is a device that helps you see the dynamics of oscillations. With its help, you can diagnose various breakdowns and obtain the necessary data in radio electronics. Previously, oscilloscopes based on transistor tubes were used. These were very bulky devices that were connected exclusively to a built-in or specially designed screen.

Today, instruments for measuring basic frequency, amplitude characteristics and signal shapes are convenient, portable and more compact devices. They are often performed as a separate console connected to a computer. This maneuver allows you to remove the monitor from the package, significantly reducing the cost of the equipment.

You can see what a classic device looks like by looking at a photo of an oscilloscope in any search engine. You can also mount this device at home using inexpensive radio components and housings from other equipment for a more presentable appearance.

How can I get an oscilloscope?

Equipment can be obtained in several ways and it all depends solely on the amount of money that can be spent on purchasing equipment or parts.

Buy a ready-made device in a specialized store or order it online;
Buy a construction set, for example, sets of radio components and housings, which are sold on Chinese websites, are now widely popular;
Independently assemble a full-fledged portable device;
Mount only the attachment and probe, and organize the connection to a personal computer.

These options are listed in order of lower hardware costs. Buying a ready-made oscilloscope will cost the most, since it is an already delivered and working unit with all the necessary functions and settings, and in case of incorrect operation, you can contact the sales center.

The designer includes a circuit for a simple do-it-yourself oscilloscope, and the price is reduced by paying only the cost of radio components. In this category, it is also necessary to distinguish between models that are more expensive and simpler in terms of configuration and functionality.

Assembling the device yourself according to existing diagrams and radio components purchased at different points may not always turn out to be cheaper than purchasing a designer kit, so it is necessary to first evaluate the cost of the undertaking and its justification.

The cheapest way to get an oscilloscope is to solder only the attachment to it. Use a computer monitor for the screen, and programs for capturing and transforming the received signals can be downloaded from various sources.

Oscilloscope Designer: Model DSO138

Chinese manufacturers have always been famous for their ability to create electronics for professional needs with very limited functionality and for fairly little money.

On the one hand, such devices are not able to fully satisfy a number of needs of a person involved in radio electronics on a professional basis, however, for beginners and lovers of such “toys” it will be more than enough.

One of the popular Chinese-made models of the oscilloscope design type is considered to be the DSO138. First of all, this device has a low cost, and it comes with all the necessary parts and instructions, so there should be no questions about how to properly make an oscilloscope with your own hands, using the documentation included in the kit.

Before installation, you need to familiarize yourself with the contents of the package: board, screen, probe, all necessary radio components, assembly instructions and circuit diagram.

The work is made easier by the presence of corresponding markings on almost all the parts and the board itself, which really turns the process into assembling a children's construction set for an adult. The diagrams and instructions clearly show all the necessary data and you can figure it out even without knowing a foreign language.

The output should be a device with the following characteristics:

Input voltage: DC 9V;
Maximum input voltage: 50 Vpp (1:1 probe)
Current consumption 120 mA;
Signal bandwidth: 0-200KHz;
Sensitivity: electronic bias with vertical adjustment option 10mV/div - 5V/Div (1 - 2 - 5);
Discrete frequency: 1 Msps;
Input resistance: 1 MOhm;
Time interval: 10 µs / Div - 50s / Div (1 - 2 - 5);
Measurement accuracy: 12 bits.

Step-by-step instructions for assembling the DSO138 construction set

Should be considered in more detail detailed instructions for the manufacture of an oscilloscope of this brand, because other models are assembled in a similar way.

It is worth noting that in this model the board comes immediately with a soldered 32-bit Cortex™ microcontroller on the M3 core. It operates two 12-bit inputs with a characteristic of 1 μs and operates in a maximum frequency range of up to 72 MHz. Having this device already installed makes the task somewhat easier.

Step 1. It is most convenient to start installation with SMD components. You need to take into account the rules when working with a soldering iron and a board: do not overheat, hold for no longer than 2 seconds, do not connect different parts and tracks together, use solder paste and solder.

Step 2. Solder the capacitors, inductors and resistances: you need to insert the specified part into the space provided for it on the board, cut off the excess length of the leg and solder it on the board. The main thing is not to confuse the polarity of the capacitors and not to close adjacent tracks with a soldering iron or solder.

Step 3. We mount the remaining parts: switches and connectors, buttons, LED, quartz. Particular attention should be paid to the diode and transistor side. Quartz has metal in its structure, so you need to ensure that there is no direct contact of its surface with the board tracks or take care of the dielectric lining.

Step 4. 3 connectors are soldered to the display board. After completing manipulations with the soldering iron, you need to rinse the board with alcohol without auxiliary products - no cotton wool, discs or napkins.

Step 5. Dry the board and check how well the soldering was done. Before connecting the screen, you need to solder two jumpers to the board. The existing bitten-off pins of the parts will be useful for this.

Step 6. To check operation, you need to connect the device to a network with a current of 200 mA and a voltage of 9 V.

The check consists of taking indicators from:

9 V connector;
Test point 3.3 V.

If all parameters correspond to the required values, you need to disconnect the device from the power supply and install the JP4 jumper.

Step 7. You need to insert a display into the 3 available connectors. You need to connect an oscilloscope probe to the input and turn on the power yourself.

The result correct installation and the assembly will appear on the display with its number, firmware type, version and developer’s website. After a few seconds, you will be able to see sine waves and a scale when the probe is turned off.

Computer console

When assembling this simple device, you will need a minimum number of parts, knowledge and skills. Schematic diagram very simple, except that you will need to make the board yourself to assemble the device.

The size of the attachment for a do-it-yourself oscilloscope will be approximately the size of a matchbox or a little larger, so it is best to use a plastic container or battery box of this size.

Having placed the assembled device with ready-made outputs into it, you can begin organizing work with a computer monitor. To do this, download the Oscilloscope and Soundcard Oscilloscope programs. You can test their work and choose the one you like best.

The connected microphone will also be able to relay sound waves to the connected oscillator, and the program will reflect the changes. This set-top box is connected to a microphone or line input and does not require any additional drivers.

DIY oscilloscope photos

An oscilloscope is a tool that almost every radio amateur has. But for beginners it is too expensive.

Problem high cost The solution is simple: there are many options for making an oscilloscope.

The computer is perfect for such a modification, and its functionality and appearance will not be harmed in any way.

Device and purpose

The circuit diagram of an oscilloscope is difficult for a novice radio amateur to understand, so it should not be considered as a whole, but first broken down into separate blocks:

Each block represents a separate microcircuit or board.

The signal from the device under test is supplied through the Y input to the input divider, which sets the sensitivity of the measuring circuit. After passing preamp and the delay line it goes to the final amplifier, which controls the vertical deflection of the indicator beam. The higher the signal level, the more the beam is deflected. This is how the vertical deflection channel is designed.

The second channel is horizontal deflection, needed to synchronize the beam with the signal. It allows you to keep the beam in the place specified by the settings.

Without synchronization, the beam will float off the screen.

There are three types of synchronization: from external source, from the network and from the signal under study. If the signal has a constant frequency, then it is better to use synchronization from it. The external source is usually a laboratory signal generator. Instead, a smartphone with a special application installed on it is suitable for these purposes, which modulates the pulse signal and outputs it to the headphone jack.

Oscilloscopes are used in repair, design and configuration of various electronic devices. This includes car system diagnostics, troubleshooting V household appliances and much more.

The oscilloscope measures:

Signal level.
Its shape.
Pulse rise rate.
Amplitude.

It also allows you to sweep a signal down to thousandths of a second and view it in great detail.

Most oscilloscopes have a built-in frequency counter.

Oscilloscope connected via USB

There are many options for making homemade USB oscilloscopes, but not all of them are accessible to beginners. The simplest option would be to assemble it from ready-made components. They are sold in radio stores. A cheaper option would be to buy these radio components in Chinese online stores, but you need to remember that components purchased in China may arrive in faulty condition, and money for them is not always returned. After assembly, you should get a small set-top box that connects to a PC.

This version of the oscilloscope has the highest accuracy. If the problem arises of which oscilloscope to choose for repairing laptops and other complex equipment, it is better to opt for it.

For production you will need:

Board with separated tracks.
Processor CY7C68013A.
AD9288−40BRSZ analog-to-digital converter chip.
Capacitors, resistors, chokes and transistors. The values of these elements are indicated on the circuit diagram.
Soldering gun for sealing SMD components.
Wire in varnish insulation with a cross-section of 0.1 mm².
Toroidal core for winding a transformer.
A piece of fiberglass.
Soldering iron with a grounded tip.
Solder.
Flux.
Solder paste.
Memory chip EEPROM flash 24LC64.
Frame.
USB connector.
Socket for connecting probes.
Relay TX-4.5 or other, with a control voltage of no more than 3.3 V.
2 AD8065 operational amplifiers.
DC-DC converter.

You need to collect according to this scheme:

Usually, radio amateurs use the etching method to make printed circuit boards. But to make it double-sided this way printed circuit board With complex wiring you won’t be able to do it yourself, so you need to order it in advance from a factory that produces such boards.

To do this, you need to send a drawing of the board to the factory, according to which it will be manufactured. The same factory makes boards of different quality. It depends on the options selected when placing your order.

In order to get a good payment in the end, you need to indicate in the order the following conditions:

The thickness of fiberglass is at least 1.5 mm.
The thickness of copper foil is at least 1 OZ.
Through metallization of holes.
Tinning of contact pads with lead-containing solder.

After receiving finished board Once you have purchased all the radio components, you can begin assembling the oscilloscope.

The first to assemble is a DC-DC converter that produces voltages of +5 and -5 volts.

It needs to be assembled on a separate board and connected to the main one. using shielded cable.

Solder the microcircuits to the main board carefully, without overheating them. The temperature of the soldering iron should not be higher than three hundred degrees, otherwise the soldered parts will fail.

After installing all components, assemble the device into a suitable-sized housing and connect it to computer USB cable. Close jumper JP1.

You need to install and launch the Cypress Suite program on your PC, go to the EZ Console tab and click on LG EEPROM. In the window that appears, select the firmware file and press Enter. Wait for the message Done to appear, indicating the successful completion of the process. If the message Error appears instead, it means that an error occurred at some stage. You need to restart the flasher and try again.

After flashing the firmware, your self-made digital oscilloscope will be completely ready for use.

Self-powered option

At home, radio amateurs usually use stationary devices. But sometimes a situation arises when you need to repair something located far from home. In this case, you will need a portable, self-powered oscilloscope.

Before starting assembly, prepare the following components:

Unnecessary bluetooth headphones or audio module.
Android tablet or smartphone.
Lithium-ion battery size 18650.
Holder for him.
Charge controller.
Jack 2.1 x 5.5 mm.
Connector for connecting test leads.
The probes themselves.
Switch.
Plastic shoe sponge box.
Shielded wire with a cross section of 0.1 mm².
Tact button.
Hot melt adhesive.

You need to disassemble the wireless headset and remove the control board from it. Unsolder the microphone, power button and battery from it. Set the board aside.

Instead of Bluetooth headphones, you can use a Bluetooth audio module.

Use a knife to scrape off the remaining sponge from the box and clean it well using detergents. Wait until it dries and cut out holes for the button, switch and connectors.

Solder the wires to the sockets, holder, button and switch. Place them in place and secure with hot glue.

The wires must be connected as follows shown in the diagram:

Explanation of symbols:

Holder.
Switch.
Contacts “BAT + and “BAT -”.
Charge controller.
Contacts “IN + and “IN -”.
Jack 2.1 x 5.5 mm connector.
Contacts “OUT+ and “OUT -”.
Battery contacts.
Control board.
Power button contacts.
Tact button.
Probe socket.
Microphone contacts.

Then download the virtual oscilloscope application from the play market and install it on your smartphone. Turn on the Bluetooth module and synchronize it with your smartphone. Connect the probes to the oscilloscope and open its software on your phone.

When you touch the signal source with the probes, a curve showing the signal level will appear on the screen of your Android device. If it doesn't appear, it means a mistake was made somewhere.

You should check the correct connection and serviceability of the internal components. If everything is ok, you need to try to start the oscilloscope again.

Installation in the monitor case

This version of a homemade oscilloscope is easily installed in the housing of a desktop LCD monitor. This solution allows you to save some space on your desktop.

For assembly you will need:

Computer LCD monitor.
DC-DC inverter.
Motherboard from a phone or tablet with HDMI output.
USB connector.
A piece of HDMI cable.
Wire with a cross section of 0.1 mm².
Tact button.
1 kOhm resistor.
Double sided tape.

Every radio amateur can build an oscilloscope into a monitor with his own hands. First you need to remove it from the monitor back cover and find a place to install motherboard. Once you have decided on the location, next to it you need to cut holes in the case for the button and USB connector.

The second end of the cable must be soldered to the board from the tablet. Before soldering each wire, test it with a multimeter. This will help you avoid confusing the order in which they are connected.

Next step you need to unsolder the power button from the tablet board and micro USB connector To the tact button and USB socket solder the wires and secure them in the cut holes.

Then connect all the wires as shown in the figure and solder them:

Place a jumper between the GND and ID contacts in the micro USB connector. This is needed for translation USB port to OTG mode.

You need to glue the inverter and the motherboard from the tablet with double-sided tape, and then snap the monitor cover.

Connect to USB port mouse and press the power button. While the device is booting up, turn on the Bluetooth transmitter. Then you need synchronize it with the receiver. You can open the oscilloscope application and verify the functionality of the assembled device.

Instead of a monitor, an old LCD TV that does not have a Smart TV is also perfect. The tablet's hardware surpasses many Smart TV systems in its capabilities. You should not limit its use to just an oscilloscope.

Manufacturing from an audio card

An oscilloscope assembled from an external audio adapter will cost only 1.5-2 dollars and will take a minimum of time to manufacture. In size it will be no larger than a regular flash drive, and in terms of functionality it will not be inferior to its larger brother.

Required parts:

USB audio adapter.
120 kOhm resistor.
Mini Jack 3.5 mm plug.
Test leads.

You need to disassemble the audio adapter; to do this, you need to pry the housing halves open and separate them.

Remove capacitor C6 and solder a resistor in its place. Then install the board back into the case and reassemble it.

You should cut off the standard plug from the probes and solder a mini-jack in its place. Connect the probes to the audio input of the audio adapter.

Then you need to download the corresponding archive and unpack it. Insert the card into the USB connector.

The simplest thing left is to go to Device Manager and in the “Audio, game and video devices” tab, find the connected USB audio adapter. Right-click on it and select “Update Driver”.

Then move the files miniscope.exe, miniscope.ini and miniscope.log from the archive to a separate folder. Run "miniscope.exe".

Before use, the program must be configured. The necessary settings are shown in the screenshots:

If you touch the signal source with the probes, a curve should appear in the oscilloscope window:

So to turn audio adapter for oscilloscope, you need to put in a minimum of effort. But it is worth remembering that the error of such an oscilloscope is 1-3%, which is clearly not enough to work with complex electronics. It is perfect for a beginner radio amateur, but craftsmen and engineers should take a closer look at other, more accurate oscilloscopes.

An oscilloscope is a very important instrument that is used in radio engineering laboratories involved in the manufacture and testing of many devices. But they can also be used in ordinary radio workshops. The main task of devices of this type is to detect and correct electronic circuits, debugging their operation, and most importantly, avoiding problems in the manufacture of new circuits.

A significant drawback of oscilloscopes is their fairly high price. Therefore, not everyone can buy them. That's why the question arises, ? Although there are many known options for such manufacturing, each method involves one main element - a PC sound card. An adapter is attached to it, thanks to which the levels of the measured signals are coordinated.

Software

This device works thanks to a specific program. It transmits signals to the screen that are visualized. In this way, the measured pulses are converted. The choice of utilities is quite large, but not all of them can work consistently well.

The proven Osci program has gained the most popularity. Thanks to it, the oscilloscope works in normal mode. The program has an interface; a grid is installed on the screen, thanks to which you can measure the signal in length and amplitude. This mesh is special because it provides additional functions. By choosing this program, there are a number of positive aspects that other programs cannot guarantee.

Technical data

To build an oscilloscope from a computer, you need to assemble a so-called voltage divider or attenuator. This device allows you to cover a wide range of measured voltages and protect the input port of the sound card from damage. Damage of this level occurs mainly due to high voltage.

Almost all audio cards have an input voltage of no more than 2 volts. An oscilloscope made from a computer is limited in the capabilities of the sound card. If we consider budget cards, then for them this figure remains at the level of 0.1 Hz - 20 kHz.

The voltage at its lower point is 1 mV. Such a low figure is explained by the limitation of background and noise levels. Upper voltage parameters – up to 500 volts. It is limited by the adapter parameters.

Advantages and disadvantages of oscilloscopes

No radio amateur can do without an oscilloscope. Although this device is sold at a fairly high price. But at the same time, it has both advantages and a number of disadvantages.

The main advantage of an oscilloscope created with your own hands from a computer is its low price. That is, you will have to spend very little money on its re-equipment. But there are several disadvantages:
1. High sensitivity. The device responds to even low-level interference. This leads to large errors.
2. Amplitude sound signal up to 2V. The sound card input is not able to withstand more. Therefore, the sound card can fail quite quickly. However, this can be avoided.
3. Failure to continuously measure voltage. This, in fact, is not a significant drawback.

Creating an Oscilloscope

Since some oscilloscopes do not allow a signal higher than 2V, and for some it does not exceed 1V, you need to try to eliminate this problem, since such an amplitude is clearly not enough. The solution to the problem lies in increasing the limits that the adapter can handle. A modern program that ensures the operation of an oscilloscope allows one to achieve such measurement limits - 12.5 and 250 Volts.

If a signal whose amplitude is 250 Volts is not needed, then you can make an adapter with two channels. To do this, a protection is installed that controls the operation of the device, that is, it does not allow erroneous switching on if the voltage is quite high.

To reduce the influence of external noise on the oscilloscope from the computer, it is necessary to place the board in a housing made of metal. Afterwards, a common wire is connected to this housing.

The process of setting up the sound card is accompanied by turning off the microphone gain. To do this, the volume on it is set to average or below average. Once all the work is done, you can start measuring the secondary processing pulses of the transformer. If everything is done correctly, then it will be able to display oscillograms of even the most low frequencies. Thanks to installed program it will be possible to easily determine the signal frequency level.

It’s quite easy to make a modern device from a computer. The oscilloscope will produce waveforms that will help in work and experiments carried out in radio engineering and home laboratories.

Today, often instead of making, for example, an oscilloscope from a computer, most people prefer to simply purchase a USB oscilloscope. But after shopping, you can see that the price of budget oscilloscopes starts at $200. And serious equipment costs many times more. It is for those people who are not satisfied with this price that the easiest way is to make an oscilloscope from a laptop or computer with your own hands.

What to use

The most optimal today is Osci program, it has an interface similar to a classic oscilloscope: on the monitor there is a standard grid with which you can measure the amplitude or duration yourself.

One of the disadvantages of this program is that it works a little unstable. During operation, the utility may sometimes freeze, and in order to reset it later, you need to use a specialized TaskManager. But all this is compensated by the fact that the program has a familiar interface and is quite easy to use, and also has a large number of functions, they make it possible to make a fully functioning oscilloscope from a computer or laptop.

On a note

It must be said that the package of these programs includes special low frequency generator, but its use is undesirable; it tries to completely control the operation of the sound card driver itself, which causes the sound to turn off. If you decide to try it, make sure you have a restore point or make a backup of your OS. The best way to make an oscilloscope from a computer with your own hands is to download a working generator.

"Vanguard"

This is a domestic program, it does not have the usual and standard measuring grid, and is very different big screen for taking screenshots, but at the same time allows you to use the installed frequency meter and voltmeter amplitude values. This partially compensates for the disadvantages mentioned above.

Having made this oscilloscope from a computer, you will encounter the following: at low levels of indicators, a voltmeter and frequency meter can significantly distort the data, but for beginner radio amateurs, this utility will be quite sufficient. One more useful function It will be that you can do absolutely independent calibration of the two existing scales of the installed voltmeter.

How to use it

Due to the fact that the input circuits of the sound card have a special isolation capacitor, the computer in the role of an oscilloscope can work only with a closed entrance. Thus, only the variable component of the indicators will be visible on the monitor, but with some skill, using these programs you can measure the indicator with a constant component. This is very important in the case when, for example, the counting time of a multimeter does not make it possible to record a certain value of the voltage amplitude on a capacitor charged using a large resistor.

The lower voltage value is limited by background and noise levels and is approximately 1 mV. The upper limit is limited only by the indicators of the divider and reaches more than a hundred volts. The frequency range is limited by the sound card itself and for older computers is about 20 kHz.

Naturally, in this case a rather primitive device is considered. But when you do not have the opportunity, for example, to use a USB oscilloscope, then in this case its use is quite acceptable. This device will help you in repairing various audio equipment, or can be used for educational purposes. In addition, the oscilloscope program will allow you to save the plot to illustrate the material or for posting on the network.

Electrical diagram

If you need an attachment to your computer, then making an oscilloscope will be much more difficult. Today on the Internet you can find quite a large number of different circuits for these devices, and to make, for example, a two-channel oscilloscope, you will only need to duplicate them. The second channel is often relevant when it is necessary to compare two signals or an oscilloscope is used to connect external synchronization.

As a rule, the circuits are very simple, but this way, you will independently provide a very large range of available measurements using a minimum of radio components. Moreover, an attenuator, which is made according to the classical scheme, would require you to have highly specialized high-ohm resistors, and its input resistance changed all the time when switching the range. Therefore, you would experience some limitations when using conventional oscilloscope leads, which are rated for input impedances of no more than 1 mOhm.

How to choose voltage divider resistors

Due to the fact that radio amateurs often have difficulty selecting precision resistors, it often happens that they have to choose wide-profile devices that need fit as accurately as possible, otherwise you won’t be able to make an oscilloscope from a computer with your own hands.

Voltage divider trimmer resistors

In this case, each arm of the divider has two resistors, one is constant, the second is tuning. The disadvantage of this option is its bulkiness, but the accuracy is limited only by what available characteristics the measuring apparatus has.

How to choose regular resistors

Another option to make an oscilloscope from a computer is to select pairs of resistors. Accuracy in this case is ensured due to the fact that pairs of two sets with a fairly decent spread are used. It is important to initially carry out careful measurements of all devices, and then select pairs whose total resistance will be most suitable for your circuit.

Today, adjusting resistors by removing part of the film is often used even in modern industry, that is, an oscilloscope is often made from a computer.

But it must be said that if you want to customize high-resistance resistors, then the resistive film should not be cut all the way through. Since in these devices it is located on a cylindrical surface in the form of a spiral, therefore the undercut must be made extremely carefully so that prevent the chain from breaking. Then:

After, when the resistor is completely adjusted, place of cut covered with a layer of special protective varnish.

Today this method is the fastest and simplest, but at the same time it gives good results, which made it optimal for home use.

Things to consider

There are a number of rules that must be followed in any case if you decide to carry out this work:

The computer used for the oscilloscope must be grounded.
Do not connect the ground to the outlet. It is connected through a special line input connector housing with the housing system unit. In this case, no matter whether you hit phase or zero, you will not have a short circuit.

In other words, only a wire that can be connected to a socket is connects to resistor, and is located in an adapter circuit with a nominal value of one megohm. If you try to connect a wire that is in contact with the housing into the network, then in almost all cases this will certainly lead to the most disastrous consequences.