MAXIMUM voltage without a divider is 100V.

Miniature oscilloscope probe Chameleon D2

Brief specifications: — bandwidth: 0…1 MHz; - sensitivity: 50 mV / div ... 10 V / div; — sweep speed: 0.5 µs/div…0.1 s/div; - maximum sampling rate: 5 MHz; — start sweep on the front or on the fall: auto, single or external signal. Scheme:

User's Manual The power is turned on by long (1 sec) pressing the middle button. If the button is held down while turning on "DOWN", then the service menu is called to adjust the color, brightness and tone of the sound signal. A short press of the middle button causes a transition to the operating mode with saving the changed settings. If the "UP" button is held down when turned on, then the default settings (as they say "factory" ones) are returned. In the operating mode, moving along the menu bar is done using the buttons "LEFT"/"RIGHT", change the selected parameter - with the buttons "UP DOWN "(except in sync selection mode, in which the DOWN button is used to capture the sync in standby mode). Simultaneously pressing the buttons "Up and down" in the sensitivity item, the automatic sensitivity switching mode is switched on. Cancellation - by manually changing the sensitivity using the UP or DOWN buttons. Simultaneously pressing the buttons "Up and down" in the sweep speed item, the automatic speed switching mode is switched on in the range 10 ms/div…0.5 µs/div. Cancellation - by changing the speed manually using the "UP" or "DOWN" buttons. In automatic mode, the sign "*" is displayed in front of the readings. By simultaneously pressing the "UP" and "DOWN" buttons at the beam shift point, the beam is set to the position stored in the memory before the last shutdown; With a short press of the middle button, the transition to the signal analysis mode occurs, where the start and end markers are selected with the “DOWN” button, the markers are moved using the buttons "LEFT"\"RIGHT". The analysis mode is exited by pressing the middle button. Automatic dimming of the backlight (approximately 30 seconds after the last button press) is performed: - in the service menu; — in the analysis menu, if external power is not connected; - in operating mode, if there is no signal for more than 30 seconds (beam line in the middle of the screen) and external power is not connected. Automatic power off (after about 15 minutes): — in the service menu, if external power is not connected or if the battery is connected and charging is completed; — after the backlight is turned off in other modes, if external power is not connected. When an external power supply (5V) is connected, the battery charging mode is activated - the green battery icon changes color to red. After charging the battery to a voltage of 4.15 V, the charging process stops and the battery icon changes to the power plug icon - the battery is disconnected and power is supplied from an external source (5V). The power is turned off by long (1-2 seconds) pressing the middle button. Here's what I got: Photo

Contact name: Denis

Selling! Indispensable in working with auto electrics.
Device characteristics:
The maximum measured frequency is 1 MHz,
- Limits 0.5µs, 1µs, 2µs, 5µs, 10µs, 20µs, 50µs, 100µs, 200µs, 500µs, 1ms, 2ms, 5ms, 10ms, 20ms, 50ms, 100ms, maximum sampling rate: 5MHz.
1. The minimum measured voltage is 50mV / div,
- limits 50mV/div, 100mV/div, 200mV/div, 500mV/div, 1v/div, 2v/div, 5v/div, 10v/div. (with probe 1:10 to 500v).
2. Trigger sweep on edge or trailing edge: auto, single or external
signal.
4. Power supply 3.7V, Li-Ion battery from mobile phone.
5. Active window for waveform 120*176 points, LCD LS020.
6. Charging the battery through the miniUSB connector from the adapter with Uout = 5.0v.
In addition, the following service functions have been added:
Automatic dimming of the backlight (approximately 30 seconds after the last button press) is performed:
- in the service menu;
- in the analysis menu;
- in operating mode, if there is no signal for more than 30 seconds.
Auto power off (after about 15 minutes):
- in the service menu, if external power is not connected or if battery charging is connected and completed;
- after extinguishing the backlight in other modes.
When an external power supply (5V) is connected, the battery charging mode is activated - the green battery icon changes color to red.
After charging the battery to a voltage of 4.15 V, the charging process stops and the battery icon changes to the power plug icon
- the battery is disconnected and the power is supplied from an external source (5V).
The kit includes customized board + case.

I will develop and assemble any electronic devices under the order.

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

Today, devices for taking the main frequency, amplitude characteristics and waveforms are convenient, portable and more compact devices. Often they are performed as a separate set-top box that connects to a computer. This maneuver allows you to remove the monitor from the package, significantly reducing the cost of equipment.

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

How can I get an oscilloscope

Equipment can be obtained in several ways and it all depends solely on the size Money, which can be spent on the purchase of equipment or parts.

• Buy a ready-made device in a specialized store or order it online;
• To buy a constructor, for example, sets of radio components, cases, which are sold on Chinese sites, are now very popular;
• Independently assemble a full-fledged portable device;
• Mount only the prefix and probe, and organize the connection to a personal computer.

These options are listed in order of decreasing equipment cost. Buying a ready-made oscilloscope will cost the most, since it is 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 simple do-it-yourself oscilloscope circuit, and the price is reduced by paying only the cost of radio components. In this category, it is also necessary to distinguish between more expensive and simple models in terms of configuration and functionality.

Assembling the device yourself according to the available schemes and radio components purchased at different points may not always be cheaper than acquiring a designer, therefore, it is necessary to first evaluate the cost of the idea, its justification.

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

Oscilloscope Builder: Model DSO138

Chinese manufacturers have always been famous for their ability to create electronics for professional needs with very limited functionality and for quite a bit of money.

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

One of the most popular Chinese-made models such as an oscilloscope designer is 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 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 the necessary radio components, assembly instructions and a circuit diagram.

It facilitates the work of the presence of appropriate markings on almost all parts and the board itself, which really turns the process into assembling children's constructor adults. On the diagrams and instructions, all the necessary data is clearly visible and you can figure it out without even 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 10 mV/div - 5V/Div (1 - 2 - 5);
• Discrete frequency: 1 Msps;
• Input resistance: 1 MΩ;
• Time Interval: 10us / Div - 50s / Div (1 - 2 - 5);
• Measurement accuracy: 12 bits.

Step-by-step instructions for assembling the DSO138 constructor

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 should be noted that in this model the board comes with a soldered 32-bit Cortex™ microcontroller on the M3 core. It works with 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 mounted makes the task somewhat easier.

Step 1. It is most convenient to start the installation with smd components. It is necessary to take into account the rules when working with a soldering iron and a board: do not overheat, hold no longer than 2 s, do not close 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 place allotted for it on the board, cut off the excess leg length 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 side of the diodes and transistors. Quartz has a metal in its structure, so you need to ensure that its surface does not directly contact the tracks of the board or take care of the dielectric lining.

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

Step 5. Dry the board and check how well the soldering was carried out. Before connecting the shield, you need to solder two jumpers to the board. The existing bitten-off conclusions of the parts will be useful in this.

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

The check consists in taking indicators from:

• Connector 9 V;
• Reference point 3.3 V.

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

Step 7. Insert the display into the 3 available connectors. You need to connect the probe for the oscilloscope to the input, turn on the power with your own hands.

result correct installation and assembly will be the appearance on the display of its number, type of firmware, its version and the developer's website. After a few seconds it will be possible to observe the sine waves and the scale with the probe turned off.

Computer prefix

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

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

Having placed the assembled device with ready-made outputs in it, you can begin to organize 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, the program will reflect the changes. Such a set-top box is connected to a microphone or line input and does not require any additional drivers.

DIY oscilloscope photo

In this article, I want to tell you about my experience in making the Chameleon oscilloscope probe, which is wonderful and popular with radio amateurs. The network has a lot of information on it, but still I will tell you in detail about my Chameleon.

So, it was decided to purchase the board, since it is double-sided and in some places the tracks are quite small, so making it at home is problematic (although possible). Another difficulty is the display. Since, in the Chameleon, the display from the Siemens CX65 phone is used, which was discontinued a long time ago. That is why manufacturing should begin first of all with a search for a display. Siemens CX65 phones used 3 types of display, on the LS020, LPH8836 controller, and one more type that is in no way suitable for the Chameleon. The most preferred first type of display (LS020), the second (LPH8836) can also be used by flashing the controller with the appropriate firmware, but the speed of working with this type of display is slower.

Details for the Chameleon it is better to buy everything at once. If you buy a board, then often sellers offer accessories for it. It is much faster and more convenient, and purchasing separately is another headache. Installation is better to start with resistors and capacitors, then solder zener diodes, transistors and microcircuits. If your board is not factory-made, but self-made, you will have to recalculate the input circuits. This process is described in detail in the instructions that are in the archive along with the firmware and the board. The greatest difficulty in the Chameleon is the installation of the processor (Atmega32), and the ADC (AD9280). The pin pitch is quite small, especially in the ADC, so you need to be careful when installing. Another detail worth paying attention to: tantalum capacitors are used in the design, and their “plus” is on the side where the strip is. If the polarity is reversed, the device will not work. I advise you not to solder R9-R11, R19, R14-R18 before flashing (These resistors sometimes interfere with firmware), well, do not solder the L1 choke. Be sure to put a gasket under the quartz; you can cut it out of ordinary cardboard. You can flash the MK with any programmer, which is full on the network. It is flashed in-circuit, for this you need to solder the corresponding conclusions of the programmer to the pads on the circuit. We connect the programmer, select the desired hex-file and flash it. After a successful firmware, we switch to fuses, carefully look at which ones to put in, which ones to remove and program them.

After the firmware, we solder the missing resistors, solder the display, do not solder the throttle yet, apply power, 3.7V to the battery connection contacts and hold down the central button. In this case, the device should start up on the screen, an image will appear, although it is visible only when light falls on the screen, since the backlight choke is not installed. After we turn off the device, install the L1 throttle, and try to turn it on again, while the screen backlight should start. Often, when you first turn on the beam goes up, you can return it to its place with the arrows “up”, “down” in the operating mode of the device. You can check the correctness of the settings using a regular battery. We select the DC mode, connect the battery to the probes, look at the beam deflection up, then connect the battery with reverse polarity and look at the beam deflection down. Both up and down the beam should deviate equally. To measure the deviation (voltage), you can in the scanning mode, press the center key, then the button down, the first marker will appear, then down again - the second marker will appear, and in the upper right corner the voltage value. The duration and frequency are also displayed there. If you turn on the device with the down button pressed at the same time, you go into the settings mode. Here you can set the color of the background, grid, beam, etc. Also here you can set the tone of the sound signal and control the voltage value on the battery. If you have not worked with an oscilloscope before, I advise you to read a little about its modes and functions, this will make it easier to work with Chameleon.

And finally, the most interesting thing remains - to place the board in the case. The dimensions of my case are 92*50*25mm. Grooves for the board are cut in the side walls and it lies perfectly there. The display is fixed with silicone to the front panel. The battery is attached to the bottom with double-sided tape. It turned out to be a small compact device. The only difference is that in the author's version the control buttons are on the left, I have them on the right (I just changed the assignment of the buttons up and down and left and right in places, cut the tracks and then connected them with conductors). Desoldering the probe is easy: if we look at the mini-jack, then the thickest one is a minus, the middle one is a signal. The last one is the external synchronization input, rarely used.

Well, that's all. I wish you all a successful build. Well, a photo of my beast 8-)

MAXIMUM voltage without divider -100V.

Miniature oscilloscope probe Chameleon D2

Brief specifications:

— bandwidth: 0…1 MHz;
- sensitivity: 50 mV / div ... 10 V / div;
— sweep speed: 0.5 µs/div…0.1 s/div;
- maximum sampling rate: 5 MHz;
— start sweep on the front or on the fall: auto, single or external signal.

Well, here it is ready best option variant of the Chameleon. I want to express my gratitude to comrade y_kiyko for his help in creating the iron part of the oscilloscope. It moved rarely used menus to the service. Added vertical movement of the beam, increased
input resistance up to 1mΩ. And also switching on and off with a button without fixing.

Thanks to darian for help in testing firmware with no brake on long sweeps that interfere with button control. This firmware is adapted for
option from y_kiyko.

About the device.
- added automatic sensitivity switching (activation - by simultaneously pressing the UP and DOWN buttons in the sensitivity item, deactivation - by manually changing the sensitivity using the UP or DOWN buttons). In the automaton, the “*” sign is displayed before the sensitivity value (the idea is taken from http://Oscilloscop-dss31.narod2.ru);
— added automatic switching of the sweep speed for 0.5µs/div…10ms/div (activation — by simultaneously pressing the UP and DOWN buttons in the sweep speed item, deactivation — by manually changing the speed with the UP or DOWN buttons). In the machine, before the sweep speed value, the “*” sign is displayed;
- by simultaneously pressing the UP and DOWN buttons at the beam shift point, the setting is added to the position stored in memory before the last shutdown (the idea is again from http://Oscilloscop-dss31.narod2.ru).
I would like to note the features of automatic switching of the sweep speed.
Because in Chameleon, there is only one sample per displayed point, with some combinations of signal frequency and sweep speed, a stroboscopic effect occurs, leading to incorrect readings (lowering the frequency of the displayed signal or, as it were, “stretching” the waveform horizontally). This effect is very sensibly described on the aforementioned site http://Oscilloscop-dss31.narod2.ru (bravo to the author!). So it has been noticed that the wrong sweep speed is sometimes set in the machine, while the signal trembles somewhat or the sweep switches continuously from one limit to another, and the signal is stretched at one limit, and strongly compressed at the other. In such cases, press the UP and DOWN buttons at the same time in the sweep speed item. In this case, the adjustment starts with the highest sweep speed of 0.5 µs/div. As the speed decreases, the signal is usually captured correctly.

Any diodes D4, D6-D8, D13 (TL431) smd can be with different pinouts (check with LH). LDO stabilizers can be any, also check with LH. Battery measurement resistors R25, R26 must be selected with the same rating. Resistors and capacitors of the input divider are composite of two cases, do not select very precisely, the ratings are calculated. Stereo mini-jack input connector is standard. The buzzer is a flat piezo tablet with a soldered tap, soldered onto a board with a small gap. We solder the quartz body to the ground. The cable to the display is flat with the desired pitch (boards are connected in office equipment) bends 180 degrees under the display. The solid-state relay used the easiest and cheapest one. Backlight inductor conventional or chip. Minus 3v is adjusted by selecting one of R4. The height of the buttons depends on the selected case design. And finally, so that the flux does not flow where it is not supposed to, you need to solder the buttons and connectors after washing the board.

We turn on the long (3-4 seconds) by pressing the middle button.
When turned on, holding down the "down" button, we get into the service menu, where you can adjust the colors, brightness and tone of the sound signal.

Once again, press the middle button, go to the operating mode with saving the changed settings.

In the operating mode, move along the menu bar with the “left”\”right” buttons, change the selected parameter with the “up”\”down” buttons (except for the synchronization selection mode, in which the “down” button serves to capture synchronization in standby mode).
When turned on, holding the "up" button returns to the default settings.
A short press of the middle button leads to the signal analysis mode, where the “down” button selects the start and end markers, move the markers with the “left”\”right buttons

Do-it-yourself probe with a divider for the Chameleon

To make it, we need:

- an ordinary probe from a Chinese multimeter,

- 0.5 meters of some thin coaxial microwave cable,

- 3.5mm stereo mini-jack

- micro switch

- a thin contact pin from some kind of scoop connector,

- pieces of heat shrink tubing of different diameters,

- “loose”, several MLT-0.125 2MOhm resistors, smd capacitors of size 1206 with denominations of one to tens of picofarads.

As well as a soldering iron, a scalpel, tweezers, pliers, wire cutters, a tester with the ability to measure capacitances from units of picofarads and resistances up to 10MΩ, a pair of not very crooked hands and an uncontrollable desire to “stir up” something.

And so, let's get started! To begin with, we need to choose the very suitable microwave cable. How to pick it up? First of all, from the available ones, we select visually according to a suitable diameter for our probe. Further along the cross section of the central core - the thinner it is, the better. And last but not least, in terms of capacity between the central core and the braid, again, the smaller the better. I found in my stocks a piece of such a cable from some soviet microwave device.

The capacitance of a 0.5 meter piece was about 30pF. Better, I think, may be the parameters of the cables of external car GSM antennas (often found in the "junctions" of radio markets). Ideal parameters for cables of high-frequency probes of oscilloscopes. There, the central vein generally happens in the form of the finest steel hair. Electrical and wave resistance, as well as other parameters of the cable in this case, are of little interest to us. Immediately solder JACK 3.5mm, because for further actions we will need to connect the cable to the oscilloscope.

Now let's prepare the probe itself. Using pliers, carefully pull the pin out of it, heat it up with a soldering iron and very carefully remove the plastic cylinder (it will come in handy for us). Next, cut out a rectangular hole for the microswitch. It should turn out like this:

We drill a hole on the side through which we pass the "earth" wire:

Now let's deal with the actual divider. The Chameleon "D" version has an input impedance of 510 kOhm. To implement a voltage divider by 10, we need to increase this resistance by a factor of 10 510kΩ*10=5.1MΩ. We already have 510 kΩ inside the oscilloscope itself, so we need 5.1 MΩ-510 kΩ = 4.59 MΩ in the probe.

For resistance to high input voltage, this resistance is best made up of two of approximately 2.295 MΩ each. Where can I get resistors with such a fancy value? Be patient, we will make them ourselves. More precisely, we are modernizing the existing MLT0.125 with a nominal value of 2MΩ. We wind the leads of the resistor onto the probes of the multimeter, turn on the multimeter in the resistance measurement mode and, slowly, very carefully, we begin to scrape off the enamel with a scalpel, then the resistive layer, all the while monitoring the readings of the multimeter. We finish the process when the resistance value becomes equal to 2.29-2.3 megaohms.

We will adjust the second resistor using a slightly different method. We solder it in series with the fitted one and to the input of the oscilloscope. We apply a constant voltage directly to the input of the oscilloscope, note the readings. Next, we set the sensitivity to 10 times more and apply the same voltage through the resistors (I used a stabilized 9V source for this). Now, just as slowly and gently with a scalpel, we begin to scrape the second resistor. We finish the process when the beam drops to our mark.

If we “overdid it” with scraping, we take a “fresh” resistor and start scraping again. At first I tried to rub with abrasive paper “zero” and ruined two resistors, so I strongly recommend scraping only with a scalpel - this way the process proceeds more slowly and in a controlled manner.

We figured out the constant voltage divider. Now let's proceed to the selection of the reactive component of the divider and compensation for the influence of the cable capacitance. To do this, we need a SPECIAL FORM SIGNAL GENERATOR. Scary? Nothing, I don’t have it either, but our Chameleon has a pulse converter, which, by the way, will give us the desired signal reverse side Chameleon boards to the pad that is common to the inductor, Schottky diode and drain field effect transistor. We turn on the Chameleon and fix the signal range.

We set the voltage sensitivity ten times greater, solder a 4-30pF tuning capacitor in parallel with the resistors and solder the cable input to our “locomotive”. Be sure to let the chain cool down before starting the adjustment, since the capacitance of ceramic capacitors is related to the temperature by the so-called TKE (temperature coefficient of capacitance), so we must perform all manipulations with capacitors only after letting them cool down. Gently rotating the capacitor disk, we achieve readings with the same scope.

We unsolder the capacitor, let it cool down to room temperature and measure the capacitance. We multiply it by two, since we will compose it from two capacitors connected in series. I got 11-12pF, so I took two 22pF capacitors. Now, with a scalpel, we carefully clean the enamel from the output cups of the resistors, tin and solder the capacitors to them.

Let's check what happened.

Ches-word valerian did not drink! But either he didn’t let the trimmer cool down, or he multiplied 2x2 incorrectly, in the end he missed a lot. I unsoldered the capacitors and set them to 12pF each, then after the next measurement I added another 3pF to them in parallel.

We perform a control check of our divider. First, we fix the signal range without an additional chain,

then we set ten times the sensitivity and check with the connected chain

Happened!

Let's start assembling our probe. We string heat shrink wires on the wires, strip the wires (I used MGTF) and carry out all soldering. We thoroughly wash our chain and soldering points with alcohol-gasoline or acetone, cover with electrostrong nitro-lacquer (I recommend zapon-lacquer, but in the absence of such, I covered it with a transparent manicure).

Let the varnish dry and recoat. After drying, we continue the assembly. We pass the wires into the probe and take them out of the necessary holes, seat the heat shrink on the cable and carefully “tighten” our structure inside the probe body. All unshielded wires should be as short as possible so as not to catch unnecessary signals and not introduce additional capacitance. We solder the switch very carefully so that the flux and soldering material do not get inside. Wet with a cotton swab in the solvent, remove the remaining flux and carefully varnish the soldering points, making sure that the varnish does not get inside.

We put the switch in the hole prepared for it.

Finally, it came to our plastic cylinder, pulled hot from the native pin. We insert into it our pre-shortened to the desired length and re-sharpened pin-contact. If it is thinner than the hole in the cylinder (as in my case), crimp it with a layer or two of heat shrink so that it fits snugly into the cylinder. Solder and rinse.

We insert the cylinder with the pin into place.

It remains only to put on and crimp the heat shrink on the cable and probe body, and solder the crocodile connector to the ground wire. And… Voila!!!

Here is a diagram of what I got.

In principle, according to the described technology, it is possible to select a divider for almost any measuring device. It should only be remembered that the Z-characteristics given to the probe input will consist of the sum of those of the probe itself and the device to which it is connected. So, the smaller the capacitance of the cable is selected, the smaller the total capacitance will be brought to the probe of the measuring device and the less influence it will introduce into the circuit under study.

http://radiokot.ru/lab/hardwork/59/