Transistor tester: what is it and how to use the device

If you repair or are fond of soldering electronic equipment, then you know that you often have to check parts for serviceability, measure the parameters of resistors, capacitors and inductors, determine the pinout of transistors and other semiconductor elements. To simplify this matter for yourself - pay attention to the universal transistor-tester or, as it is called, the RCL meter.

What it is

The transistor tester is a universal digital measuring device capable of testing not only transistors, but other elements as well. As semiconductor - thyristors, triacs, diodes and others, and passive elements, for example: resistors, capacitors, inductors.

However, in most cases, the above elements are more convenient and faster to check for serviceability. multimeter, but this device will still come in handy as an ESR tester.

ESR is the Equivalent Series Resistance, an important parameter for electrolytic capacitors. Due to the impossibility of measuring it with a household multimeter, and specialized ESR meters are expensive, it is much more difficult for beginners to diagnose faults in electronic circuits.

With the help of transistor testers, you can measure ESR with normal accuracy, and the cost of these devices ranges from $ 10-20, depending on the model.

This device is often called the "Marcus Transistor Tester", which is somewhat incorrect. Initially, the idea to create a universal tool for checking radio components originated with Markus Frejek, later Karl Heinz Kubbeler continued his business. And the so-called transistor testers with aliexpress are nothing more than copies of the Markus tester, devices modified by enthusiasts. In this connection, they do not have a specific manufacturer, but they have a wide community on the Internet. Thanks to this, it is easy to find Russian-language firmware and instructions for upgrading the device.

Types of testers

Various modifications of transistor testers are presented on the electronics market, we will consider popular options.

LCR-T4 or T3 - yellow board and one key, the device is powered by a "crown" battery (9V). Only knows how to check elements with 2 or 3 pins (see the list below). This device has a two-color backlit LCD display with a resolution of 128x64 pixels. There are no obvious differences between T4 and T3, most likely there is some difference in the firmware.

It can be supplied in the form of a kit-set (constructor) for self-assembly, or already in a finished form, most often without a case. Some Aliexpress sellers offer clear acrylic or opaque plastic in white or black. The DIY kit can be supplied with a red board and a microcontroller in a DIP28 package. The cost of the device is from 4 (without case) to 10 (in case) dollars.

TC-1, TC-6, T7 is always supplied in a white case. It features a large number of functions, there is a window for testing IR diodes, as a result of which the code transmitted by the diode is displayed on the display. In this way, the remote controls can be checked. The TC-1 has a color display with a resolution of 160x128 pixels. Control is also carried out by pressing 1 button.

The main feature of TC-1 and its fellows - Power is supplied from the built-in battery, which is charged via the micro-USB connector. The cost of the device is in the range of $ 13-20.

You can see a comparison of the speed and other features of these devices in this video:

GM328 is the most advanced model with encoder and color display, but there are also cheaper two-color display options. It is supplied both on the board and in an acrylic transparent case (or from other materials). Usually it is a black or red board. Power can be supplied either from the "crown" or from the power supply unit through the connector on the board. The control is carried out by the encoder, by turning or pressing which you select the desired menu item. Distinctive features are the presence of a frequency generator, a frequency counter, a PWM signal generator (duty cycle varies from 0 to 99%) and some other useful functions. The cost of the device is in the range of 10-15 dollars.

I repeat that all devices have functions for measuring the parameters of transistors and passive components, with approximately the same accuracy. It depends on the assembly and accuracy of the components in the microcontroller harness. All testers are based on the Atmega328 microcontroller from AVR. At the same time, it makes no sense to list the full functionality and characteristics of each, since there are firmware with a frequency counter and generator and for the simplest model - T4, as well as Russified firmware and the device regularly is being modernized.

How to use

When you turn on the transistor tester for the first time, a calibration and self-test occurs, during which you will need to first close three pins on the ZIF-panel, and then remove the jumper and install a capacitor with a capacity of more than 100 nF. It often comes with the device.

Now let's talk about how to check an electronic component. There is a ZIF-panel for connecting elements. This is a special panel with a lever clamp for connecting electronic components. It is used most often on programmers and, as in our case, on universal component testers.

Despite the fact that there are many connectors in the socket of the transistor-tester, you can see in the photo above that the numbers from 1 to 3 are marked and they are repeated. The connectors are simply closed among themselves, this is necessary for the convenience of connecting elements in different cases.

After connecting the element to the tester, you need to press the button (or the encoder, in the case of using the M328 model). The screen will display a graphic designation of the component, with its pinout and its characteristics (in the case of determining the parameters and serviceability). If the part is faulty, it will give something like "No, unkown, damage part". The measurement takes place with a delay of 1-2 seconds, since the device first performs a self-test.

What measures and determines

The transistor tester is able to determine the parameters and pinout of such semiconductor elements as:

• Two-pin components - diodes, zener diodes, LEDs (shows the voltage at which the glow starts) and some others.
• Triodes - transistors (mosfet - gate capacity and opening voltage, J-fet, bipolar - voltage drop and hFE), thyristors and triacs. It also checks assemblies of Schottky diodes in three-pin TO-220 packages and the like.

Passive components:

• resistors (measures resistance);
• capacitors (capacity, Vloss - voltage drop after a charging pulse, ESR);
• chokes and inductors (inductance, DC resistance).

Models such as GM328a have a built-in PWM signal generator with a pulse frequency of 8 kHz (may also differ in different models), a frequency measurement function up to 2 MHz (while measuring quite accurately frequency of different signals - sinusoid, meander, triangle, saw, there is also information that some versions "measure" up to 3.95 MHz), voltmeter function (up to 50 V and often with large errors). The function of the square wave generator will also be useful - the transistor tester is capable of producing signals with a frequency of up to 2 MHz.

Please note that the lowest frequency - 1 Hz is denoted as 1000 MHz (m - small), that is, "millihertz". This is not a gigahertz!

Nuances

When using, you should remember the nuances and limitations of most transistor testers:

• Powerful thyristors can be recognized as faulty or as transistors.
• Zener diodes. Determines how diodes are. The manufacturer declares normal recognition of elements with a stabilization voltage of less than 4.5V.
• Microcircuits and three-legged integrated stabilizers (7805, 7905 and the like) are not determined or checked.
• Dinistors do not check, because of their high actuation voltage, for example, in the common DB3 it is more than 30 volts.
• Large capacitors are also not recognized, although the manufacturer claims measurement ranges from 30 pF to 100 mF, "adequate" values ​​are issued up to a couple of thousand microfarads.
• Inductance is measured in the range from 0.01 mH to 20 G.
• Ionistors do not recognize.
• Varistors sees as capacitors.
• Unidirectional suppressors are defined as diodes.
• No input protection. This means that you can burn the input if you start measuring a charged capacitor, for example, or if you apply a high voltage. Therefore, discharge the capacitors.

If you want to check a component, but it has short legs, then on the LCR-T4 tester you can make a check by attaching them to the platform under the SMD.

In general, the device has found wide application and will be especially useful for novice radio amateurs when purchasing the first equipment for a home laboratory. If you take into account the cost of the device, then you can put up with all its errors and shortcomings, at least for the sake of convenient function for determining the pinout and determining the ESR of electrolytes when diagnosing sources nutrition.

Now you know what a transistor tester is, how to use it and what this device is intended for. If you have any questions, ask them in the comments below the article!

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