The tester accurately determines the numbers and types of terminals of a transistor, thyristor, diode, etc. It will be very useful for a novice radio amateur.
Types of elements tested
(element name - display indication):
- NPN transistors - "NPN" on display
- PNP transistors- on the display "PNP"
- N-channel-enriched MOSFETs - on display "N-E-MOS"
- P-channel-enriched MOSFETs - on display "P-E-MOS"
- N-channel-depletion MOSFETs - displays "N-D-MOS"
- P-channel-depletion MOSFETs - display "P-D-MOS"
- N-channel JFET - "N-JFET" on display
- P-channel JFET - "P-JFET" on display
- Thyristors - on the display "Tyrystor"
- Triacs - on the "Triak" display
- Diodes - on the display "Diode"
- Double cathode diode assemblies - on the display "Double diode CK"
- Double-anode diode assemblies - on the "Double diode CA" display
- Two diodes connected in series - “2 diode series” on the display
- Symmetrical diodes - on the display "Diode symmetric"
- Resistors - range from 0.5 K to 500K [K]
- Capacitors - range from 0.2nF to 1000uF
When measuring resistance or capacitance, the device does not provide high accuracy
Description of additional measurement parameters:
- H21e (current gain) - range up to 10000
- (1-2-3) - order of connected terminals of the element
- Presence of protection elements - diode - "Diode symbol"
- Forward voltage – Uf
- Opening voltage (for MOSFET) - Vt
- Gate capacitance (for MOSFET) - C=
Device diagram:
Higher resolution diagram.
Microcontroller Programming
If you use the AVRStudio program, it is enough to write 2 configuration bits in the fuse-bit settings: lfuse = 0xc1 and hfuse = 0xd9. If you use other programs, configure the fuse bits in accordance with the picture. The archive contains microcontroller firmware and EEPROM firmware, as well as a printed circuit board layout.
Fuse bits mega8
The measurement process is quite simple: connect the element under test to the connector (1,2,3) and press the "Test" button. The tester will show the measured readings and after 10 seconds. will go into standby mode, this is done to save battery power. The battery is used with a voltage of 9V type "Krona".
Photos of printed tracks:
Triac testing
I would like to share a very useful circuit for every radio amateur, found on the Internet and successfully repeated. This is indeed a very useful device, which has many functions and is assembled on the basis of an inexpensive ATmega8 microcontroller. There are a minimum of parts, so if you have a ready-made programmer, it can be assembled in the evening.
This tester accurately determines the numbers and types of terminals of a transistor, thyristor, diode, etc. It will be very useful for both beginning radio amateurs and professionals.
It is especially indispensable in cases where there are stocks of transistors with half-erased markings, or if you cannot find a datasheet for some rare Chinese transistor. The diagram is in the figure, click to enlarge or download the archive:
Types of tested radioelements
Element name - Display indication:
NPN transistors - "NPN" on display
- PNP transistors - "PNP" on display
- N-channel-enriched MOSFETs - on display "N-E-MOS"
- P-channel-enriched MOSFETs - on display "P-E-MOS"
- N-channel-depletion MOSFETs - displays "N-D-MOS"
- P-channel-depletion MOSFETs - display "P-D-MOS"
- N-channel JFET - "N-JFET" on display
- P-channel JFET - "P-JFET" on display
- Thyristors - on the display "Tyrystor"
- Triacs - on the "Triak" display
- Diodes - on the display "Diode"
- Double cathode diode assemblies - on the display "Double diode CK"
- Double-anode diode assemblies - on the "Double diode CA" display
- Two diodes connected in series - “2 diode series” on the display
- Symmetrical diodes - on the display "Diode symmetric"
- Resistors - range from 0.5 K to 500K [K]
- Capacitors - range from 0.2nF to 1000uF
Description of additional measurement parameters:
H21e (current gain) - range up to 10000
- (1-2-3) - order of connected terminals of the element
- Presence of protection elements - diode - "Diode symbol"
- Forward voltage - Uf
- Opening voltage (for MOSFET) - Vt
- Gate capacitance (for MOSFET) - C=
The list shows an option for displaying information for English firmware. At the time of writing, Russian firmware appeared, with which everything became much clearer. To program the ATmega8 controller, click here.
The design itself is quite compact - about the size of a pack of cigarettes. Powered by a 9V Krona battery. Current consumption 10-20mA.
To make it easier to connect the parts under test, you need to select a suitable universal connector. Or better yet, several - for different types of radio components.
By the way, many radio amateurs often have problems checking field effect transistors, including with an insulated shutter. Having this device, you can find out in a couple of seconds its pinout, performance, junction capacitance, and even the presence of a built-in protective diode.
Planar SMD transistors are also difficult to decipher. And many radio components for surface mounting sometimes cannot be even roughly determined - either a diode or something else...
As for conventional resistors, here too the superiority of our tester over conventional ohmmeters included in DT digital multimeters is evident. Here, automatic switching of the required measurement range is implemented.
This also applies to testing capacitors - picofarads, nanofarads, microfarads. Simply connect the radio component to the device sockets and press the TEST button - all the basic information about the element will immediately be displayed on the screen.
The finished tester can be placed in any small plastic case. The device has been assembled and successfully tested.
Discuss the article TESTER OF SEMICONDUCTOR RADIO ELEMENTS ON A MICROCONTROLLER
AVR transistor tester
AVR-Transistortester construction kit - supplied as a set of parts which includes:
printed circuit board and all parts including resistors and capacitors that are required to assemble a working device. The kit does not include a housing. The device does not require adjustment and is operational immediately after assembly. The processor is installed in the socket. The LED is not displayed on the front panel. It is not an indicator, but is required for the operation of the device. During operation, its glow may not be visible. The display is connected to the main board via a comb with a pitch of 2.54 mm. All documentation necessary for assembling the device ( schematic diagram, wiring diagram and a list of components used) can be downloaded at the end of the article.
The photo shows the finished assembled device. The second photo shows a set of parts.
A construction kit is a collection of parts. The battery is not included.
Device capabilities.
The tester allows you to determine bipolar transistors, MOSFET and JFET field-effect transistors, diodes (including double series and anti-parallel), thyristors, triacs, resistors, capacitors and some of their parameters. In particular for bipolar transistors:
1. conductivity – NPN or PNP;
2. pinout in format – B=*; C=*; E=*;
3. current gain – hFE;
5. forward base-emitter voltage in millivolts - Uf.
For MOSFET transistors:
1. conductivity (P-channel or N-channel) and channel type (E – enriched, D – depleted) – P-E-MOS, P-D-MOS, or N-E-MOS, N-D-MOS;
2. gate capacity – C;
3. pinout in GDS=*** format;
4. presence of a protective diode – diode symbol;
5. gate-source threshold voltage Uf.
For J-FET transistors:
1. conductivity – N-JFET, or P-JFET;
2. pinout in GDS=*** format.
For diodes (including double diodes):
1. pinout;
2. forward anode-cathode voltage – Uf.
For triacs:
1. type – Triac; 2. pinout in format G=*; A1=*; A2=*.
For thyristors:
1. type – Thyristor;
2. pinout in format – GAK=***.
The result is displayed on a two-line LCD. Testing time less than 2 seconds. (except for large capacitors), the result display time is 10 seconds. One button control, automatic shutdown. Current consumption in the off state is less than 20 nA. Resistance measurement range is from 2 Ohms to 20 MOhms. The accuracy is not very high. Capacitors are rated well from about 0.2nF to 7000μF. Above 4000μF the accuracy deteriorates. Measuring large capacitances can take up to one minute. The tester is not an accurate instrument and does not guarantee 100% reliability of identification and measurements, however, in the vast majority of cases, the measurement result is correct. When measuring power thyristors and triacs, problems may arise if the test current (7 mA) is less holding current.
Documentation
But among the radio components there are also those that are difficult, and sometimes impossible, to check with an ordinary multimeter. These include field-effect transistors (such as MOSFET, so J-FET). Also, a regular multimeter does not always have the function of measuring the capacitance of capacitors, including electrolytic ones. And even if such a function is available, the device, as a rule, does not measure another very important parameter of electrolytic capacitors - equivalent series resistance ( EPS or ESR).
Recently, universal R, C, L and ESR meters have become affordable. Many of them have the ability to test almost all common radio components.
Let's find out what capabilities such a tester has. The photo shows a universal tester for R, C, L and ESR - MTester V2.07(QS2015-T4). Aka LCR T4 Tester. I bought it on Aliexpress. Don’t be surprised that the device does not have a housing; with it it costs much more. option without housing, but with housing.
The radio components tester is assembled on an Atmega328p microcontroller. Also on printed circuit board there are SMD transistors with markings J6(bipolar S9014), M6(S9015), integrated stabilizer 78L05, TL431 - precision voltage regulator (adjustable zener diode), SMD diodes 1N4148, quartz at 8.042 MHz. and “loose” - planar capacitors and resistors.
The device is powered by a 9V battery (size 6F22). However, if you don’t have one at hand, the device can be powered from a stabilized power supply.
A ZIF panel is installed on the tester's printed circuit board. The numbers 1,2,3,1,1,1,1 are indicated nearby. Additional terminals on the top row of the ZIF panel (those 1,1,1,1) duplicate terminal number 1. This is to make it easier to install parts with spaced pins. By the way, it is worth noting that the bottom row of terminals duplicates terminals 2 and 3. For 2 there are 3 additional terminals, and for 3 there are already 4. You can verify this by examining the layout of printed circuit conductors on the other side of the printed circuit board.
So, what are the capabilities of this tester?
Measuring the capacity and parameters of an electrolytic capacitor.
I also advise you to look at the page that talks about the types of field-effect transistors and their designation in the diagram. This will help you understand what the device is showing you.
Checking bipolar transistors.
Let's take our KT817G as an experimental "rabbit". As you can see, the gain of bipolar transistors is measured hFE(aka h21e) and bias voltage B-E (transistor opening) Uf. For silicon bipolar transistors, the bias voltage is in the range of 0.6 ~ 0.7 volts. For our KT817G it was 0.615 volts (615mV).
It also recognizes composite bipolar transistors. But I wouldn’t trust the parameters on the display. Well, really. A composite transistor cannot have a gain hFE = 37. For KT973A, the minimum hFE must be at least 750.
As it turned out, the structure for KT973A (PNP) and KT972A (NPN) is determined correctly. But everything else is measured incorrectly.
It is worth considering that if at least one of the transitions of the transistor is broken, then the tester can identify it as a diode.
Checking diodes with a universal tester.
The test sample is a 1N4007 diode.
For diodes, the voltage drop across the p-n junction in the open state is indicated Uf. In the technical documentation for diodes it is indicated as V F- Forward Voltage (sometimes V FM). I note that with different forward current through the diode, the value of this parameter also changes.
For a given diode 1N4007: V F=677mV (0.677V). This is a normal value for a low frequency rectifier diode. But for Schottky diodes this value is lower, which is why they are recommended for use in devices with low-voltage autonomous power supply.
In addition, the tester measures and capacity p-n transition (C=8pF).
The result of checking the KD106A diode. As you can see, its junction capacitance is many times greater than that of the 1N4007 diode. As much as 184 picofarads!
If you install an LED instead of a diode and turn on the test, then during testing it will blink provocatively.
For LEDs, the tester shows the junction capacitance and the minimum voltage at which the LED opens and begins to emit. Specifically for this red LED it was Uf = 1.84V.
As it turned out, the universal tester also copes with testing dual diodes, which can be found in computer units power supplies, voltage converters for car amplifiers, all kinds of power supplies.
Double diode test MBR20100CT.
The tester shows the voltage drop on each of the diodes Uf = 299mV (in the datasheets it is indicated as V F), as well as the pinout. Do not forget that dual diodes come with both a common anode and a common cathode.
Checking resistors.
This tester does an excellent job of measuring the resistance of resistors, including variable and trimmers. This is how the device determines a trimmer resistor type 3296 at 1 kOhm. On the display, the variable or trimmer resistor is shown as two resistors, which is not surprising.
You can also check fixed resistors with resistance down to fractions of an ohm. Here's an example. Resistor with a resistance of 0.1 Ohm (R10).
Measuring the inductance of coils and chokes.
In practice, the function of measuring inductance in coils and chokes is no less in demand. And if large-sized products are marked with parameters, then small-sized and SMD inductors do not have such markings. The device will help in this case too.
The display shows the result of measuring the throttle parameters at 330 μG (0.33 milliHenry).
In addition to the inductance of the inductor (0.3 mH), the tester determined its resistance DC- 1 Ohm (1.0Ω).
This tester checks low-power triacs without problems. For example, I checked with them MCR22-8.
But a more powerful thyristor BT151-800R in the TO-220 case the device could not be tested and displayed the following message on the display: "? No, unknown or damaged part" , which loosely translated means “Missing, unknown or damaged part.”
Among other things, the universal tester can measure the voltage of batteries and accumulators.
I was also pleased that this device can test optocouplers. True, such “composite” parts can only be checked in several stages, since they consist of at least two parts isolated from each other.
I'll show you with an example. Here internal organization optocouplers TLP627.
The emitting diode is connected to pins 1 and 2. Let's connect them to the terminals of the device and see what it shows us.
As you can see, the tester determined that a diode was connected to its terminals and displayed the voltage at which it begins to emit Uf = 1.15V. Next, we connect 3 and 4 outputs of the optocoupler to the tester.
This time the tester determined that a regular diode was connected to it. There is nothing surprising. Take a look at internal structure optocouplers TLP627 and you will see that a diode is connected to the emitter and collector terminals of the phototransistor. It bypasses the terminals of the transistor and the tester “sees” only it.
So we checked the serviceability of the TLP627 optocoupler. In a similar way, I was able to test a low-power solid-state relay type K293KP17R.
Now I’ll tell you which parts this tester cannot check.
Powerful thyristors. When checking the BT151-800R thyristor, the device showed on the display bipolar transistor with zero hFE and Uf values. Another instance of the thyristor was determined to be faulty. This may indeed be true;
Zener diodes. Defines as a diode. You will not get the main parameters of the zener diode, but you can make sure integrity P-N transition. The manufacturer claims correct recognition of zener diodes with a stabilization voltage of less than 4.5V.
When making repairs, I still recommend not to rely on the readings of the device, but to replace the zener diode with a new one, since it happens that the zener diodes are working properly, but the stabilization voltage “walks”;
Any microcircuits, such as integrated stabilizers 78L05, 79L05 and the like. I think explanations are unnecessary;
Dinistors. Actually, this is understandable, since the dinistor opens only at a voltage of several tens of volts, for example, 32V, like the common DB3;
The device also does not recognize ionistors. Apparently due to the long charging time;
Varistors are defined as capacitors;
Unidirectional suppressors are defined as diodes.
A universal tester will not remain idle for any radio amateur, and will save radio mechanics a lot of time and money.
It is worth understanding that when checking faulty semiconductor elements, the device may determine the type of element incorrectly. So, a bipolar transistor with one broken p-n junction, it can identify as a diode. And swollen electrolytic capacitor with a huge leakage can be recognized as two back-to-back diodes. This has happened. I think there is no need to explain that this indicates the unsuitability of the radio component.
But, it is worth considering the fact that incorrect determination of values also occurs due to poor contact of the part pins in the ZIF panel. Therefore, in some cases it is necessary to reinstall the part into the panel and carry out testing.
I would like to share a very useful circuit for every radio amateur, found on the Internet and successfully repeated. This is indeed a very useful device, which has many functions and is assembled on the basis of an inexpensive ATmega8 microcontroller. There are a minimum of parts, so if you have a ready-made programmer, it can be assembled in the evening.This tester accurately determines the numbers and types of terminals of a transistor, thyristor, diode, etc. It will be very useful for both beginning radio amateurs and professionals.
It is especially indispensable in cases where there are stocks of transistors with half-erased markings, or if you cannot find a datasheet for some rare Chinese transistor. The diagram is in the figure, click to enlarge or download the archive:
Types of tested radioelements
Element name - Display indication:
NPN transistors - "NPN" on display
- PNP transistors - "PNP" on display
- N-channel-enriched MOSFETs - on display "N-E-MOS"
- P-channel-enriched MOSFETs - on display "P-E-MOS"
- N-channel-depletion MOSFETs - displays "N-D-MOS"
- P-channel-depletion MOSFETs - display "P-D-MOS"
- N-channel JFET - "N-JFET" on display
- P-channel JFET - "P-JFET" on display
- Thyristors - on the display "Tyrystor"
- Triacs - on the "Triak" display
- Diodes - on the display "Diode"
- Double cathode diode assemblies - on the display "Double diode CK"
- Double-anode diode assemblies - on the "Double diode CA" display
- Two diodes connected in series - “2 diode series” on the display
- Symmetrical diodes - on the display "Diode symmetric"
- Resistors - range from 0.5 K to 500K [K]
- Capacitors - range from 0.2nF to 1000uF
Description of additional measurement parameters:
H21e (current gain) - range up to 10000
- (1-2-3) - order of connected terminals of the element
- Presence of protection elements - diode - "Diode symbol"
- Forward voltage – Uf
- Opening voltage (for MOSFET) - Vt
- Gate capacitance (for MOSFET) - C=
The list shows an option for displaying information for English firmware. At the time of writing, Russian firmware appeared, with which everything became much clearer. You can download files for programming the ATmega8 controller here.
The design itself is quite compact - about the size of a pack of cigarettes. Powered by a 9V Krona battery. Current consumption 10-20mA.
To make it easier to connect the parts under test, you need to select a suitable universal connector. Or better yet, several - for different types of radio components.
By the way, many radio amateurs often have problems testing field-effect transistors, including those with an insulated gate. Having this device, you can find out in a couple of seconds its pinout, performance, junction capacitance, and even the presence of a built-in protective diode.
Planar SMD transistors are also difficult to decipher. And many radio components for surface mounting sometimes cannot be even roughly determined - either a diode or something else...
As for conventional resistors, here too the superiority of our tester over conventional ohmmeters included in DT digital multimeters is evident. Here, automatic switching of the required measurement range is implemented.
This also applies to testing capacitors - picofarads, nanofarads, microfarads. Simply connect the radio component to the device sockets and press the TEST button - all the basic information about the element will immediately be displayed on the screen.
The finished tester can be placed in any small plastic case. The device has been assembled and successfully tested.
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