I assembled this tester using information from various forums. There are several options for circuits (but not as many as firmware)
The result is a compact, inexpensive device that does not require precise details in the circuit, convenient and functional!
Types of parts tested:
(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 - display "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 "Thyristor"
- Triacs - on the display "TRIAC"
- Diodes - on the display "Diode"
- Double-cathode diode assemblies - on the display "Dual diode CA"
- Double-node diode assemblies - on the display "Double diode CC"
- Two diodes connected in series - the display shows "2 diodes in series."
- Symmetrical diodes - on the display "2 counter diodes"
- Resistors - range from 1 Ohm to 10 MOhm [Ohm,KOhm]
- Capacitors - range from 0.2nF to 5000uF
Description of additional measurement parameters:
- H21e (current gain) - range up to 1000
- (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=
Fuses for PonyProg
You can also adjust the measurement constants using PonyProgC AndR The cells are marked in the photo.
We change the number in the middle cell of the buffer in increments of + or - 1 (depending on which direction you need to make the edit and by how much, it can be the number 10),
after changing the number in the cell, program the MK, then do a test of the known part, compare before and after.
We repeat the procedure if necessary.
Firmware for ATmega8 and ATmega8А, in the archive (English and Russian EEPROM, correct display in Cyrillic µ
And Omega) Tr-TestNew_11_01_2011.rar
Lay printed circuit board, for 1602V indicator, download the archive here Tester_P-P.rar
By and large, there is no special setup and adjustment of the device; amateurs, of course, can adjust the R and C readings, as it seems this has already been described in detail and there shouldn’t be any problems either.
So on the author’s website, I looked at what you need to pay attention to when starting up and setting up the device.
My translation is free, but I think the meaning is completely the same.
Troubleshooting
If something starts to show on the display, check the following parameters:
Is the connection to the LCD correct (we check the wiring of the LCD indicator using the datasheet)?
With HD44780 LCD compatible controller?
Check the fuses of the ATMega8 bits, correct (internal 1 MHz oscillator)?
Is EEP flashed? file, read into the EEPROM of the controller?
Perhaps the LCD needs to adjust the contrast voltage. The resistance must be adjusted in any case the LCD is adjusted to obtain good contrast (use a potentiometer if necessary).
If the board is assembled on the components of the correct configuration, and the correct order of connection to the probes shows that the component is detected, although it is not connected, or data such as the gain for different connection sequences diverge significantly, look for flux residue on the tracks, poor flux composition or similar soldering components need to be reviewed and cleaned. Between the tracks on the change. The probes should not contain any residual flux component. Flux is usually slightly conductive, causing current to leak through the flux and distort the result.
That's it, these are the global recommendations,
nothing new and nothing special, (the condition of using the nominal values of the parts is observed first of all) you only need to look at installation errors, and I’ll tell you this, it’s not always easy, because it’s easier to find a mistake in others than to admit your mistake (just kidding).... ....
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 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.
Discuss the article TESTER OF SEMICONDUCTOR RADIO ELEMENTS ON A MICROCONTROLLER
I had already assembled a similar tester, but I decided to make another traveling version, since sometimes such a device is needed outside the home - for example, when repairing radio equipment on call. The circuit diagram is shown below, since the size is large, this is a reduced copy. Click on it.
To power the device, it was decided to use a lithium-ion battery from an old mobile phone; the Chinese phone had already died, but the battery was still full and ready to power the devices. So, having removed the controller and soldered the leads, it was successfully placed in the body of the future device and was perfectly suitable for this circuit, both in parameters and in size.
It was decided to use part of the converter on the board, which was originally designed for measuring zener diodes using 328 megas with a large memory capacity and great functionality, as a converter to operate from such a battery. Having selected the ratings, I achieved the optimal efficiency and voltage, which is converted from approximately 4 volts to 9 volts.
The display is connected through a specially sealed connector, and connecting the display through stands and bolts makes the structure more durable, especially since everything is fixed with strong glue against unscrewing and loosening of the connections.
The board has a small number of low-scarce spare parts, the heart of the device is a mega-8 microcontroller, a converter on a 34063 chip.
Connectors for measuring smaller spare parts are a deep socket (bed) for microcircuits, and for larger ones - a prefabricated terminal block with 2+2 clamps, which are sealed in parallel with the socket.
To ensure that the battery does not run out completely, the automatic shutdown mode built into the firmware after 5 measurements is used; if the part is not connected, the device goes into standby mode, while the device display turns off and the device consumes not 150 mA, but 10-15 mA - then There is only the converter that works and nothing more, but in order to completely eliminate discharge when you are about to put the device in your pocket, there is a power switch that completely disconnects the battery and the board when you press the button.
The "test" button, used when testing parts, is not fixed, it is self-returning. The plastic case was bought at a hardware store for 15 rubles, good non-bulging soap dishes were delivered, all the boards fit just right and there was almost no free space left inside.
The charging connector, when connecting an external connector, turns off the device circuit and connects only to the battery for charging (a kind of built-in switch in the device). You can download all the files necessary for repeating the tester in general
The article describes a device - a tester of semiconductor elements (transistortester). The prototype of this device is an article posted on one of the German sites, authored by Markus. Similar articles can be found on the Internet, but the device deserves attention, and for this reason I will repeat it.
The tester accurately determines the pinout and types of transistors, thyristors, diodes, and also determines resistors and capacitors.
It is especially convenient for determining SMD components, which is why it was made. It will be very useful not only for a beginner radio amateur.
Types of parts tested:
(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 - display "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" (Russian - "Thyristor")
- Triacs - on the display "Triak" (Russian - "TRIAC")
- Diodes - on the display "Diode" (Russian - "Diode")
- Double-cathode diode assemblies - on the display "Double diode CK" (Russian - "Double diode CC")
- Double-node diode assemblies - on the display "Double diode CA" (Russian - "Double diode CA")
- Two diodes connected in series - on the display “2 diode series” (Russian - “2 diodes in series”)
- Symmetrical diodes - on the display "Diode symmetric" (Russian - "2 counter diodes")
- Resistors - range from 1 Ohm to 10 MOhm [Ohm,KOhm]
- Capacitors - range from 0.2nF to 5000uF
Description of additional measurement parameters:
- H21e (current gain) - range up to 1000
- (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=
You can also use PonyProg to adjust the measurement constants C and R (the cells are marked in the photo below).
We change the number in the middle cell of the buffer in increments of + or - 1 (depending on which direction you need to make the edit and by how much, it can be the number 10),
After changing the number in the cell, we program the MK, then we do a test of the known part, comparing before and after.
We repeat the procedure if necessary.
Firmware for ATmega8 and ATmega8A, archived (English and Russian EEPROM, correct display in Cyrillic µ And Omega) Proshiva.rar
Another set of various firmwares (English and Russian) Proshivki.rar
Various options for printed circuit boards and contact boards (for testing SMD elements), download the archive here.Pechatki.rar
It is probably better to assemble a circuit without auto-shutdown (the first circuit), since it is simpler, and auto-shutdown sometimes starts to get on your nerves. After pressing the "Test" button, the indication lasts 10 seconds, then the display and power are turned off. This was done in order to save battery energy, but if you install the indicator without backlighting (in principle, it is not needed), then the tester’s current consumption will not exceed 15 mA and the auto-shutdown circuit is unnecessary.
In general, by and large, there is no special setup and adjustment of the device; amateurs, of course, can adjust the R and C readings; it seems that this has already been described in detail and there should be no problems either.
Initially, the author recommended the Atmega8-16PU microcontroller for use in the tester; it is not available everywhere. The Atmega8L-8PU microcontroller is more affordable, and this is the most accurate replacement for the Atmega8-16PU in this AVR-Transistortester.
These MKs are flashed with the same firmware and there is no particular difference in operation and virtually no adjustments are required for R and C.
Yes, this tester is also not a high-precision device, namely a tester for determining radioelements, and mainly SMD elements, and it does not measure capacitance and resistance with high accuracy. He may also have some problems;
Problems in identifying conventional field effect transistors:
Since with most field-effect transistors the drain and source differ little or almost no difference when measured, they may not be recognized or recognized incorrectly, but in principle the type of transistor is shown correctly in any case.
Problems can also arise when determining powerful thyristors and triacs due to the fact that the available current when measuring 7 mA is less than the holding current of the thyristor.
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 obvious. 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.
