Test/Review of Component tester Fish8840

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HKJ
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Test/Review of Component tester Fish8840
Component tester Fish8840

DSC_7173

This is a fairly universal component tester, it can recognize a lot of different component types and give some parameters for them.
It is also fairly cheap on ebay



How does it look


DSC_7174 DSC_7181

DSC_7177 DSC_7179
DSC_7180

The circuit is very simple, the microprocessor do everything. It has 3 pins connected to each of the 3 terminal, one directly for ADC, the two other pins with different resistors between (R1..R6).

DSC_7176 DSC_7256

The SMD area has a good layout on this circuit and will work with many different SMD parts.

DSC_7175

The two rows on the connector is in parallel..



Resistors

res

DSC_7240

My short did have some resistance. The reason for the slightly high resistance in the 10 ohm test is probably also due to the test wires.



Capacitors

cap

DSC_7239

I used extension wires for some of the measurements, this is the reason for the high ESR values.



Inductors

ind

DSC_7241



Diodes

diodes

DSC_7248 DSC_7247

A Zener is shown as two diodes with different Vf.
Because the test voltage is limited to 5 volt, it cannot detect any zener diode above that.



SCR (Thyristors) + Triacs

SCR

DSC_7734

It is not very good at detecting SCR or triacs, probably because the current is to low. As can be seen the graphic is also missing.



BJT (Bipolar junction transistors)

BJT

DSC_7250

It can detect most transistors, but an old germanium power transistor failed. It does not detect the resistors in the darlington transistors.
The terminals on a triac is not names A, C and gate, but usual MT1, MT2 and Gate.



FET (Field effect transistors)

FET

DSC_7251 DSC_7252

All mos transistors was detected.



IGBT (Insulated gate bipolar transistor)

IGBT

It could not handle the IGBT.



Voltage regulators

Vreg

Voltage regulators are not supported.



Technical details

Components are tested with 5 volt signals.
When on the current consumption is 10mA to 25mA.
When off the current consumption is 166uA, this will drain the battery in 5 few months. Oops!



Conclusion

The tester will recognize many different components and show the values. For passive parts the precision is fairly good.
It can recognize the common semiconductors, but fails on some more special types. There is also the "problem" that any testing values shown for diodes, BJT and FETS are at unspecified conditions and the values will change with conditions.
The off current consumption is way too high, because it is a loose circuit board, I do not see it has a big problem. It is easy enough to remove the battery when finished with the testing.

For the money it is a good tester for both leaded and smd parts.



Notes

This tester is based on this design:
Original design article in German
Improved design (czech clone)
Software

About the testing of testers

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

HKJ
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I was in doubt where to publish this review, but I believe this is the best place.

I strongly recommend reading the "About the testing of tester" article I have linked to, it contains some explanation.

I will test a few more components testers, but do not expect a new review each week.

If anybody has idea for other components to include or other tests to do, please post it and I will maybe include it in the next reviews.

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

MRsDNF
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Thanks HKJ. I believe for someone like me that does not have much of an idea about electronic components that this would be terrific aid in helping to learn.

 

djozz quotes, "it came with chinese lettering that is chinese to me".

                      "My man mousehole needs one too"

old4570 said "I'm not an expert , so don't suffer from any such technical restrictions".

Old-Lumens. Highly admired and cherished member of Budget Light Forum. 11.5.2011 - 20.12.16. RIP.

 

HKJ
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MRsDNF wrote:

Thanks HKJ. I believe for someone like me that does not have much of an idea about electronic components that this would be terrific aid in helping to learn.

The only thing you will learn from it is what components you have. It can be very useful if you buy component mix or have a "various parts" bin.

If you are going to use color coded resistors, it is also very useful to check that you read the code correctly (A ohm meter can, of course, also be used for this).

With smd capacitors and resistors it is an easy way to check the value.

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

bmmeadors
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Thanks for the review, HKJ!

I was actually looking for an ESR meter. This thing fills that and so much more. Also, FastTech has some good deals on bulk resistors and other components. I have purchased some in the past for various electronic repairs. I can see this being great for sorting those out. I don’t want to have to mess with band color charts and all that crap.

dchomak
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bmmeadors wrote:
Thanks for the review, HKJ!

I was actually looking for an ESR meter. This thing fills that and so much more. Also, FastTech has some good deals on bulk resistors and other components. I have purchased some in the past for various electronic repairs. I can see this being great for sorting those out. I don’t want to have to mess with band color charts and all that crap.

I learned those color band charts years ago, and let me tell you, that is by far the best way to do it. Once you learn it, one can spot any value resistor in a pile very quickly. The color sequence that you are looking for will jump right out at you. The problem these days is that the components are too small to use the color codes anymore.

EDIT: BTW, I also have this component checker and I love it!

texaspyro
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Here is a version of the tester with newer firmware. It can do things like measure and generate frequencies. It also draw the triac symbol.

http://www.aliexpress.com/item/12864-LCD-GM328-transistor-tester-ESR-meter-Cymometer-square-wave-generator-Free-shipping/2052241237.html

texaspyro
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dchomak wrote:
I learned those color band charts years ago!

Bad Booze Rots Our Young Guts But Vodka Goes Well.

texaspyro
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BTW, it is fairly easy to fix the standby power problem. When fishboy did his version he hooked the battery voltage checker divider resistors (2 × 47K) directly across the battery connection. You can move the input to those divider resistors to the input pin of the voltage regulator (i.e. after the power switch transistor). The standby current goes down to less than a microamp.

One issue that I had with my checkers is they would immediately switch off if you used a fresh battery. A 2 ohms resistor in series with the battery fixed that. The problem also went away when I replaced the 78L05 voltage regulator with an LM2936 ultra low power regulator.

dchomak
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texaspyro wrote:
dchomak wrote:
I learned those color band charts years ago!

Bad Booze Rots Our Young Guts But Vodka Goes Well.

OK,

Get Some Now. Wink

eas
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Thanks. One thing I’ve tried to find out is which of the “ready-made” versions of this design are compatible with the mainline opensource firmware.

texaspyro
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eas wrote:
Thanks. One thing I’ve tried to find out is which of the “ready-made” versions of this design are compatible with the mainline opensource firmware.

That can be hard to determine. The open source firmware does have a graphics driver for the most common 128×64 display, but it does not draw those pretty pictures of the component. Also at lot of the graphics based clones have a different voltage divider ratio on the battery check circuit… the firmware does have a #define for changing that. To use the open source firmware you are best off finding a unit with the text-mode LCD display and a ATMEGA328 CPU chip in a socket (or at least an ISP programming header).

This unit (and the aliexpress one linked to above) have do have a rather up-to-date firmware with a graphics display and the processor is in a socket.

http://www.ebay.com/itm/GM328-transistor-tester-ESR-meter-Cymometer-square-wave-generator-/251653350287?pt=LH_DefaultDomain_0&hash=item3a97b5638f

WarHawk-AVG
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aliumas147
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Hello, boght my self http://www.ebay.com/itm/12864-LCD-Transistor-Tester ,but allmost imidiatly coocked with charged cap Sad , disided to salvage part, and realised that lcd is not regular pinout and library is based on arduino 1.0. Can anyone help with powering up LCD (pins: GND, VCC, SID, SCLK, RS, RPST, CS )

PedroDaGr8
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If I remember correctly most of these boards are based off of the project buy the guys here:
$20 ESR LCR Transitor NPN PNP MOSFET meter (the site is having problems right now, but should be back up soon)

While this is not the central hub per se, there is a LOT of discussion about the firmware behind these meters and a couple of the authors chime in with their variants. This includes getting other LCD screens to work and what not. For those that are looking for some general basic functionality, these aren’t bad. The ESR function is limited, just like most ESR meters (other than True LCR meters). If you are looking for a true LCR meter, these are not what you are looking for; but that is a discussion for another thread (don’t want to derail this one with a discussion on a different device).

EDIT: Here is the main site where this entire design originated (warning it is in German) Here is the repository for the firmware. Markus is the m-branch, trunk is the k-branch. They offer similar features, just by two different authors.

EDIT2: This tester has some phenomenal documentation (in English) which breaks down all of the circuits, the circuit theory, etc. It is over 100 pages of details. This documentation can be found here Download the GNU Tarball, then use a program like 7zip to extract the pdf files.

PedroDaGr8
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Madires just released a new version of the firmware:
http://www.mikrocontroller.net/svnbrowser/transistortester/Software/Markus/

According to Madires:

Quote:
I’ve just released trendy 1.19m with fancy pinout for 3-pin semiconductors, driver for ILI9341/ILI9342, color display support and some bug fixes: