Fnirsi -TC3

[indman]

A tester doesn't need to be precise or advanced, but it’s good if it's versatile. There are plenty of these testers, and they are based on software by Karl-Heinz Kübbeler, which the Chinese have cloned and sell under names like LCR-TC1, TC2, TC7, etc. These are the best cheap devices and are even relatively accurate.

Your statement is only true for the LCR-TC1, TC2, TC7 clones that were on sale before and which are based on the AVR ATmega.
The clones of the LCR-Tx series, which are now sold by Chinese friends, are based in the same way as FNIRSI products on specific controllers and are only a parody in the form of a disposable toy and are not at all similar to the original German project.

[Phil1977]

But the cheapest of these clones just use the architecture of the original Karl-Heinz Kübbeler design and you can often flash them with the open source software.

The devices like the Fnirsi TC3 just implement (probably against all GPL rules) the open source software into a closed proprietary product. If fnirsi stops the support, no one can help you anymore.

Regarding this aspect the cheaper clones are the better.

[indman]

But the cheapest of these clones just use the architecture of the original Karl-Heinz Kübbeler design and you can often flash them with the open source software.

Not exactly, you're wrong. Chinese firmware for such clones is blocked for reading. If the controller burns out, the author's firmware can only be downloaded if you install a new Atmega and if the pinout on the PCB allows it.

[CharlotteSwiss]

Thanks guys, maybe I didn't understand what the advantage of these tweezers is. If the advantage is only to use one hand, then I don't need them. I thought that these little tools were better for measuring SMD with low values. Better than a multimeter.
I already have 4 multimeters and I also have the famous LCR T4 of which I attach the image.
Maybe I misunderstood, I thought that these tweezers were more precise on the measured values ​​of my instrumentation.

[tautech]

I saw that there would be Shannon, but the price is too high for an amateur... A middle ground would be fine. Even my multimeters indicate resistance (in addition to sound) in continuity tests. What I have a hard time understanding is why these tweezers should be better than a multimeter. I hope it's not because you can use them with one hand...

If you do general repair ST42 is a very useful tool.
Cap ESR and LED test capability are what I've found the most useful recently plus all the other things SMD tweezers can do of course.

Nearly 2 decades of SDM tweezer use and couldn't be without them....far more useful than a DMM for measuring components.
And don't think they limit you to testing only SMD components............

[CharlotteSwiss]

If you do general repair ST42 is a very useful tool.
Cap ESR and LED test capability are what I've found the most useful recently plus all the other things SMD tweezers can do of course.

Nearly 2 decades of SDM tweezer use and couldn't be without them....far more useful than a DMM for measuring components.
And don't think they limit you to testing only SMD components............

I have always measured the ESR caps on my lcr T4. So with tweezers is it possible to measure it even with the component on the circuit? But the value expressed may not be too truthful, I imagine. Bye 

[tautech]

If you do general repair ST42 is a very useful tool.
Cap ESR and LED test capability are what I've found the most useful recently plus all the other things SMD tweezers can do of course.

Nearly 2 decades of SDM tweezer use and couldn't be without them....far more useful than a DMM for measuring components.
And don't think they limit you to testing only SMD components............

I have always measured the ESR caps on my lcr T4.

We each have our own ways of measuring what we need but I started my smart tweezers journey nearly 2 decades back after borrowing a benchtop LCR nulling bridge and shortly after also got into SMD.

That I also couldn't measure unmarked SMD caps always annoyed me, armed with just a DMM so I took the plunge and spent big for me at that time (long before tautech days) on a top of the line brand of SMD smart tweezers which served me well until ST42 came along which are next level and some.
ST42 has proven itself to be a many tools in one device and all I need for component measurement.

So with tweezers is it possible to measure it even with the component on the circuit? But the value expressed may not be too truthful, I imagine.

Experience has taught me to be very wary of any in-circuit measurements and only when I can see the circuit is simple or there are no parallel paths will I trust such measurements.

[KungFuJosh]

In circuit is always iffy. So are any ESR measurements from the TC1/2/3 etc devices.

[Phil1977]

But the cheapest of these clones just use the architecture of the original Karl-Heinz Kübbeler design and you can often flash them with the open source software.

Not exactly, you're wrong. Chinese firmware for such clones is blocked for reading. If the controller burns out, the author's firmware can only be downloaded if you install a new Atmega and if the pinout on the PCB allows it.

I can't confirm this. I have two chinese clones that could be programmed with the open source firmware. They still have a brownout problem - that´s why I want to install a new MCU anyhow - but not too soon.

[indman]

I have always measured the ESR caps on my lcr T4. So with tweezers is it possible to measure it even with the component on the circuit? But the value expressed may not be too truthful, I imagine.

You can test capacitors with a T4 even in a circuit. For this purpose, the author's firmware has a special mode C/ESR-in circuit, which reduces the measurement voltage on the test pins to 0.3V. Many owners of such clones even adapt special tweezers with protective diodes, so as not to damage the ports of the controller high voltage and it was more convenient to test the parts in the circuit. But, as you have correctly noted, the validity of such measurements in the circuit will be about 50/50, however, as with similar meters.
In-circuit measurements presuppose a lot of experience in such cases and a good knowledge of the circuitry of those nodes on the board, which you check.

I can't confirm this. I have two chinese clones that could be programmed with the open source firmware.

What controller are your clones built on?

[CharlotteSwiss]

Thanks friends, of course I know that the measurements on the circuit are often wrong. In the last board I'm checking, more than half of the measurements do not match, but I have to say that for 90% I know very well that the components are good. I had never thought of checking the components on the circuit with my T4. In fact, two probes with a suitable connection to the slot would be enough. Obviously only circuits not under voltage (and discharged caps).

[indman]

In fact, two probes with a suitable connection to the slot would be enough. Obviously only circuits not under voltage (and discharged caps).

Yes, you are right, but even experienced users sometimes have problems with in-circuit tests when they forget to discharge the capacitances or there is still a residual charge on them, which can easily damage the measuring ports of the device. 
If you want to buy a relatively inexpensive($40-60) i advise to you but complete universal RLC measurement bridge XJW01.
This Chinese device can conduct in-circuit measurements, can be supplemented with convenient tweezers and Kelvin connectors, has a full-fledged 4-wire connection, has been tested by time and many users, has a high basic measurement accuracy of 0.3% and with proper calibration and adjustment can provide a small error of 0.1-0.2%.

[CharlotteSwiss]

In fact, two probes with a suitable connection to the slot would be enough. Obviously only circuits not under voltage (and discharged caps).

Yes, you are right, but even experienced users sometimes have problems with in-circuit tests when they forget to discharge the capacitances or there is still a residual charge on them, which can easily damage the measuring ports of the device. 
If you want to buy a relatively inexpensive($40-60) i advise to you but complete universal RLC measurement bridge XJW01.
This Chinese device can conduct in-circuit measurements, can be supplemented with convenient tweezers and Kelvin connectors, has a full-fledged 4-wire connection, has been tested by time and many users, has a high basic measurement accuracy of 0.3% and with proper calibration and adjustment can provide a small error of 0.1-0.2%.

In fact, it's better that I don't invent something with the T4. In my safety notes when studying it, I wrote to download the caps well so as not to burn the Atmega.


For your advice, I write in the relevant topic (xjw01) 

[siealex]

A question for all users of DSO-TC3. Can you perform the following actions?
1. Take an electrolytic capacitor (e. g. 100 μF) and test it on the component tester.
2. Connect a low Ohm resistor (5..10 Ohm) in SERIES to the same capacitor and test again.
Will the ESR difference correspond exactly (within ~10%) to the additional resistor?

On my device:
220 μF 63 V Samwha SD: 209.2 μF 0.08 Ohm.
The same capacitor + 8.98 Ohm 0.5% resistor: 211.3 μF 1.2 Ohm (!!!). How on Earth?
On an old ATmega based component tester:
The same capacitor itself: 206.1 μF 0.19 Ohm.
With the resistor: 208.0 μF 8.49 Ohm. Slightly low (the correct value should be around 9.1 Ohm), but still reasonably close to truth.
The resistor itself displays 9.0 Ohm on BOTH TC3 and the old tester.

W. T. F.

[Phil1977]

I can confirm it.

100μF + 15 Ohm show ESR of 2.1 Ohm at the DSO-TC3
6.8 Ohm at a supercheap T7-tester
16 Ohm at the "most original" AVR-tester I have

Seems to be better not to trust the ESR values of the TC3.

[siealex]

Seems to be better not to trust the ESR values of the TC3.

However, the capacitance values are correct. How?

[watchmaker]

[Phil1977]

It seems the transistor tester results are to be taken with care in any case.

A super simple 5.1kOhm resistor is recognized as a double diode in the DSO-TC3:



And it´s not a fluke (pun intended), the TC3 repeatedly shows the same result - also with different pin connections.

The €7,- "T7 Tester" with the same resistor:



It seems FNIRSI just copied the transistor-tester code into it´s product with quite little care about how good it performs.

[Aldo22]

It seems the transistor tester results are to be taken with care in any case.

A super simple 5.1kOhm resistor is recognized as a double diode in the DSO-TC3:

Have you ever calibrated the thing?
That can help.
I have the DSO-TC2, but I am not aware of any such errors.

[Phil1977]

Have you ever calibrated the thing?

Yep. Didn't change a thing.

I checked it with a variable resistor: Between 4kOhm and 6kOhm I get the "2 Diodes" error. Other resistors seem to be okay. 

Probably the TC3 just got too complex for FNIRSI. The transistor tester code itself is an absolute miracle that needed years of debugging and lots of iterations. Putting it into another "all-in-one-wonder" may just be too much.

Just FYI, I have firmware V0.3

[Aldo22]

I checked it with a variable resistor: Between 4kOhm and 6kOhm I get the "2 Diodes" error. Other resistors seem to be okay. 

Probably the TC3 just got too complex for FNIRSI. The transistor tester code itself is an absolute miracle that needed years of debugging and lots of iterations. Putting it into another "all-in-one-wonder" may just be too much.

Hmm, now I have looked for a 5.1k resistor to check this.
The measurement on my TC2 is frighteningly accurate. 
Is this an individual problem with your device?

[KungFuJosh]

I never use it for this purpose, but mine detected 1.2k and 8.2k fine. Maybe you should try reflashing the firmware?

[Phil1977]

Values <4kOhm and >6kOhm are correctly detected with my device too.

@KungFuJosh: Can you try 5kOhm?

I´ll just stay using a DMM for resistors.

[madires]

I checked it with a variable resistor: Between 4kOhm and 6kOhm I get the "2 Diodes" error. Other resistors seem to be okay. 

IIRC, we had such an issue with the OSHW firmwares and a few odd testers a long time ago and fixed it by improving the filter for resistors in the diode detection function. My guess would be that someone didn't test that when porting the code (k-firmware in this case) to a different MCU.

[KungFuJosh]

Values <4kOhm and >6kOhm are correctly detected with my device too.
@KungFuJosh: Can you try 5kOhm?

Yes. I'll have to find one later though, that value is not in my bins. I'm sure I have one somewhere.

I´ll just stay using a DMM for resistors.

As well you should. LCR or DMM is the right tool for testing resistors. Also a lot easier than clipping things into the TC3.