LCR Tweezers test and analysis (HP-990, DT71, ST5S...)

[Shannon]

Some high-precision Wheatstone bridges use AC excitation to avoid low-frequency noise.

But if power consumption and temperature rising of large current are acceptable, DC large current is a more easy choice.

Depends on the use case.
If you want to find a short on circuit board, you will need to do it in DC or a low frequency. Otherwise you will measure the caps, plus the board layout will add inductance, so you will be mislead. Just keep the voltage low enough to no to fry components. Well, you could go fancy and test through pulsed excitation, but then you are in the area of the higher end tools.
If you have 1 component that you want to test, then AC could be better.

By the way, for testing on boards in the milli-ohm range it is best to avoid tweezers: contact surface and pressure have too much influence on the measurement, and are relatively hard to control with tweezers. Use pointy kelvin probes, and they are hard to find (the battery test kelvin probes are easy to find, but they are way too large). For those who want to see how its done, look what Robrenz did. Deep respect for his skills.

Shocked me, Deep Respect!

[Shannon]

I already wrote earlier in another topic, and attached photographs. 
Kelvin probes with a short distance are easy enough to make from felt-tip pens and sewing needles. 
Shielded wires.  Closed relay contacts and tracks between contacts are clearly distinguished on the boards.
  Relay resistance is higher;)
And my tweezers are HB-1.  The first of the HB series.  We have already written about them above in the topic.  (NV-14, NV-15).

Your design is very creative

Do you use the sewing needle to make the probe?
What a smart choice!

[Shannon]

Shannon,

Please, can youy let me know when you start sell it?

Best Regards.

Hi fabriciofx,

We have conducted many experiments, but we still attempt to get more ideas and help to make it better or make it true.

We are experienced in how to design a product, but we have few ideas on how to sell

Some guys recommend Kickstarter to me, is Kickstarter convenient for you?

Regards

[tautech]

Be aware you will need to compete with the Mastech MS8911 if you are to enter the low cost SMD tweezer market.

[Shannon]

Be aware you will need to compete with the Mastech MS8911 if you are to enter the low cost SMD tweezer market.

Hi tautech,

Really appreciate your reminding

If we try to make it true, our goal is that the performance is no worse than st5s, and the test results give us confidence at present 

[indman]

I know of a few really serious tweezers that are worth the cost, like the HB-14 or the newer HB-15.
But I don't know if these tweezers are sold in your countries, since the author and manufacturer of these devices is from Russia.

Similar tweezers are sold here under the names LCR-Reader-MP and LCR-Reader-MPA
https://secure.lcr-reader.com/catalog/product_info.php/products_id/94
https://secure.lcr-reader.com/catalog/product_info.php/products_id/87

[bateau020]

Similar tweezers are sold here under the names LCR-Reader-MP and LCR-Reader-MPA

It may be a bit confusing, but the LCR-Reader series and the ST-5S series come from the same place. See https://lcr-reader.com/
LCR-Reader* = consumer model. ST* = pro model.

[indman]

Available model LCR-Reader-MPA Pro 

[serg-el]

Siborg Systems Inc. the thieves. The design of the LCR-Reader-MP body was developed by the author back in 2011.
And everything else was stolen too.

https://www.lcr-reader.com/lcrreadermp.html
http://rlc-esr.ru/forum/index.php?topic=14.0

Video from the author from 2013.
https://youtu.be/iulsbC9Gj-0

[Shannon]

Siborg Systems Inc. the thieves. The design of the LCR-Reader-MP body was developed by the author back in 2011.
And everything else was stolen too.

https://www.lcr-reader.com/lcrreadermp.html
http://rlc-esr.ru/forum/index.php?topic=14.0

Video from the author from 2013.
https://youtu.be/iulsbC9Gj-0

It subvert my understanding.

So LCR-Reader-MPA and LCR-Reader-MP has the same circuit with HB14? 

and smart tweezers series, such as ST5S/Colibri, are similar with HB1 as well? 

[tautech]

The SMD tweezers marketplace is full of confusion with one brand copying the IP of another.
AFAIK these are the originals of which I still have their now 10+ year old ST3:
https://www.smarttweezers.com/

A quick test for another thread.
10uf 0805 in the plastic tape and 330uf between the screws of the tweezers

[WaveletSea]

http://www.rlc-esr.ru/index.php/ru/multimetr-pintset-nv15
http://www.rlc-esr.ru/index.php/ru/kupit/%D0%BF%D0%B8%D0%BD%D1%86%D0%B5%D1%82-%D0%BD%D0%B215-1-2028-detail

This one looks very cool.
Did someone has already one ?

[ceut]

Hello,
I'm looking for SMD Tweezers, and I find this topic 
So I have checked this new Russian one for buying it: http://www.rlc-esr.ru/index.php/ru/pintset-nv17
It seems to be a great tool !    Avalaible in January.
But it seems that it is only sold locally in Russia.
Also, I have looked at the LCR-MPA canadian tweezer, and it seems the canadian are copying like this:
HB-15 => LCR-Reader-MPA
HB-16 => LCR-Reader-R2
HB-17 => maybe LCR-Reader- ? ? ?
HB-17 new feature (taken from HB-16 // HB-17 seems to be a mix of HB-15 and HB-16):


But the canadian sells all at astronomical price
And no link for product fimware update, only User Manual.
Whereas the Russian model has update.

Will the HB-17 also be copied by the canadian when it will be out ?

Also, is there a way to buy the Russian model somewhere ?

Thanks 

[tautech]

ceut, member Shannon has his SMD tweezers available from his shop on Aliexpress and here’s his thread of the development progress where many have contributed to the end design.

As a happy customer I have zero reservations in recommending the ST42 SMD tweezers from Shannon.
https://www.eevblog.com/forum/testgear/design-a-new-precision-lcr-tweezers/

[ceut]

ceut, member Shannon has his SMD tweezers available from his shop on Aliexpress and here’s his thread of the development progress where many have contributed to the end design.

As a happy customer I have zero reservations in recommending the ST42 SMD tweezers from Shannon.
https://www.eevblog.com/forum/testgear/design-a-new-precision-lcr-tweezers/

Hello Tautech,
As always, you are really good for advices 
I'm checking for this tweezers on Youtube reviews and on the link you gave me + his website: it seems to cover all my needs so I go to buy one
And it comes from an eevblog user so it is a big argue for me 

Thank you! And happy end of year holidays