Design a New Precision LCR Tweezers with Much Lower Cost 【Shannon Tweezers ST42】

[KungFuJosh]

That's true, Shannon is awesome.

Still, he might need to tell people not to put the card in the case. 😉

[Personwithhats]

I mean you get a card why wouldn't I put it in the case

[KungFuJosh]

My tweezers live in the leather case...sticking out of my work bench next to another meter lol.

[shapirus]

What is the reference card, anyway? What are you talking about?

[tautech]

What is the reference card, anyway? What are you talking about?

Menu tree card.
It's a necessary reference card until you get to know these a bit. 

[TomKatt]

Stupid question of the day - I just received my ST42 tweezers and while it seems intelligently laid out, I’ve never used an LCR meter before…. The included documentation only shows the menu structure and doesn’t include any information on how to actually use them or why choose certain options such as frequency.  Is there a good reference somewhere that explains how to best use an LCR meter like these?

Also, is there a suggested calibration routine using the open/short calibration in addition to the autocal option?

[KungFuJosh]

Stupid question of the day - I just received my ST42 tweezers and while it seems intelligently laid out, I’ve never used an LCR meter before…. The included documentation only shows the menu structure and doesn’t include any information on how to actually use them or why choose certain options such as frequency.  Is there a good reference somewhere that explains how to best use an LCR meter like these?

Also, is there a suggested calibration routine using the open/short calibration in addition to the autocal option?

Autocal is often good enough by itself, but at least once in a while, or if something seems off, you should do the full open/short cal.

Frequency range depends on what you're measuring. Some things won't work, or not be as accurate in the wrong range. The attached image shows the ranges and relative accuracy for my ST2832. You can use that as a guideline. But I'd probably leave it in 1k most of the time, and adjust when needed. IIRC pressing the joystick up shifts through frequencies (I'm left-handed, it might be different from your position).

[Personwithhats]

It was the card 

Battery life is fine now. Card should have a warning label!

[ceut]

Hello,
I have received a new tool, a DSOTouch DS4T252, great and little DSO  , a little post and review here:
https://www.eevblog.com/forum/testgear/dreamsourcelab-dstouch-ds4t1012-ds4t1012/msg5588001/#msg5588001

I have made a funny measurement with my ST42: 2 great tools together mesuring each parts of the other one.

Great to see the ST42 in action again with checking all the real input characteristic of this DSO without a single problem   

[Grandchuck]

The Shannon tweezers here are more useful now.  A simple assembly of extension leads is shown below.  The push on terminals grip surprisingly well and provide a reliable means to extend the leads.  The terminals slide back off easily as well.

[Martin72]

Well, you can do it that way too.

[ceut]

The Shannon tweezers here are more useful now.  A simple assembly of extension leads is shown below.  The push on terminals grip surprisingly well and provide a reliable means to extend the leads.  The terminals slide back off easily as well.

It's a very good idea to check bigger components !
Sometimes I'm stuck at checking some parts on PCB with the ST42 because of their size, so I will try do something like this 

The only thing that I'm worry about is the friction/wear that could damage the "golden" tips 

[KungFuJosh]

The only thing that I'm worry about is the friction/wear that could damage the "golden" tips 

It's a replaceable part. Get a couple spare sets. 😉

[ceut]

It's a replaceable part. Get a couple spare sets. 😉

Yes I forget that, thank you 

The Shannon tweezers here are more useful now.  A simple assembly of extension leads is shown below.  The push on terminals grip surprisingly well and provide a reliable means to extend the leads.  The terminals slide back off easily as well.

So I have made my own tips extension, based on your idea, thank you 
I have found about the same push on terminal as yours, and have soldered a rigid copper on it.

I think @Shannon could make an official extension option we can plug on the original tip for big components , and he could sell this
(we have no news from him since some times, don't know if he goes here to check his topic  )

Some photos as always, with a super big Elna capacitor checking I can't do before

[TomKatt]

I think you need to be careful how long your extensions are because just adding to the tip loses the 4 wire interface.  At the very least you’ll probably need to calibrate the tweezers with the extension added to compensate for any added resistance and or capacitance.

Also, learn from me and be careful not to lose the tiny plastic insulator washers on the tip screws lol.

[ceut]

I think you need to be careful how long your extensions are because just adding to the tip loses the 4 wire interface.  At the very least you’ll probably need to calibrate the tweezers with the extension added to compensate for any added resistance and or capacitance.

Yes, I completely agree (and I saw that inside after teared it down to fix my USB/Serial problem), that's why I have taken a big rigid and short copper piece for the extension.
I think I lost the precision for Milli-ohms range, pF and µH.

But, for example: when I want to check the 400V capacitor on a PSU input unit (after discharging it of course ),
I'm very often stuck with the opening of the tweezers, and I put a little piece of wire to do the measurement...
So I think my extension would work in this case, without losing too much precision in the µF/Ohms range

[Martin72]

I had solved it a little more elegantly:
https://www.eevblog.com/forum/testgear/shannon-st42-lcr-tweezer-test-and-comparison-thread/msg5579359/#msg5579359

[ceut]

I had solved it a little more elegantly:
https://www.eevblog.com/forum/testgear/shannon-st42-lcr-tweezer-test-and-comparison-thread/msg5579359/#msg5579359

I have not seen that there was another ST42 topic 

Also ==> NEWS : I have just connected my ST42 on the Shannon Server because I was on the 1.5.4 firmware, and I saw that you have the 1.5.5 inside so I have upgraded it.
Now I'm on the 1.5.6 FW version !

And there are some visuals modifications. I have to check all now 

[Martin72]

Now I'm on the 1.5.6 FW version !

Welcome to the club:

https://www.eevblog.com/forum/testgear/shannon-st42-lcr-tweezer-test-and-comparison-thread/msg5572923/#msg5572923

 

[Frex]

Hello,

I tried to join the club, unfortunately I'm unable to order it on Aliexpress...
I always have the message below that saying promotion price sales  is reached ...
 Not very clear, nothing indicated on product page.
Does anybody encounter this issue ?
Regards.

Frex

[Shannon]

The Shannon tweezers here are more useful now.  A simple assembly of extension leads is shown below.  The push on terminals grip surprisingly well and provide a reliable means to extend the leads.  The terminals slide back off easily as well.

So I have made my own tips extension, based on your idea, thank you 
I have found about the same push on terminal as yours, and have soldered a rigid copper on it.

(we have no news from him since some times, don't know if he goes here to check his topic  )

Hello guys, I definitely read all of your posts.

I have gained a lot of support and confidence from them. So many good comments, each one is enough to make me happy for a night.
Thank you all, tautech, KungFuJosh, ceut, Grandchuck and so many guys.
And Martin72, I look forward your comparison work https://www.eevblog.com/forum/testgear/shannon-st42-lcr-tweezer-test-and-comparison-thread/
You were confused by everyone's praise, but still place the order with doubt, you tested it seriously and output hardcore works, which really made me nervous, maybe no more than two seconds  , I hope the ST42 didn't disappoint you

Thank you both, but I would like a concrete answer to my question about what makes this device better than cheaper ones to buy.

Thanks a lot for your question, I am also thinking about the answer to this question.


Good comments make me gain confidence, bad comments/suggestions make me progress.
Of course I still remember the original promise, good suggestions will be fed back.

Seeing that so many guys is trying to modify the measurement width of the tweezers, I really started to think about this seriously, especially Martin72's elegant work angered me, I hope to bring a modification that is more gorgeous than Martin72

Originally, I thought that large components are not so commonly used, and flying wires can also solve the problem when needed.
It seems that this is only true for me.
Especially some netizens were considering buying a bench LCR to support daily work, due to the tip of the tweezers was not wide enough

[Shannon]

Hello,

I tried to join the club, unfortunately I'm unable to order it on Aliexpress...
I always have the message below that saying promotion price sales  is reached ...
 Not very clear, nothing indicated on product page.
Does anybody encounter this issue ?
Regards.

Frex

Thanks for your support.
Have you tried contacting customer service?

I occasionally get these failed purchase questions, but I can't figure it out.
Because I can't place an order with my account, or even access the site from your perspective.
Aliexpress is a Chinese company that provides services to many countries and regions, but not China.

I can also ask customer service for you, but usually, they invest more in their customers than the merchants, and they will provide better support for your feedback.
Anyway, I will report your problem to customer service, and hope they can figure out what the hell is wrong with their platform

[Phil1977]

Originally, I thought that large components are not so commonly used, and flying wires can also solve the problem when needed.
It seems that this is only true for me.
Especially some netizens were considering buying a bench LCR to support daily work, due to the tip of the tweezers was not wide enough

Many people just don't trust small measurement instruments.

Once a colleague with own engineering background asked me for a power supply for some Helmholz-coils that needed around 15A at not much more than 1.5V. I gave him a CC buck-converter that was quite small and worked flawlessly.

A few days later I´ve seen he connected two 30V/10A linear power supplies in parallel that dissipated around 250W for that purpose. I asked him what was wrong with the buck converter, and the answer was he didn't trust it to deliver 15A continuously because it´s so small and doesn't get hot 

[Shannon]

Originally, I thought that large components are not so commonly used, and flying wires can also solve the problem when needed.
It seems that this is only true for me.
Especially some netizens were considering buying a bench LCR to support daily work, due to the tip of the tweezers was not wide enough

A few days later I´ve seen he connected two 30V/10A linear power supplies in parallel that dissipated around 250W for that purpose. I asked him what was wrong with the buck converter, and the answer was he didn't trust it to deliver 15A continuously because it´s so small and doesn't get hot 

Your story made me laugh to tears

Engineers need physical intuition, but not too much.

[tautech]

Especially some netizens were considering buying a bench LCR to support daily work, due to the tip of the tweezers was not wide enough

In approaching 2 decades of SMD tweezer use, one just adapts usage styles to suit the DUT, however in all those years rarely have I needed to extend DUT leads to obtain an indicative pass/fail measurement.

A quick rat into old components came up with a clamp mount, stud terminal 22,000uF 25V Nippon Cemi-Con with 22mm/7/8" terminal spacings of ~30mm outside on the studs......either measured without problem.....something beyond the capability of my leaded Fluke 15B < OL displayed. 

I can and do spread ST42 wider and can just manage 50mm at the tips.

Many people just don't trust small measurement instruments.

Then they lack experience.