Products > Test Equipment
Bench LCR Recommendations?
Martin72:
--- Quote from: nctnico on May 31, 2023, 08:48:51 pm ---Those TH2830 / TH2832 look mighty interesting.
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Yes, the devices from tonghui/sourcetronic fill a gap between the very cheap ones from e.g. East Tester and the "big" ones from R&S, Keysight.
But also GWInstek, they want to have real money for their bench meters(up to 40000€..).
For a device with 100khz you are then over 2000€(LC6100):
https://www.reichelt.de/lcr-meter-lcr-6100-digital-100-khz-lcr-6100-p176048.html?PROVID=2788&gclid=Cj0KCQjw4NujBhC5ARIsAF4Iv6ff_KhaDAcTg5XskuzXJL9vq7spJnW3kFPT8r6sOFUQJdisplwnWVkaAnZCEALw_wcB
Whereby that is not better, only more expensive. And it looks very similar...
Our "Tonghui" (Sourcetronic) is as already said, very well made and exists for 3 years every external calibration without having to be readjusted.
--- Quote --- Can somebody enlighten me to a situation that higher voltage would be helpful?
--- End quote ---
AFAIK for some types of caps.
nctnico:
--- Quote from: KungFuJosh on May 31, 2023, 09:02:45 pm ---
--- Quote from: nctnico on May 31, 2023, 08:48:51 pm ---Those TH2830 / TH2832 look mighty interesting. Only thing they don't have is external DC bias which would be handy to have (up to 25V or so).
--- End quote ---
I've only ever tested at 1V. Can somebody enlighten me to a situation that higher voltage would be helpful?
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It is handy for checking whether MLCC capacitors meet their spec and/or how much they vary under DC bias. Selecting the right MLCC capacitor for a circuit can be a tedious job.
mawyatt:
--- Quote from: nctnico on May 31, 2023, 09:36:25 pm ---
--- Quote from: KungFuJosh on May 31, 2023, 09:02:45 pm ---
--- Quote from: nctnico on May 31, 2023, 08:48:51 pm ---Those TH2830 / TH2832 look mighty interesting. Only thing they don't have is external DC bias which would be handy to have (up to 25V or so).
--- End quote ---
I've only ever tested at 1V. Can somebody enlighten me to a situation that higher voltage would be helpful?
--- End quote ---
It is handy for checking whether MLCC capacitors meet their spec and/or how much they vary under DC bias. Selecting the right MLCC capacitor for a circuit can be a tedious job.
--- End quote ---
Exactly, one of the many reasons we developed the DC Bias adapter awhile back. This works really well, and with the SMD fixtures also mentioned, one can quickly access how a ceramic cap behaves, or misbehaves ::)
We found even the quality Samsung MLCC vary, mostly due to the ceramic formula utilized tho. Another interesting use is studying the reverse and slightly forward bias PN junction equivalent capacitance vs voltage, and a zener when entering breakdown.
The usual electrolytic and tantalum caps are also worth investigating.
One very interesting topic we haven't seen discussed is investigated the Miller Capacitive effect in bipolar and Mosfet transistors under certain bias conditions, this is on our "to do" list when we get some free time.
Anyway, after some research, we were one of the early adopters of this TH2830, and not disappointed in the acquisition decision awhile back. Now we've developed some plotting routines which produce nice plots, this is icing on the cake ;D
Pretty sure some of the upper tier equipment suppliers are using Tonghui as a source, some of the fixtures look quite similar if not exactly like Tonghui fixtures, except they cost much more ;)
https://www.eevblog.com/forum/projects/bias-network-for-lcr-meter
https://www.eevblog.com/forum/testgear/cheap-smd-lcr-fixture-the-good-bad-and-ugly
https://www.eevblog.com/forum/testgear/lcr-meter-plot-software
Best,
KungFuJosh:
--- Quote from: mawyatt on May 31, 2023, 11:13:59 pm ---Pretty sure some of the upper tier equipment suppliers are using Tonghui as a source, some of the fixtures look quite similar if not exactly like Tonghui fixtures, except they cost much more ;)
--- End quote ---
The Tonghui fixtures aren't cheap either though. 🤣
I think the normal price for the TH26007A or TH26008A is around $350, but you can find it for half that (taking the gamble whether it's real or not). The real ones usually have 4 connector levers, the fake ones usually only have the outer 2...still a gamble though.
EDIT: Holy crap, Batman! I just saw what Hioki charges for the same thing. 🤯🤯🤯
mawyatt:
If you do your research you can find some genuine Tonghui fixtures at reasonable prices, we got TH26009B Tweezers that are OEM. We don't use them very often, altho they are good to 15MHz!!
Yep, the Hioki equipment is expensive, thankfully all the Tonghui fixtures fit and work fine on the IM3536, we made absolute sure of that before ordering :-+
The cheaper no-name SMD fixtures seem OK, especially if you check out, tighten and mod them as we've shown. We fooled around with one and tried to see if we could use it for temperature sweeps by raising the plunger mechanism above the top surface plate and use a chassis mount 10W resistor as the heating element for the DUT. The chip is placed on the top surface of the resistor insulated by polyamide tape, and thermistor is attached just above the DUT area with thermally conductive tape. This kinda worked OK for static temperature tests, but wasn't repeatable for sweeps, and we abandoned the concept. The main issue was the plunger prongs would conduct heat away from DUT and you needed to wait much too long for thermal equilibrium. We even tried to "cheat" by measuring the DUT temperature with a chip thermistor as the DUT, this is how we knew the DUT temperature relative to the heating resistor mounted thermistor, and fitting a polynomial to estimate the actual DUT temperature vs sweeps, but too much uncertainty for our liking, so idea was trashed. Steady state could work but would require very long wait time between temperature changes for acceptable repeatability, too long for our patience :-\
Best,
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