When is the 10KHz Tonghui vs 10 KHz Agilent LCR review coming? - Page 1
Forum section: electronics / general

author: Wartex
author_rank: Frequent Contributor
timestamp: May 25, 2011, 08:41:57 pm
content: subj.Can't wait any longer

author: Wartex
author_rank: Frequent Contributor
timestamp: May 28, 2011, 10:47:02 pm
content: Dave, you said you will compare the two, any word on this?

author: EEVblog
author_rank: Unknown
timestamp: May 29, 2011, 12:51:14 am
content: I don't remember saying that.I don't have a Tongui and have not tried to get one.Dave.

author: Wartex
author_rank: Frequent Contributor
timestamp: May 29, 2011, 01:40:36 am
content: I was referring to thishttps://www.eevblog.com/forum/index.php?topic=3440.msg45844#msg45844I guess by "same as their B model" you meant that new Agilent is same as older Agilent "B" model. I thought you referred to Tonghui's B model.This is the LCR meter I'm referring to:http://www.tonghui.com.cn/en/goods/index/250.htmlI think BK and Agilent's LCR meters are made by these guys because every time they release a model, it's 1 step behind Tonghui.

author: EEVblog
author_rank: Unknown
timestamp: May 29, 2011, 03:38:44 am
content: No, both the BK Precision and Agilent LCR meters are based on the same design from Escort which Agilent bought.BK and now Agilent have come out with their own refined designs that deviate from the Escort original.Nothing to do with TonghuiDave.

author: valentinc
author_rank: Regular Contributor
timestamp: June 08, 2011, 02:01:18 pm
content: I bought a couple of weeks ago a LCR meter from Tonghui, the model TH2822, and as I expected the board layout and components are identical to the BK Precision 879B from Dave's review, except that Tonghui uses another small board for the probe connectors ... And what I want to ask Dave is: can I get the firmware update from the BK Precision site (that one that fixes the MIN/MAX/AVG problem) and put in my Tonghui ? (considering that the microcontroller and the CPLD are the same, like all the board) . This way I will not only solve the MIN/MAX/AVG problem (which Tonghui also have), but also will upgrade the test frequency to 10 Khz, and I'm tempted to do that ...From what I've seen the only problem would be that the buttons configuration will be different, but let's say that I'll live with that, it's not a problem to me

author: tinhead
author_rank: Super Contributor
timestamp: June 08, 2011, 07:10:28 pm
content: Quote from: valentinc on June 08, 2011, 02:01:18 pmcheck pictures of both boards, if they exact the same you have a chance that this will work, but ONLY if the firmware update is doing CPLD and µC update!If not, don't try it (unless you can programm something else and send back as broken ...) - even if the PCB might be the same, only BK and Tonghui knows what inside CPLD,so in worst case the BK µC firmware will not work with Tonghui CPLD firmware (and vice versa)

author: valentinc
author_rank: Regular Contributor
timestamp: June 08, 2011, 07:36:22 pm
content: I don't understand what you're trying yo say: you mean that it could be possible that the intern architecture of the uC and CPLD to be different, even if they have the same part number ? Because if their internal architecture is identical, i don't see why the BK firmware won't work ...And it's clear that a firmware update cand only modify the CPLD and/or microcontroller, because the rest are discrete components (like op-amps, CMOS 4000, 74HC series).

author: tinhead
author_rank: Super Contributor
timestamp: June 08, 2011, 09:12:06 pm
content: Quote from: valentinc on June 08, 2011, 07:36:22 pmwhich part isn't clear ?Quote from: valentinc on June 08, 2011, 07:36:22 pma CPLD is programmeble logic device, the actually used Altera MAX II EPM240xxx does have 192 logic macrocells.So no just imagine you have 192 logic ICs, how many combination of function can you build with them ?And now supprise, exact same problem for µC - it didn't matter what on the empty name is on the chip anddidn't matter how these two chips are interconnected, what's matter is the function inside.There no indication that BK and Tonghui are using exact the same protocols, procedures or whatever- the only common thing (if PCBs are really exact the same way routed) might be the measurments way.I give you another (more visual) example, ATTEN and RIGOL DSOs - both looks from outside different, both have totallydifferent firmwares - but if you look inside they looks exact the same.This means ATTEN might work properly if you burn RIGOL firmware (DSP and CPLD!!!) and vice versa- and yes if you burn BK firmware into CPLD and µC the Tonghui device will work, and vice versa too.But to be very honest, you can't actually do this.Why ? Well, very simple, the firmware update on BK website doen NOT include CPLD code.You maybe wondering now why, that's simple too - everybody who have CPLD and µC firmwarecan easily produce own clones.Even if Tonghui and BK would be (or are) designed by same developers team, it might happens that each of themis using different checksum or protection in the bootloader (which is actually common practice for OEMs).But hey, nothign simple like this, connect the Tonghui device to PC, connect via Terminaland try to run the update - and you will see what happens.Sur eit can be that both companies are lazy and bootloader will accept the code and CPLD will be programmed in exactsame way making the BK firmware working with no issues - but the chance is not that big.If you brick the Tonghui, you will need at least to erase the µC before you send it back, lol

author: carloscuev
author_rank: Regular Contributor
timestamp: November 19, 2011, 03:01:48 am
content: Quote from: valentinc on June 08, 2011, 07:36:22 pmSorry for bringing this up again, did you tried replacing the firmware? Did you have luck?I'm looking to transform my TH2822A to TH2822C, at least I would like to have the battery charging functionality, dont know if only soldering missing components will work !

author: EEVblog
author_rank: Unknown
timestamp: November 19, 2011, 04:32:25 am
content: Agilent have said they the new C series LCR meter will be in the post shortly.Interestingly, they were not keen to have it compared to the IET LCR meter...Dave,.

author: valentinc
author_rank: Regular Contributor
timestamp: November 19, 2011, 03:40:08 pm
content: I didn't try to change the firmware in my Tonghui TH2822, because I'm pretty sure that without any modifications, it would not work at all.About the battery charging, from what I can see on the board, there are missing a few resistors and capacitors, a diode, and an IC ... The problem is: you need a Tonghui TH2822C to see what values have those components and what IC is that. If you can find out what parts are needed, you can do it, I'm sure that the charging circuit isn't digitally controlled by the microcontroller

author: don.r
author_rank: Frequent Contributor
timestamp: November 19, 2011, 04:58:11 pm
content: Quote from: EEVblog on November 19, 2011, 04:32:25 amSo.... that means your going to compare them, right?That Tonghui looks like a lot of meter for $400.