Tonghui TH2821A LCR Meter

John S <sophi.2@invalid.org> wrote:
 
> BTW, these are also available for those large, TH electrolytics already 
> on the board:
> 
> Item 320702317637
> 
> Cheers,
> John S

Good News - those came with the TH2821A.

I have been trying to figure out how they make them into Kelvin contacts. 
The contact pads are two sided pcb. I think they may use one side for the 
exciting signal and the other side for the sense. It appears they do the 
same with the clips, since there are separate leads going to each side.

I put a thin dab of vaseline on the contacts. That provides a bit of 
lubrication to minimize wear. It also removes the surface oxides and grime 
and allows a true metal-to-metal contact. This reduces the contact 
resistance by a factor of ten and stabilizes it. Old radio engineer's trick 
from the 1930's

Thanks,

Mike

There are numerous eBay vendors that still offer the TH2821A. The prices 
vary quite a bit, but it looks like dealexcel-com has the best offer at the 
moment. They want US $185.65, but the shipping is now free. That's where I 
got my unit, but the shipping was extra.

If you are interested in getting one, I'd go with them. They already know 
about the problem with the 220VAC adapter not working in the US, and they 
shipped a replacement that goes from 100VAC to 220VAC so it should work 
anywhere.

They send the Kelvin clips with the unit, so you don't have to buy them 
separately. They also handle the smd probe, so you can combine the entire 
order in one package.

Thanks,

Mike

Mike wrote:

<snip>

> 
> 
> That looks identical to the TH2821A!
> 
> 
>>I also bought a $50 LCR that I use for everyday purposes:
>>http://www.amazon.com/Sinometer-MS8222H-Digital-Multimeter-Meter/dp/B00
>>0MFIDC0. It's OK, but sometimes I have to fiddle with the switch
>>and/or the leads to get continuity.
> 
> 
> Yes, I have a bunch of dmms. Some measure capacitance, but none measure 
> ESR. You need that to weed out the bad electrolytics in eBay boat 
> anchors.
> 
> 

You can build a go/no go ESR "meter" that'll find the bad 'lytics
for next to nothing.  Worth doing, unless you (psychologically)
_must_ have a "real" esr meter.

Ed

> You talked  me into it, Mike. The specs look super to me  and I've
> been needing something like it.

> Do you  get  probes  with  it so  you  can  test  components  on a
> populated board?

> Thanks for the find.

> John S

Sorry, John. I completely missed your question for some reason. Just
to confirm,  the  TH26027  Kelvin test cable  probe  comes  with the
TH2821A. It  is listed as an accessory on page 4  of  the Operator's
Manual:

"http://www.aidetek.com/New_products_info/Datasheet/tonghui/2821A.pdf"

and also listed in the datasheet:

"http://www.aidetek.com/New_products_info/Datasheet/tonghui/2821data%
20sheet.pdf"

I checked the continuity from the two-sided contact pad to  the test
clip. The  connections  are all individual  and  separate  from each
other, so  it  is  a  true Kelvin  connection  all  the  way  to the
component.

Pretty good for a $185US instrument!

Just make sure you get the Universal 100-220VAC adapter.

Thanks,

Mike

On 11/3/2011 3:20 PM, Mike wrote:
>> You talked  me into it, Mike. The specs look super to me  and I've
>> been needing something like it.
>
>> Do you  get  probes  with  it so  you  can  test  components  on a
>> populated board?
>
>> Thanks for the find.
>
>> John S
>
> Sorry, John. I completely missed your question for some reason. Just
> to confirm,  the  TH26027  Kelvin test cable  probe  comes  with the
> TH2821A. It  is listed as an accessory on page 4  of  the Operator's
> Manual:


Well, I already bought another set. But, that's okay.


> "http://www.aidetek.com/New_products_info/Datasheet/tonghui/2821A.pdf"
>
> and also listed in the datasheet:
>
> "http://www.aidetek.com/New_products_info/Datasheet/tonghui/2821data%
> 20sheet.pdf"
>
> I checked the continuity from the two-sided contact pad to  the test
> clip. The  connections  are all individual  and  separate  from each
> other, so  it  is  a  true Kelvin  connection  all  the  way  to the
> component.
>
> Pretty good for a $185US instrument!
>
> Just make sure you get the Universal 100-220VAC adapter.
>
> Thanks,
>
> Mike

Maybe I'll send him an email to remind him.

Thanks for the clue.

John S

John S <sophi.2@invalid.org> wrote:
> 
> Well, I already bought another set. But, that's okay.

You talked me into it. I can think of several projects where this would 
come in handy. You can never tell when these things will disappear, so I 
got a set also.

Thanks for the pointer!

Mike

I suspect Mike and John are bots.

I will now test.

Hey Mike!
You pathetic blob of useless DNA that didn't get aborted fast enough 
with a Black and Decker router.
You're a parasitic garbage making mindless consumer robot that will die 
unhappy in your own filth.
You're a fat ugly unwanted unsuccessful unloved uninteresting cockless 
guy who lives in a basement with his psychotic crack addicted mother.

On 11/3/2011 9:00 PM, D from BC wrote:
> I suspect Mike and John are bots.
>
> I will now test.
>
> Hey Mike!
> You pathetic blob of useless DNA that didn't get aborted fast enough
> with a Black and Decker router.
> You're a parasitic garbage making mindless consumer robot that will die
> unhappy in your own filth.
> You're a fat ugly unwanted unsuccessful unloved uninteresting cockless
> guy who lives in a basement with his psychotic crack addicted mother.
>

I had a tiny amount of respect for you until you pulled this crap out of 
your ass.

On 11/5/2011 10:53 AM, John S wrote:
> On 11/3/2011 9:00 PM, D from BC wrote:
>> I suspect Mike and John are bots.
>>
>> I will now test.
>>
>> Hey Mike!
>> You pathetic blob of useless DNA that didn't get aborted fast enough
>> with a Black and Decker router.
>> You're a parasitic garbage making mindless consumer robot that will die
>> unhappy in your own filth.
>> You're a fat ugly unwanted unsuccessful unloved uninteresting cockless
>> guy who lives in a basement with his psychotic crack addicted mother.
>>
>
> I had a tiny amount of respect for you until you pulled this crap out of
> your ass.

I do wonder which was more offensive. Being accused of being a bot or my 
test insults.

On 11/5/2011 1:45 PM, D from BC wrote:
> On 11/5/2011 10:53 AM, John S wrote:
>> On 11/3/2011 9:00 PM, D from BC wrote:
>>> I suspect Mike and John are bots.
>>>
>>> I will now test.
>>>
>>> Hey Mike!
>>> You pathetic blob of useless DNA that didn't get aborted fast enough
>>> with a Black and Decker router.
>>> You're a parasitic garbage making mindless consumer robot that will die
>>> unhappy in your own filth.
>>> You're a fat ugly unwanted unsuccessful unloved uninteresting cockless
>>> guy who lives in a basement with his psychotic crack addicted mother.
>>>
>>
>> I had a tiny amount of respect for you until you pulled this crap out of
>> your ass.
>
> I do wonder which was more offensive. Being accused of being a bot or my
> test insults.


I hope you die wondering. Soon.