Author Topic: Pintek PA622 Current Probe - Crap or just cheap ?  (Read 3094 times)

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Offline Martin72

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Pintek PA622 Current Probe - Crap or just cheap ?
« on: December 27, 2018, 05:09:56 pm »
Hi everyone,

A current probe for my scope would be nice to have but the prices (even used) are high.
So I´ve looked around and found this one:

https://www.ebay.de/itm/Pintek-Professional-Current-probes-up-to-100Khz-10mV-A-100mV-A-Range-3-5n-R/380412102263?hash=item5892540677:g:gwEAAOSwr81USGj3:rk:3:pf:0

Does anybody have experiences with this probe ?
It´s a noisy crap thing or is it just worth the price, also the specified accuracy worrying me ( up to 15% by greater current values).
Also alternative recommendations  are welcome.

Martin

Offline HighVoltage

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #1 on: December 27, 2018, 05:24:48 pm »
I do not have the Pintek PA622

But, for that price you can get a real branded FLUKE 80i-110s AC/DC Current Probe or the same re-branded as Tektronix, Agilent and so on.
I have several of these and they are really great and go on ebay in good condition for 200 to 300 Euros

There are 3 kinds of people in this world, those who can count and those who can not.
 

Offline Martin72

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #2 on: December 27, 2018, 09:52:15 pm »
Thanks for that !
But reading the specs, it got the same deviation up to 15% at higher current rates(from appx 40A on).
Maybe it couldn´t get any better in this price range.
I will have a look for it, I didn´t often measure on circuits which keeps more than 10, 20 A flowing.

Martin

Offline natman69

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #3 on: December 28, 2018, 10:21:33 am »
I'm also interested in this probe. Unfortunately I haven't found a technical review or a teardown. There is only a picture of inside.

Some trusted members of the forum recommend the CP-05A current probe (about 110 USD) but also in this case there isn't a technical review.

Hope someone will do a review of these probes soon...   ;)

In a different class of performance there is the Hantek CC-65 (about 65 USD). There are several threads on eevblog about this probe and a deep review with noise measurement and teardown.
 

Offline Martin72

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #4 on: December 28, 2018, 05:57:37 pm »
Thanks for that !

Additionally, I´ve found this one in eBay Owon CP-05+

(PDF)

The price is in the middle of the before mentioned probes..the quality too….? Makes me curious.

Offline natman69

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #5 on: December 30, 2018, 08:07:05 am »
In the same ballpark I've found Picotech current probes:

https://www.picotech.com/accessories/current-probes-clamps

The Picotech TA018 is very similar to the Hantek CC-65.

Instead CP-05 is available also as CP-05A, CP-05B and CP-05+ but I'm not sure about the performance differences.
 
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Offline Martin72

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #6 on: December 30, 2018, 10:45:37 pm »
Thanks for this, meanwhile I think I order the cp05 for testing.
Take it to work to compare it with probes from fluke, tektronix and lecroy ap011....


Offline Martin72

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #7 on: January 03, 2019, 10:15:58 pm »
Today I test the fluke i 310s probe....not the cheapest one..
Boy, what a noisefloor….. :o
You see nothing as long as you not use enhanced resolution or ( in case of the new rigol 5074) averaging…
And this one costs 3 times more than a Owon CP05....

Offline noidea

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #8 on: January 04, 2019, 05:13:55 am »
On the subject of cost effective current probes has anyone seen the "A622" AC/DC current probes on the bay of evil, and has anyone bought one? I wonder if they are the same quality as the originals

A622 is the model number of the Tektronix AC/DC probe that a lot of test equipment manufacturers rebadge and sell as their own (Fluke 80i-110S, Keysight 1146a/b etc etc) which to my knowledge were originally made by Chauvin Arnoux as the E3N
 

Offline Vtech

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #9 on: January 04, 2019, 11:48:50 am »
I have Pintek PA-699 and I'm quite happy with it. It's higher bandwidth version - 1.5MHz.
 

Offline noidea

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #10 on: January 16, 2019, 10:19:39 am »
Thanks for this, meanwhile I think I order the cp05 for testing.

Hi Martin72
Did you end up ordering a CP05?
 

Offline Martin72

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #11 on: January 16, 2019, 07:12:30 pm »
Hi,

Should arrive in this week….

Martin

Offline dmm2018

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #12 on: January 17, 2019, 03:42:43 pm »
Bought a Fluke i30s before and it's pulse current response was quite poor (the frequency of signal shown in figure below is 700Hz). Returned to Fluke but the problem could not be solved, then refunded. Bought Keysight 1146B and it's pulse current response is much better.

« Last Edit: January 17, 2019, 03:52:19 pm by dmm2018 »
 
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Offline joeqsmith

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #13 on: January 17, 2019, 07:02:20 pm »
Bought a Fluke i30s before and it's pulse current response was quite poor (the frequency of signal shown in figure below is 700Hz). Returned to Fluke but the problem could not be solved, then refunded. Bought Keysight 1146B and it's pulse current response is much better.



Forget the 700Hz, I wonder what the edge rates were.  Looks like it was picking up some noise. 

These are my DC current probes shown roughly a 200us pulse.   I think the LEM's 3dB point is 150K.  The old 1960's Tek probe was originally 50M.   I ended up getting close to 100K with the cheap UNI-T.   

1) gate pulse, TTL
2) modified UNI-T UT210E
3) LEM LA 55-P
4) modified Tektronix P6042
How electrically robust is your meter?? https://www.youtube.com/channel/UCsK99WXk9VhcghnAauTBsbg
 
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Offline Hydron

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #14 on: January 17, 2019, 08:05:05 pm »
As it may be of interest, I've attached a pdf summary of some tests I did on a PA-699 Pintek probe (the 1.5MHz 40A one) earlier year. These were quick and dirty checks, and the noise numbers in particular should be taken with a grain of salt, as I have some other screenshots which suggest pk-pk noise about twice as high as I've stated in the PDF. Unfortunately I don't have the original noise capture or the probe available for a re-test, but what is there might still be useful.

You're never going to get as good a result with one of these clamp-meter style probes as you will with a real Tek/Hikoi (who make them for everyone else) high frequency probe using a thin-film hall sensor and a DC-nulling design. However those are well into the thousands new (many hundreds for good tested used examples) so the Pintek style mid-range probes may be a good compromise choice for some.
 
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Offline Martin72

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #15 on: January 17, 2019, 09:45:12 pm »
Tomorrow the owon will be arrived.
I´ll test it on monday at work, together with the fluke i310s and as a reference, the lecroy AP011 probe.
This probe got 120khz bandwith and a maxium of 150A peak.
Yearly calibrated, matches only with lecroy scopes and you can do auto-zero compensation and....degaussing :D
What I can test at work:
DC current, AC current 50-400hz, current of an pwm-signal with 10khz up to 100A and more (depending from the testobject I could get)

Martin

Offline Martin72

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #16 on: January 18, 2019, 08:08:45 pm »
Arrived:





Short test without load, really less noise than the fluke i310s, on all ranges…
You  have to press the auto-zero knob as long as it reaches the zeroposition on scope - it works.
Maybe I can do some DC tests this weekend at home.
Edit:



Specs….
« Last Edit: January 18, 2019, 08:24:15 pm by Martin72 »
 

Offline Martin72

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #17 on: January 27, 2019, 11:48:30 pm »
I took it to work, unfortunately I couldn´t do some serious measurements yet.
Except some dc measure on the desktop, they´re looking good.
On the following week I could do further tests and report it here.

Offline Martin72

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #18 on: January 30, 2019, 06:22:48 pm »
Still waiting for a chance to measure…..
Meanwhile I checked the lower dc-current range, setting the cp05 to 4A range.
"Reference" was a Fluke 89IV and on Ch1 the lecroy ap011.
Current control mode by shortening the psu output.

Readout from the fluke : 100mA, 251mA, 500mA, 1.03 A dc current:


      







From 1Adc on the results from the cp05 are usable - not too bad for a currentclamp up to 400Adc.

 
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Offline Martin72

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #19 on: February 01, 2019, 06:00:25 pm »
AC-current measures today, in the 4A range - Under 1A it´s not usable.
Measurings taken with appx 3.9A and various frequencies.
"Reference" was Fluke 187.

          60Hz   400Hz   1khz  4khz  10khz  20khz

Fluke   3.86   3.87      3.84   3.75   3.54   3.14
LeCroy 3.84   3.82      3.79   3.67   3.35   2.77
CP05+ 3.89   3.90      3.81   3.81   3.64   3.21

So far so good…
But:
I´m sure I did a zero-offset before, both lines ( AP011 and CP05) were on zero-scaling before starting to measure.
Now I watch the screenshots at home…











(Ch1 Ap011, Ch 2 CP05+, for better viewing not in the same current flow direction)

Seems like a positive offset, althoug I did the zeroing before measure.
And:
The phase deviation between the two channels by increasing the frequency.

« Last Edit: February 01, 2019, 06:02:26 pm by Martin72 »
 

Offline Martin72

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #20 on: February 06, 2019, 06:59:45 pm »
Teardown:





Not much inside for the money.
Two pots on the back, Maybe I can adjust the positive offset with them.
Trying to make a schematic from it...

Offline Martin72

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #21 on: February 11, 2019, 10:16:43 pm »
Quote
Trying to make a schematic from it...

Still doing so further tests will come later.
The battery voltage is converted to +/- 3V - Too less for some of the used op-amps there.
A colleague and me think about modifications to make this probe useful for currents under 1A.
If the schematic is complete, it will be posted here.

Martin

P.S.:
The thread title schould be changed, but how…..

Offline Martin72

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #22 on: February 18, 2019, 10:10:38 pm »


Schematic so far, Lo Bat detection and +/-3V are missing.

Got a look into our Fluke i310S, much more "complicated" Building....this one is very simple.
All op-amps need a minimum supply of about +/- 5V.
Used op-amps there : OP07C, MC33078, TL062, TL064.

Martin
 
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Offline Martin72

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #23 on: February 19, 2019, 02:05:22 pm »
"Final" schematic:



(no guarantee)

Martin

Edit : The "zero switch" doesn´t switch "hard", it´s a rubber carbon one with a resistance of appx 80 \$\Omega\$ .
« Last Edit: February 19, 2019, 04:01:40 pm by Martin72 »
 

Offline Martin72

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #24 on: February 23, 2019, 09:53:38 pm »
"Final final" schematic, changed diode D1 into zener type:



Next steps : Further measurings, after this increasing the internal supply-voltage from +/- 3V to appx 10V to see what happen, reminding the 3 Volts are for EVERY op-amp in the circuit too less.

 
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Offline Martin72

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #25 on: February 25, 2019, 06:16:54 pm »
Today measuring a 300µs pulse, reference was a tektronix probe.

300mA:



2 A, tektronix :



Owon :



Noisy and overshoots….


Offline Martin72

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #26 on: March 30, 2019, 06:18:43 pm »
Further tests will come….at last.
Because:



Now I got two…..I´m joking, my clamp was damaged and I asked them for repair.
They won´t repair it, they also don´t want the defective clamp back, today I got a new one from them... :D 8)
So now I can do a full "teardown", first I took the cover from the jaw away:



Ah, only hall-sensors, no compensation coil….
I will clean up the pcb from any parts so I could have a better look to the layout, for completing the schematic.

Next week I take some measures on a "real DUT" with the new one.

Offline Martin72

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #27 on: March 31, 2019, 07:09:08 pm »
A Picture of the hall sensor, taken with the andonstar microscope:





Any idea which could be the brand/manufactor ?
Search with "4pins hall sensor smd" wasn´t succesful.


Offline analogRF

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #28 on: August 19, 2019, 04:13:21 am »
Martin,
did you increase the supplies to +/-5 to see what happens to measurements?
or any other tests?

 

Offline Hydron

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #29 on: August 19, 2019, 12:11:15 pm »
Any idea which could be the brand/manufactor ?
Search with "4pins hall sensor smd" wasn´t succesful.
It may be from Asahi Kasei, they make 4-pin hall elements for this sort of thing:
https://www.akm.com/akm/en/product/detail/0004/
 
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Offline Martin72

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #30 on: August 19, 2019, 06:33:58 pm »
Hi,

Quote
did you increase the supplies to +/-5 to see what happens to measurements?
or any other tests?

Yes, and a little bit higher  - Result was the damaged clamp…
Still I want to make further tests on work, the clamp is also there but time.... :(
 
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Online schmitt trigger

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #31 on: August 19, 2019, 08:17:18 pm »
Very interesting tear down, please continue.
 

Offline analogRF

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #32 on: August 19, 2019, 08:22:20 pm »
Hi,

Quote
did you increase the supplies to +/-5 to see what happens to measurements?
or any other tests?

Yes, and a little bit higher  - Result was the damaged clamp…
Still I want to make further tests on work, the clamp is also there but time.... :(

do you mean the hall sensor died? because the opamps shouldnt die with +/-5V or even higher
but the current passing through the hall sensor must be limited, so maybe when you increased the supplies the current through the sensor exceeded the limit

was there any change in noise level of the clamp?
 

Offline Martin72

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Re: Pintek PA622 Current Probe - Crap or just cheap ?
« Reply #33 on: August 19, 2019, 08:43:33 pm »
Hi,

Yes, the hall-sensor died  :(



Increasing the voltage in a region, where every op-amp would function proper was the intention.
And the hope, that the noise level would decrease, but it didn´t.
They claimed a bandwith of appx 200khz, which wasn´t so bad at all, but I can´t believe it, although the clamp did measure up to 10khz proper, as I test it a few month ago.

Quote
please continue.

I´ll desolder all the parts from the pcb of the defective one, to have a look at all connections( for finishing the schematic).



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