Author Topic: Pintek PA622 Current Probe - Crap or just cheap ?  (Read 3083 times)

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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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Offline 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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