Author Topic: A peek inside the Voltcraft VC891 Handheld DMM  (Read 1488 times)

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Offline QOTF-AlexiTopic starter

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A peek inside the Voltcraft VC891 Handheld DMM
« on: May 09, 2024, 08:12:28 pm »
I recently bought this meter on Conrad.nl for €270 (normal price €299) and decided to follow Dave's advice and take it apart. I do not know much about multimeter guts but it doesn't look very impressive. I did not remove the metal shield because I didn't want to risk accidents, so we can only guess at the multimeter IC, although I suspect it might be identical to that of the Uni-T UT171, since Uni-T is the ODM of Voltcraft DMMs and the features of the UT171 seem similar. The knob is permanently attached to the front case.
Images: front & back of PCB, contents of box.
 

Offline QOTF-AlexiTopic starter

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Re: A peek inside the Voltcraft VC891 Handheld DMM
« Reply #1 on: May 09, 2024, 08:14:38 pm »
Some close up pics of the CPU, bluetooth module and stuff around the input jacks.
 

Offline joeqsmith

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Re: A peek inside the Voltcraft VC891 Handheld DMM
« Reply #2 on: May 09, 2024, 09:16:49 pm »
I'm not a fan of placing the vias in the center of the function switch contacts.  It looks like the typical 5mm PTCs are used without any additional limiting.   For $300 USD, I would expect a lot more.

Offline QOTF-AlexiTopic starter

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Re: A peek inside the Voltcraft VC891 Handheld DMM
« Reply #3 on: May 10, 2024, 06:49:01 am »
I've also run a few tests now and the resistance & capacitance meter, diode test and continuity test are very, VERY slow. For example it takes about 0.5-1 second for the beeper to sound on continuity and 2-15 seconds on resistance/capacitance, depending on how large or small your resistor/capacitor is. All the other functions are fast at least.
I do still have a no questions asked return window and I am low-key considering it, but then I'd have to fall back to my 1999 count Metex M3800, of which the calibration has drifted so far it's barely usable.
 

Offline HighVoltage

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Re: A peek inside the Voltcraft VC891 Handheld DMM
« Reply #4 on: May 10, 2024, 03:04:58 pm »
Voltcraft is the low end "in house" Conrad brand and the quality is not the best, to say it carefully.
I am surprised they can sell it for so much money.

For this amount of money, you can get something real good, used and new.


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

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Re: A peek inside the Voltcraft VC891 Handheld DMM
« Reply #5 on: May 12, 2024, 12:40:43 am »
I just had to have a lit selector switch too: https://www.eevblog.com/forum/testgear/121gw-lit-selector-switch/
« Last Edit: May 12, 2024, 01:09:58 am by J-R »
 

Offline Gyro

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Re: A peek inside the Voltcraft VC891 Handheld DMM
« Reply #6 on: May 12, 2024, 09:57:49 am »
I just had to have a lit selector switch too: https://www.eevblog.com/forum/testgear/121gw-lit-selector-switch/

How do they keep the LED stationary in center of the knob (presumably there is a rotating light guide)? I can't see any way of restraining it apart from the stiffness LED leads themselves going down the center hole.
Best Regards, Chris
 

Offline QOTF-AlexiTopic starter

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Re: A peek inside the Voltcraft VC891 Handheld DMM
« Reply #7 on: May 12, 2024, 10:06:33 am »
Going by the rest of the meter's innards, I would not be surprised if the LED is actually mounted at the end that lights up, with the wires tangling and untangling when the knob is turned.
 

Offline Gyro

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Re: A peek inside the Voltcraft VC891 Handheld DMM
« Reply #8 on: May 12, 2024, 10:34:40 am »
Yuk, I hope not.
Best Regards, Chris
 


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