Cheap Current Probe Gets Good Review

A current probe isn’t a very common fixture on most workbenches because they are pretty expensive. [VoltLog] looks at a fairly inexpensive current probe from Micsig. He seemed impressed with the workmanship and it looks similar to more expensive offerings. There are two models with different bandwidth numbers (800 kHz and 2 MHz). It can measure current on a 10A and 100A scale.

According to [VoltLog] comparable probes from other vendors are more expensive and have lower bandwidth. He also liked that the device powers from USB since most newer scopes will have a USB port available.

If you aren’t familiar with a current probe, you might enjoy Digikey’s article on the topic or Keysight’s take on it. This probe can measure AC or DC current and while the specifications don’t promise super accuracy, [VoltLog] noted that his unit was better than the spec. He also noted that if you are wanting to measure small currents going to a microcontroller or similar device, these current probes are not really what you want to use.

We enjoyed the teardown of the device, too, about ten minutes into the video. The probe is surprisingly complex. It is possible that like some popular oscilloscopes, that changing the low bandwidth variant to the higher bandwidth model may be possible since the board appears to be used for both models.

We’ve looked at building very precise current probes. We’ve also looked at dirt cheap ones.

13 thoughts on “Cheap Current Probe Gets Good Review

  1. Is EVERYTHING on HaD a Youtube video? Has the written word and figures a completely forgotten art? Truly pathetic. I can read 10x faster than these silly videos, so no thanks, I miss the HaD of 10 years ago…

    1. I don’t read that quickly, but searching for content in an article is far easier than in a video. Videos are great for seeing something, for example the motion of a 3d printer mechanism, but the waffle level of most videos… Conversely, there are planned videos that contain so much great and specific content that I need to pause to keep up with the flow of info and ideas, for example, the Afrotechmods videos: that have appeared on HaD and I would recommend to anyone wanting to get into electronics. I have used them as inspiration for teaching material.

  2. Current probes are just so very useful and especially so if wide frequency response you can tailor now and then trying to track down things like triplen harmonics in 3 phase setups and related oddities. Also great for tracking down current paths in various older types of early SMPS power boards and the occasional oldie UPS swirching stages where a previous “repairer” swapped out different power transistors and fudged a ferrite core that looked the same but had different magnetic current properties – eek.
    I recall Hewlett Packard (HP) had a nice three probe set which included a smallish hall effect type current probe, had minor calibration issues but, a most useful piece of gear nonetheless so will be taking a peek at this thread in due course and interested in comments too, so thanks for posting :-)

    I do however, like the idea of a current probe which also simultaneously reports/records magnetic field vectors – there is some spooky stuff I’ve come across so got a pair of HP Interface Bus (HPIB) operated HP 60vdc 3Oamp supplies I will need to run on different 240v input phases with outputs in parallel and at low voltage paralleling 12 off 3000F super caps though only 2.7V each, what fun ! Good thing is the power supplies are nicely robust and programmable too, wish I could find a cheapie USB to HPIB though…

    1. The prologix usb-gpib is midway in price between the ebay specials and the entry level NI or keithley ones. I use NI at work and prologix at home and it’s done an excellent job. There are DIY usb-gpib boards but they’re fairly hard to get working, and it’s increasingly difficult to find the hardware driver chips, as mostly that’s been sucked into expensive asics.

  3. I hear you.

    I, too, hate that, but as Elliot says, that’s the culture [1] out there.

    For me, it’s not that much about videos per se (although it’s not my preferred way of understanding something) — rather it’s about not feeding the Big G, which is a repeat of the late 1990s dystopia “best viewed with Internet Explorer”.

    I just avoid them. One click less for them.

    In a way, I thank Hackaday, since they provide a written digest so I don’t have to go look myself.

    [1] Not only that. YT gives the authors a way to monetarize their work. If and when they’re lucky, that is. So authors try their luck.

    1. Yep. I still write an accompanying article when I have time. But they don’t get any traffic these days.

      Getting harder to justify taking the time to write something that doesn’t get any traction in search. Same thing in video form seems to at least get found by folks looking for it.

  4. If your interested in this then check out the UNI-T UT210E current clamp meter.
    Of the shelf it’s just a regular clamp meter, with no scope output, but there are tutorials for adding a scope output to this meter.
    You can expect a bandwith of around 2kHz, which is enough for mains voltage related measurements.

    I quite like this meter because it’s a quite small / compact clamp meter, also has voltage, diode, capacitor (auto) ranges and it has 3 manual current ranges of 100A, 20A and 2A in both DC and AC, and in the most sensitive range it has a resolution of 1mA. With this resolution it’s also sensitive to the earth magnetic field. You have to re-zero the meter when you rotate it!

    The biggest downside of this meter is that I would like it to be mechanically more robust, but it does get the job done as it is now.

  5. I agree that the over-use of video can be a waste of time for both the producer and reader. Some information is well suited for video presentation, but much is not. YouTube does provide a transcript which can offer some time savings in skimming the content to see if it’s worthwhile. The transcripts usually contain some funny misinterpretations, as a bonus. This one has “rodent shorts rtz co2” :-)

  6. The main issue I have with _some_ videos is simply that the producer doesn’t think like a producer, and all too many seem to be overly fond of their own voices. It’s an issue of getting the information density correct for the target audience, and that’s not often trivial, as the audience might not be what you think you targeted. What to make sure and say, and what to leave out so as not to bore the more advanced?

    As Tim G mentioned here, there are some things where video is far better than words – conveying dynamics and so on. And some things where the better specificity of words rules – no one really wants to see a page of your source code or equations in a video if they can’t have a copy in locally usable form, legible and stable enough for study. I make videos sometimes, and also write things up, and I’m not claiming either is easy – I know better, from experience, and I often fail. I’m sure my audience would agree about that fail part more often than not.

    The issue “out there” seems to be that there is so little recognition by the creators that it’s not just setting up a camera and go. That kind of borders on vanity to think you’re going to just be amazing without a plan.

    My Hantek CC 65 seems to work fine for me (so there’s a least a little info in this post).

    (not commenting on this video, as I’ve not watched it yet…)
    Ok, it badly needs an upfront “executive summary” for those who don’t need 15 min of talk about the product.

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