Cleqee P4100 High Voltage Oscilloscope Probe 100:1 - Page 1
Forum section: electronics / testgear

author: Teti
author_rank: Regular Contributor
timestamp: May 28, 2021, 12:24:28 pm
content: Hi guys,any of you have tried this cheap High voltage probe? Obviously I would take these values with pinch of salt, but just wondering if any of you have experience with these cheap high voltage probes?I do fancy to get one for up to 300V measurements, but do not fancy to fork out 150 quid for differential (which I've had cravings for a whileThey say 2kV, but this really looks like normal probe with higher value resistor. cable is rather thin for 2kV?Cleqee P4100 High Voltage Oscilloscope Probe 100:1universal 100:1 high-voltage oscilloscope probeSpecifications:• 100:1 attenuation• Input resistance of 100 megohms• Input capacitance of 6 pF• Compensation range: 10 - 35 pF• Bandwidth: 100 MHz• Rise time: 3.5 ns• Maximum operating voltage: 2 KV (Vp-p)• Length: 1.2 metershttps://www.aliexpress.com/item/32704502182.html?spm=a2g0o.store_pc_topSellerIng.8148356.5.27726181IP79pQ

author: bob91343
author_rank: Super Contributor
timestamp: May 28, 2021, 10:04:27 pm
content: I don't call that high voltage. 2 kV p-p is only 1 kV peak. For a sine wave that is only about 700 Vrms.I would like to be able to view the high voltage in my linear amplifier, which is around 3.5 kV. This probe would create fireworks.

author: bdunham7
author_rank: Super Contributor
timestamp: May 28, 2021, 10:20:12 pm
content: I don't like HV probes with standard ends and ground clips. I'd recommend the P2301C style, which I have found quite satisfactory, even at 4kVp-p@ 20kHz.https://www.alibaba.com/product-detail/wholesale-P2301C-Oscilloscope-Probe-100-1_60656533263.html

author: joeqsmith
author_rank: Super Contributor
timestamp: May 28, 2021, 11:08:42 pm
content: I had bought a cheap one years ago. While testing it well below the derate curve, it became damaged. I cut it open and it had a standard 1/4 axial part in it. Hopefully you have better luck.

author: tautech
author_rank: Super Contributor
timestamp: May 28, 2021, 11:16:17 pm
content: Specialist probes are useless without access to the probe pamphlet and the derating curves.Wouldn't touch it with a 40' barge pole.

author: radiolistener
author_rank: Super Contributor
timestamp: May 28, 2021, 11:55:14 pm
content: I don't recommend to use it with mains or voltage above 200-300 V. This is not safe probe.But it can be useful if you're needs to measure 1-5 V signals with low probe capacitance.

author: Teti
author_rank: Regular Contributor
timestamp: May 29, 2021, 08:44:59 am
content: Quote from: tautech on May 28, 2021, 11:16:17 pmYep, that's exactly what I thought. Looks dodgy AF

author: tautech
author_rank: Super Contributor
timestamp: May 29, 2021, 09:29:39 am
content: Quote from: Teti on May 29, 2021, 08:44:59 amProbably not however if a seller advertises such things the full specs should be offered which includes the derating graphs.It's from the Pioneer range of probes (P6100 etc) and unless you know where to find the full specs one would be buying uninformed of its full capabilities.

author: Fraser
author_rank: Super Contributor
timestamp: May 29, 2021, 10:44:19 am
content: A cheap 2Kv probe tested against its provided derating curve. It died during testing. The video contains a teardown and what he found inside is both surprising and scary ! Built down to a price and placed inside a reasonable looking casing. Classic Sheep in Wolfs clothing = Junk.Just look at how much protection the reviewer employed and take note. When using a high voltage probe you are trusting it to not pass the high voltage to the test equipment as that can end badly. Always consider the worst case scenario and take suitable precautions. Blowing the front end of your oscilloscope could really spoil your day. As others have stated, it may be best to buy a recognised brand and quality of high voltage probe that provides trustworthy specifications and derating graphs. I have some 100:1 modular probes for low loading applications but they do not claim to be high voltage types. My high voltage probes come from Fluke and PMK. Not cheap, but then neither is a new DSO. I recommend the use of a decent over voltage protection device at the DSO input if experimenting with high voltage probes..... just in case Murphy strikes !https://youtu.be/v1jJ1Z_fgFU

author: joeqsmith
author_rank: Super Contributor
timestamp: May 29, 2021, 01:05:51 pm
content: Quote from: tautech on May 29, 2021, 09:29:39 amA few of the reviewers posted pictures of the manual.QuoteI would hope the majority of the voltage drop is at the probe tip and not the cable. That would be a bad thing...When I looked for a 100X probe, I was trying to sort out who made the ones for Keysight. I had bought some 10X probes from Hantek for about $10/ea that I still use. They offered a 100X version which is what I tried to buy but they were swapped out for that probe I show in the video.You mention you want something for 300V but you make no mention of the frequency requirements. If for example, you are one of those people that like to look at their AC lines, I would just use a step down transformer. If you are needing something for higher frequencies, you may want to check the used market.It's certainly possible to make your own probes but it may cost more than a good used one. Of course, if you are a beginner, it may also cost you a scope..There are several videos about it. The last probe I cobbled up from junk was a simple differential probe. This video goes over the basic design.

author: vk6zgo
author_rank: Super Contributor
timestamp: May 29, 2021, 02:53:07 pm
content: Quote from: radiolistener on May 28, 2021, 11:55:14 pmThat's what I used x100 probes for, back in the day---a cheap substitute for a (then costly,) high impedance, low capacitance, active probe.It did the job, not perfectly, because the reduced level resulted in a noisy display, but was adequate, & the Boss didn't have to fork out a "King's Ransom" for a rarely used device.That said, the big old x10 Tek probes as supplied with the 545b were quite adequate for looking at400-odd volts of ac or DC at relatively modest frequencies, as are the later, smaller ones, so the x100 was a bit of a "rare bird" itself for its supposed intended use.Of course, the older, analog 'scopes were usually amply rated for input voltage, modern DSOs maybe not so much.

author: joeqsmith
author_rank: Super Contributor
timestamp: May 29, 2021, 03:31:53 pm
content: I had built one of Bob Pease's FET probes which worked well. For higher frequencies, I still use resistive probes. Both of these wouldn't be very good for higher voltages.Dave made a video with a friend of his on a homemade HV probe.I made a few videos on my large probe. This one shows the basic design.

author: bdunham7
author_rank: Super Contributor
timestamp: May 29, 2021, 04:50:25 pm
content: Quote from: tautech on May 29, 2021, 09:29:39 amThe problem with the probe thatjoeqsmithburned up is that the derating curve is the most bogus thing about it. The P2301C type I have, which appears to be modeled after the Tek P5122, comes with a derating curve that clearly shows its limitations with high-voltage high-frequency measurements. Making a compensation network that doesn't dissipate much power at fairly high currents is probably not trivial. If you want to measure hundreds of volts at hundreds of MHz, you probably need to spend a bit more.