New Low Cost Rogowski Current Probe by Micsig RCP500

[@eeengineer8851]

Rogowski coils... Been using those at work for well over a decade now. We have some at the lab at work good for >2kA (!)... Very useful to test overcurrent and short circuit detection functions. We design some EV type inverters running on 700VDC so 480VAC to the motors. One nice feature on these is the ability to snake them around a device lead (in the smaller ones) to get the AC current in a fet or similar. Right now a project I am working on there is some testing where 100+ A peak fault currents are an issue to look at.

[@john_hind]

Had to Google 'Rogowski' to see how this works! Very cleaver, the closure makes neither an electrical nor a magnetic circuit, it is just to ensure the circumferentially wound coil completely encircles the current bearer! Would be interesting to see how this compares with a typical hall effect clamp probe. Also, what happens if you wrap the Rogowski coil twice around the bearer?

[@KissAnalog]

Thanks John! You again bring up some very interesting ideas!

[@versace885]

HI Eddie, I really appreciate your review. It is nice to get all the info you can. Thank you for this video.

[@KissAnalog]

Thanks so much!

[@michelLevisse]

Thank you for this probe review.

[@KissAnalog]

You bet! Thanks for your feedback!

[@brianst.pierre6566]

Hi Eddie, after watching the completely dodgy way you hooked up to your Variac, I just wanted to recommend the Quicktest mains connector test block. I saw Big Clive using one and got one for 120vac myself. Much safer to get mains to your projects. Sets a good example.

[@hoobsgroove]

Nice maybe should get them to make one of your own design be cool!! I was thinking a portable power supply with metre nothing anything like that?

[@ExPsy]

That Tektronix oscilloscope has isolation, external trigger, and is quite portable while being cat rated. Why do you want to get rid of it? I have an older version here in a quite bad shape and still plan to service and repair it in order to check some tricky high voltage/current circuits.

[@H-77]

I'm surprised to see the bandwidth that low, given that it's a Rogowski I would have hoped for something a good deal faster than that.

[@KissAnalog]

Thanks! I think it is pretty darn good for the cost, but now you make me want to test it to see how fast it rolls off. Maybe it is a soft roll off and gives good measurements out to a higher freq?

[@H-77]

@@KissAnalog I'd be interested to see - I also haven't had a chance to look at the datasheet for this, so I may be premature in dismissing its high-frequency performance. Fast isolated current measurement has always been a problem, and there's no magic bullet. Hall effect is accurate and has DC response, but is only good to a few hundred kHz. Current transformers can be extremely fast, but they don't do really low frequencies well. The good Tektronix current probes use a combination of the two - hall effect for DC, and a current transformer for high frequencies. It's hard to complain too much about this thing though, since it costs about five percent as much as a Tek current probe.

[@KissAnalog]

I'll do a video and give a good review of these new probes and compare to my Tek.

[@frankbeckman2663]

Darn KZbin's just make me spend money, especially with a $20 coupon. I notice some 1/f noise on looking at small currents, is this normal?

[@jamesking7868]

its a pity is not x10/x100 switchable and 200mA minimum current is quite insensitive and no DC measuring support. The Micsig CP2100A is a bit less than twice the price, is x100/x10 switchable, 50mA minimum current AND has DC current measurement and a far wider bandwidth DC-800Khz bandwidth... but does not have the flexible Rogowski current loop. On the plus side Micsig is a real company with actual published specs and available instruction manuals. Many of their probes even have indicative frequency response graphs. I have a Micsig DP10007 differential probe and am quite happy with it, especially for the price if you want more sensitivity there is the GMC-I prosys cp-35. its x10 only and has a limited bandwidth of dc-100Khz (-0.5db at 100Khz) but goes down to 5mA and has published specs, downloadable manual and indicative frequency response chart. I own one and it works well. I got mine on special offer for £220 including taxes from alpha electronics in the uk. Full price is quite steep - ~ £500 including taxes from radio spares... unfortunately the ability to measure low mA costs more £. However multiple companies rebadge it so if you look around you can sometimes find it at not crazy prices.

[@BjornV78]

If the wire you want to measure is flexible, you can place 2 turns through the current coil, that will double the output and lower the minimum current that can be measured to 100mA. With 10 turns, you can measure down to 10mA. Grtz

[@KissAnalog]

Thanks for your feedback! I have shown in other videos how to measure current either higher or lower than the rated current of a current probe, but I think its time to do some shorter videos on how to use the current probes to get the most out of them.

[@jstro-hobbytech]

Forgetting something......

[@KissAnalog]

Dude - you are the best!! Thanks so much!

[@fredflintstone8048]

Eddie. you're going to need a bigger bench. Just a suggestion, a point to keep in mind. I appreciate all you present, but one produces what they produce, deliver what they deliver, and promises are meaningless on youtube. In fact they get a bit old.

[@jstro-hobbytech]

Could I be proof the patreon comment is false???? Hahaha jk

[@KissAnalog]

U funny guy Joey;)

[@nickayivor8432]

My Mentor Kiss Anulog 👍 ACCOMPLISHED KISS ANULOG from Nick Ayivor from London England UK 🇬🇧

[@KissAnalog]

Thank you!!

[@ronvinsant9863]

300kHz? Not very useful in power supply work..

[@hoobsgroove]

What power supplies are you using that uses more than 300 kilohertz and for what purpose?

[@H-77]

@@hoobsgroove The switching frequency might only be 100 kHz, but that doesn't mean that you don't have signals a whole lot faster. It's very useful to be able to see higher frequency harmonics, ringing, etc. Also, the current rise time can be extremely fast, sometimes pushing well into the MHz region, especially during fault conditions.

[@ronvinsant9863]

@@hoobsgroove snubber ringing, GaN running at 1MHz, GaN risetimes at 700ps, even 300 to 500kHz switching in multiphase server applications..

[@KissAnalog]

It is true - the rising edges result in much higher freqs, but then maybe this goes higher but just loses acuracy. I'll give it a real world test in another video where we will look at a switching Power supply.

[@KissAnalog]

It is true - most Power Supplies probably switch less than 200kHz.