Micsig Current Probe CP2100A/B Tests and Comparing

[Martin72]

Hi,

https://www.eevblog.com/forum/testgear/350mhz-scope-2020/msg3056674/#msg3056674

I decided to order one, take it to work and hopefully can directly compare to other probes we use.
100Apk, 2.5Mhz Bandwith….sounds nice.

Price is 375€ (Batronix), well, what do we get from others:

Rigol RP1002C for 1886€

Testec TT-CC990 for 1178€

R&S RT-ZC02 for 898€

Siglent CP4070A for 842€

None of them offers the claimed 2.5 Mhz bandwith, some offer more than 100Apk, some less.
But all got one thing in common:
They were unlikely more expensive.
Therefore, the Micsig is very interesting.
The Micsig, like all other I´ve linked didn´t got a degaussing function, like I know from our tektronix probes but also from the lecroy ap011 probe.
At home I got the Owon CP05+ Probe, for appx 190€ incl. VAT.
Well....hm....Ah, forget it, this thing is crap.
Bandwith is claimed by 200khz, in real it would be something around 100khz, very noisy, you could use this thing from 1A up.
Before I got the Hantek CC-65 Probe....God...

For it´s price, I expect the Micsig will do a better job than my Owon or Hantek, that´s for sure.
But what about to compare it with "state of the art" probes?
What we got on work are Tektronix Probes and Lecroy Probe.
Chances are given, I can compare the Micsig with them, if Time allows it.
So I would do a comparison between CP2100B, CP05+, A6302, A6303, AP011.

My greatest "fear" would be the noise level.
Using tek probes or the ap011 from lecroy, you have a really low noiselevel - Could the CP2100B have it too ?

Let´s find it out...
Missing degaussing function doesn´t concern me much, more important is the noise.

But first of all, I´ll send a offer request to batronix, it would be 3% off I guess.
But hey, taking all what you can get..

Nevertheless, the probe should arrive within the forthcoming week.

Any test suggestions ? Post it here.
DC current is self explaining, so no worries.
AC current I could measure up to 400hz.
Switching power current upt to say 10...20khz, depending on the DUT I could get on work.

To be continued..

[Martin72]

But first of all, I´ll send a offer request to batronix, it would be 3% off I guess.
But hey, taking all what you can get..

No discount at all, but it doesn´t worry me.
When it´s good, then it´s got excellent bang for bucks value(see first post).
If it fails (noise..), I´ll return it and got my money back.
Should arrive in 2 days...

[2N3055]

But first of all, I´ll send a offer request to batronix, it would be 3% off I guess.
But hey, taking all what you can get..

No discount at all, but it doesn´t worry me.
When it´s good, then it´s got excellent bang for bucks value(see first post).
If it fails (noise..), I´ll return it and got my money back.
Should arrive in 2 days...

Looking forward to see how it fares. Thank you for the effort.
For low level testing, few loops of wire and serial 50 Ohm on a signal generator could give interesting signal to see how it behaves down in noise land....

[Martin72]

Good idea 

[Martin72]

At last, I´ve found some specs for the lecroy ap011 which I want to compare with the micsig - from an old, downloadable catalogue.
(Would upload here because of some interesting articles inside, but it´s too big)
From the spec side, the ap011 looks ( of course ? ) better what accuracy concerns.
But I won´t know the original price for this…
Got the Information from DHL, the probe should arrive on wednesday.
First I will do some tests here at home, like 2N3055 suggest one, together with the owon probe.
After this, I want to take the both to work and trying to find something interesting to measure and compare.

[Martin72]

Got the Information from DHL, the probe should arrive on wednesday.

No….Today. 

First impressions, good building quality, clamp got not a gap between when it´s closed ( like the owon did..), very solid cable, not bad.
Maybe tomorrow I start some measurings or at the forthcoming weekend.

[TurboTom]

Have you got an option to evaluate the inductance of the probe? @100A, even a few nanohenries can be a lot. If too high, this may limit the usefulness of the bandwidth at the high current range.

[Martin72]

Hi, I´m afraid not.
But have a look at the specs.

[nctnico]

At high currents you can compare a shunt resistor versus the probe. You just need a way to send a large current surge.

[Martin72]

Shunts we got a lot, we got also ZES LMG power analyzers with high precision current transformers or internal shunts.
For a surge current, I think I could use our selfbuild inductance meter.
It was designed to measure filter coils nearly to their normal operating current.
We calculating the inductance through the voltage-time area via pulses send from an µC to a IGBT.

[Martin72]

First time playing around with it, some simple DC measures..
To get a higher current measure, 4mm banana cable was turning five times through the probe, power supply deliever 3A max.
Really nice: On the siglent you could choose between voltage or ampere in the channel menu, then the probe ratio will also changed from 1:10 etc. to V/A, makes it easy to find the right range.

Noiselevel….
Picture shows the noiselevel at 50mA/Div, for me it´s acceptable and a nice surprise.
Channel 4 shows the noiselevel from the owon probe....
Current was measured by my calibrated brymen bm869s.
At 10A the micisg beeps a warning and the 10A button is flashing, reminding you to change to 100A, nice.
This was the first play around, more to come soon..

[maginnovision]

I was hoping to add some extra probes to the mix but my bnc adapters are VERY noisy. A short across them had more noise than the owon. I suspect the ground is making poor/no connection since they're all safety adapters so you I don't die.

Looks good so far. The owon looks like it'd work much better for a dmm.

[Martin72]

I think the same about the owon.
Nearly a year ago, I had a thread started about it, doing a schematic from it.
It got a very simple circuit design and the claimed 200khz bandwith couldn´t be right.
Nevertheless, the "Noisetest" was positive, so I will take the micsig to work instead of returning to batronix.
What I will do there is a comparison between lecroy ap011 and, maybe a little unfair, to the good old tek probe.
Next time ac currents will be measured, also I try to measure the bandwith/risetime.
If I get the chance, I´ll do some measures on "real" DUTs ( we are in the market of building power inverters up to 200KVA, 50/60/400hz, switching frequencies between 1.62....20khz)
Tomorrow I´ll try 2N3055´s suggestion.

Edit:

What else I want to try is using a power bank instead supplying the probe  from a USB port, to see if the (actually low) noise level could be further decreased with it.

[Martin72]

Did it..

Using the nice bnc-adaptors, I took the internal generator as source and the "load" was the internal 50ohm Input, then turning 10 wires through the clamp.
Below some measurings like risetime, several sinewave frequencies and....If I got bode plot on board, why not use it...So I´ve done it.
The testsetup especially with the 10 windings could not be perfect but at last, I´m surprised about the micsig in a very positive way.
Next step, comparing at work….
Martin

edit must measure the risetime again, wrong channel...

risetime added

[2N3055]

That is decent small signal response, and noise is quite low..  Nice work Martin! Looking forward to next episode!

[voltsandjolts]

Micsig has been a pleasant surprise for me too.
I've bought two of their tablet scopes, best portable scope for the money IMHO.
Will be interested in your test results.

[Martin72]

Next week is a short one due public holiday on thursday, so I have three days to "steal" a little bit time and some gear..
Goals are the mentioned comparison between tektronix 50Mhz clamp and the lecroy what accuracy, risetime/bandwith concerns.
Also I want to measure "real" high current and not turning windings through the clamp.
Well, we´ll see what happen.

[tautech]

Martin, in this screenshot there appears some significant current probe propagation delay:



Can you use the channel 1 deskew to see how much delay the MICSIG current probe inserts into the measurements ?
Does it meet the manufacturers propagation delay spec ?

[Martin72]

Hi,

Will do it in the next days.

Martin

[Martin72]

Comparing three probes noiselevel at 50mA/div. on the hdo6043a, Tektronix, Lecroy and Micsig.
"Of course" the Micsig is noisier, but not much - Excellent.
@tautech: Probe is at work, will looking for, if the lecroy got the deskew function too.

[tautech]

@tautech: Probe is at work, will looking for, if the lecroy got the deskew function too.

All half decent scopes have channel deskew. 

SDS5054X SDS5104X with 3 current probes....ch1 probe broken 
Ch2 menu showing deskew WRT the ch4 voltage probe.

[Martin72]

All half decent scopes have channel deskew.

Never used this, so I must look at it. 

[2N3055]

All half decent scopes have channel deskew.

Never used this, so I must look at it. 

It's in Channel setup, in preprocessing, on the right..

[Martin72]

Next week is a short one due public holiday on thursday, so I have three days to "steal" a little bit time and some gear..
Goals are the mentioned comparison between tektronix 50Mhz clamp and the lecroy what accuracy, risetime/bandwith concerns.
Also I want to measure "real" high current and not turning windings through the clamp.
Well, we´ll see what happen.

Unfortunately, I got no time at work this week - Except this one..
"Real" DC current measure up 100A.
The tek probe was in use, so I compare it with the lecroy ap011.
"reference" was a shunt, voltage measured by fluke 87V in hires mode, scope was a lecroy hdo6034a.
Source was a 100adc supply in constant current mode.
The cp2100b was every time in it´s tolerance values, also the ap011 - Remarkable: The claimed 15% from 40A up wasn´t reached at any time, worsest deviation was 4.22% at 100A.
Nice..
Hopefully, AC measure and switching current measure I could make next week on work.
I´ve took it back to home, making the measure tautech asked for it.

[Martin72]

Can you use the channel 1 deskew to see how much delay the MICSIG current probe inserts into the measurements ?
Does it meet the manufacturers propagation delay spec ?

Hi,

Specs were <150ns (10A), <200ns (100A).

Below 2 pics without deskew and with max deskew on ch1.

[tautech]

Here from Martin's screenshot we see some small offset with the MICSIG current probe WRT the voltage probe. Negative pulse inaccuracy ? 



Also Deskew is not set correctly as the rising edge of the current should match the voltage rising edge better.
If both channels are set on 0V as these are and both similar amplitude the trigger needs be set to 50% and at that point the deskew adjusted so both signals cross through the trigger point at exactly the same instant. ps accuracy is possible. 

For most measurement needs channel deskew does not matter very much but for accurates results from Power analysis it does. Practice makes perfect. 

Oh and another trick when one trace is less noisy than the other.....select it so it overlays the noisy trace and they both become visible. 

[Martin72]

Also Deskew is not set correctly

As I said, I never used this before so any "hints" like yours are welcome. 

[Martin72]

Negative pulse inaccuracy ?

No, forget to press "zero" before...   

[2N3055]

Also Deskew is not set correctly

As I said, I never used this before so any "hints" like yours are welcome. 

Well, what is maximum deskew  time on SDS2000+ ? 
On KS MSOX3000T it is ± 100ns...  So on KS MSOX3000T  you have to deskew current probe channel for max 100 ns , and then deskew rest of the channels in opposite direction (but all for same value to be in phase) to achieve delta of 170ns..

[Martin72]

Maximum is +/- 100ns.

So on KS MSOX3000T  you have to deskew current probe channel for max 100 ns , and then deskew rest of the channels in opposite direction (but all for same value to be in phase)

As I did the measurements, I also did one where both channels were deskewed to the max 100ns:

[tautech]

Negative pulse inaccuracy ?

No, forget to press "zero" before...   

(Attachment Link)

OK on this one ch3 is the current probe and trigger so now ch4 needs deskew adjusted to have it also at the 0s, 0V trigger crossing position. For really fine adjustments increase the timebase as required. 

[tautech]

As some example of propagation delays and the need for channel deskew to align edges for precise measurements here is 100 KHz squarewave connected to ch4 via BNC and ch3 via its 10x probe and a Tek P6021 current probe measuring the squarewave current into a 50 Ohm load.
Please disregard ringing from this setup as it's not relevant to the deskew discussion.
SDS5104X, source SDG6022X




Triggering is on ch4 @ 50% and all channels are aligned to some graticule and amplitudes adjusted so that any propagation delays are plain so deskew can be performed on channels 2 and 3 to align the rising edge 50% point and the required amount is shown in deskew and cursor measurements.



Cursors left at their settings but deskew adjustments for channels 2 and 3 entered so 50% points all cross 0V close together in time.

[maginnovision]

Does the 5k also have the 100ns limit for deskew?

[tautech]

Does the 5k also have the 100ns limit for deskew?

+100ns
So we'd select neither our fastest or slowest propagation channel but a midrange channel to trigger on and set deskew to line them all in time.
The difference between these 2 channels is ~7ns but each channel has been set to max and min deskew as an example.

[Martin72]

Today I take it to work for further testing, on the desk the lecroy hdo6034a.
And yes it got deskew also (  ), the adjustable range is +/- 990µs - WTF....

[maginnovision]

That's what I call deskew. I was a little disappointed with the ±500ns but if ±100ns is standard then I guess I'm happy with it.

[Martin72]

I wish I had 500ns...
Although I think, 100ns are "enough" for compensating e.g different cable-lenghts.
Fortunately, I got a Power Inverter for testing for a few days.
It´s understood I want to test something with the Micsig, DC-Currents I´ve already done, so I can test with the Inverter AC-Currents up to 100A/400hz.
Further pwm power current with a frequency of 10khz.
I´m looking forward the micsig will do a good job on this also.

[Martin72]

Update:

I send the micsig back to batronix for an exchange, reason:
Specsheet stated a delay under 150ns in 10A range, mine got an averaging delay of 170ns - Told them, they did a measure with another one and it was 125ns, so they offer me to exchange mine.
So AC current tests and my final verdict about will be delayed until I got the other one. 

[maginnovision]

Let's hope the next one really is in spec! So perhaps they won't always meet all specs which is a bit disappointing.

[Martin72]

Well...
If they hadn´t offered me the exchange, it wouldn´t be such a big showstopper for me.
The much more expensive examples I´ve linked in the first post do not even give this value in their specs - Maybe for a good reason...

[Martin72]

The much more expensive examples I´ve linked in the first post do not even give this value in their specs - Maybe for a good reason..

The AP011 from lecroy for example...measure it today on work, appx 338ns delay.
So I don´t bother about 170ns, especially since you will use deskewing when taking power measurements.
New probe doesn´t have arrive yet, as batronix got no more on stock and offer me to return my former one to me plus the money, until they have new (and checked before) in stock.
I´ve agreed to it, as I want to make further measures asap to close the "case", giving a final verdict. 

[Martin72]

Little update:
New  (selected) probe should arrive in the next week.
"Unfortunately", I have three weeks' vacation then, couldn´t do AC tests...
What I likely want to do is a comparison to more expensive models, using the same measurement principle like the micsig.
Are they better, equal or even worser than the micsig...
Ask batronix for loan me for example this one for comparing:

https://www.batronix.com/versand/messtechnik/tastkoepfe/Testec-TT-CC-770.html

Or this one:

https://www.batronix.com/versand/messtechnik/tastkoepfe/Rigol-RP1002C.html

They answered, directly no, but I could "buy" it and send it return after a week....Hm-hm..

Comparing with the owon cp-05+ I got here, was no compare, the micsig are ways better in every case.

[Martin72]

Update, the second.

Still got no new probe as they aren´t arrived to batronix.
Now I got a problem, in ebay there was an offer I could not longer withstand it and asked for the last price.
A used combo of tektronix A6302 and mainframe/amplifier.
If I could get it to nearly the price of the micsig, I´ll buy this, sorry.
And the last verdict will be therefore my final:

- Surprisingly low noise
- Accuracy always in the specs
- For it´s price, I think you´ll never get a better one, even if they would cost double or more ( because of the measuring principle - only currentcompensating models should be better in accuracy, these ones you won´t find under 3k€)

If I don´t get the tek, I´ll continue testing.

Martin

[Martin72]

Update, the third...

Couldn´t get the tek probe, therefore looking further to get the micsig back.
It´s still out of stock - But the cp2100A with "only" 800khz bandwith are in stock and therefore I´ve order one now.
Let´s see if this perform as well as the B version - If yes, it would be the best bang for bucks, as it only costs 180€ (excl. VAT)....
Should arrive inbetween this week.
Martin

[Elasia]

Update, the third...

Couldn´t get the tek probe, therefore looking further to get the micsig back.
It´s still out of stock - But the cp2100A with "only" 800khz bandwith are in stock and therefore I´ve order one now.
Let´s see if this perform as well as the B version - If yes, it would be the best bang for bucks, as it only costs 180€ (excl. VAT)....
Should arrive inbetween this week.
Martin

Always in stock if you are willing to wait on the boat lol.. lowest i've seen for the B is $360 usd or so

I'd think they would be very similar just the 3db point is 0.8 MHz vs 2.5 MHz

Saw a recent review here of the B as well

[Martin72]

Wtf, Metalica ?! 

[Martin72]

Nice little review..
The cp2100A does arrive tomorrow 
Batronix are fast as lightening.
And as it was on it´s way, another guy from them mailed me, ah yes, today we got the cp2100B on stock...Thank you.
But first I want test the A model, if I don´t find any disadvantages against the B except the bandwith, I think it could stay here.

[Martin72]

Tadaa, it´s arrived...

Looks, smells, feels the same, the clamp itself was 100% the same as on the "B" version.
Makes me curious to know what´s inside the box....
And at last I could test switching frequency - I got my deskew fixture....
Tests will follow.

Martin

[Martin72]

And at last I could test switching frequency - I got my deskew fixture....

 

Small loop I could try to dremel a bit, large loop no chance I guess.

[2N3055]

And at last I could test switching frequency - I got my deskew fixture....

(Attachment Link)

(Attachment Link)

 

Small loop I could try to dremel a bit, large loop no chance I guess.

OMG that sucks...

I guess we should press on with a design that is more universal...
If only my day had 48 hours...

[Martin72]

Got got my thoughts on it too, taking the large loop circuit as the basic for it, instead of the loops on the pcb taking a 2-pole connector like steve suggested, fixed frequency but gate-resistor can be switchable .

[Elasia]

You can dremmel the large loop as well but you have to go right to the edge of the copper

I'll eventually cnc mill mine down for use with my micsig on the large loop because its so close

[Martin72]

Done it and it works.
Needs some fine polishing, but this could wait...

[Martin72]

Micsig on the deskew fixture, 22Khz, 147mA, 1A

Not bad... ( choose averaging in the 50mA range)

Will do the same "home tests" like with the B version, finally a high current test next week when I´m back to work.
But hey, in my opinion, besides the lower bandwith, it´s equal to the c2100b and therefore a real good deal.
To be continued

[tautech]

And at last I could test switching frequency - I got my deskew fixture....

(Attachment Link)

(Attachment Link)

 

Small loop I could try to dremel a bit, large loop no chance I guess.

OMG that sucks...

I guess we should press on with a design that is more universal...
If only my day had 48 hours...

Fix for the single 147mA loop as below:

[Martin72]

Got the CP2100A at work, same results as the B version.
So if you could be happy with 800Khz bandwith, take this one and save lots of money.
Comparing to the rest who will "give" us 800Khz or less, the price is outstanding.
But I send it back, because the "B"s are on stock again and I want the 2.5Mhz....

Final Verdict...

Pros:

- Always in their specs what accuracy concerns
- Really good building quality, wants me to make a teardown
- Small clamp
- Outstanding bandwith for the price, 800Khz for 200, 2.5Mhz for 375 Bucks - You won´t find this anywhere.
- Good, not best, but really good low noise level for it´s range
- Offset could be manually compensating (up/down additional to the auto-zero function)

Cons:

- Small clamp, but a little "thick" for lower current measure (probably you must do some extensions to put the clamp onto it for measuring)
- Needs external power supply
- Accuracy always in the specs but it´s somewhere around 4..5%, others could do it better (but cost much more)
- No degaussing function ( but this you will find only on models starting from 3000 bucks )

This or nothing...
Either you spend 200/370 Bucks for them or you save your money until you can afford the hioki things under several brands, starting with 3K bucks and upwards.
You shouldn´t expect the less noise and precision like you perhaps know from tek probes.
It is usable with currents starting from 50mA/div.
If this fits your needs, buy it.
You musn´t spend more money.
Really good stuff !

[Martin72]

Batronix...Sometimes I think, they´re right aorund the next corner in my neighbourhood...



Luckywise, I must do some power tests in the next two weeks at work. I´ll "smuggle" the probe and take some "real" measurings in ac and dc, full current (instead of turning loops).
Also, the question pops up of how it handles high dc-current, if it gets magnetized after this - This I´ll test also.
For the forthcoming weekend I´ll test it on my fixture, expecting "sharper" waveforms as the cp2100a.
And still I´m very curious about the inside...but couldn´t find a point to open it without getting schratches - No screws in sight.

[Elasia]

Batronix...Sometimes I think, they´re right aorund the next corner in my neighbourhood...

(Attachment Link)

Luckywise, I must do some power tests in the next two weeks at work. I´ll "smuggle" the probe and take some "real" measurings in ac and dc, full current (instead of turning loops).
Also, the question pops up of how it handles high dc-current, if it gets magnetized after this - This I´ll test also.
For the forthcoming weekend I´ll test it on my fixture, expecting "sharper" waveforms as the cp2100a.
And still I´m very curious about the inside...but couldn´t find a point to open it without getting schratches - No screws in sight.

I'll look at mine later and see about poping it, i also just got a new microscope with a 4k camera so maybe i'll post some high res pics

[dcac]

I would certainly be interested in seeing whats inside. 

[Elasia]

After removing the front facing sticker with my heat gun.. i made it inside, rather impressed with the build quality

sadly most of the goods between the current clamp and the cable going to the scope are hidden inside metal cans...   i will attack it further tomorrow and see about poping them off

[dcac]

Yeah I notice the good build quality on their Differential probes too from looking at teardown videos. It's an annoying habit placing the screws under the label though - but better than welding it shut I suppose.   

Can you determine how many leads goes to the 'clamp head' - there might be an amplifier in that too.

But please don't take anything apart that's not easily coming back together again on my part.

[Elasia]

Some pics.. not 4K, forgot to get wide view lenses for the camera lol, maybe i'll add some monday

Edit: dumb forum picture bug strikes again

[Elasia]

nt

[Martin72]

When I think about the owon crap, which costs only  40..50 bucks less than the 2100A....Boy what a difference.

[Elasia]

When I think about the owon crap, which costs only  40..50 bucks less than the 2100A....Boy what a difference.

No kidding right?  The clamp im too lazy to take apart.. ended up needing to use it so put it all back together lol

Just look how well curved that line is... not one bit of ringing, nothing to exciting just a 200Hz pwm for a coil

[dcac]

This is obviously a completely different class than my toyish CC-65. It might be time to upgrade.

[Martin72]

Some pics..

It bothers me that I´ve send the a version back, would be interesting to know the difference ( same board), perhaps changing a few components will turn the a to the b..

[Elasia]

Some pics..

It bothers me that I´ve send the a version back, would be interesting to know the difference ( same board), perhaps changing a few components will turn the a to the b..

Oh you already sent it back? Yeah i was thinking that it might just be a few chip components.. all I got are Bs so no help there

[dcac]

Some pics..

It bothers me that I´ve send the a version back, would be interesting to know the difference ( same board), perhaps changing a few components will turn the a to the b..

On this PCB it says "CP2100A/B_DIG_V2X" so chances are good it's same board - but likely there's also circuitry in the clamp and that might be different.

Also couldn't find a single trimmer - so is the calibration done digitally(?)

[Elasia]

Some pics..

It bothers me that I´ve send the a version back, would be interesting to know the difference ( same board), perhaps changing a few components will turn the a to the b..

On this PCB it says "CP2100A/B_DIG_V2X" so chances are good it's same board - but likely there's also circuitry in the clamp and that might be different.

Also couldn't find a single trimmer - so is the calibration done digitally(?)

Thats some kinda micro on board so i would say so yeah

I should have got a pic of the micro.. forget what it was other than the mfg uses a bee symbol

[Martin72]

Also couldn't find a single trimmer - so is the calibration done digitally(?)

Quite interesting - Ask them for a service manual, of course, they gotn´t one..

[dcac]

Also couldn't find a single trimmer - so is the calibration done digitally(?)

Quite interesting - Ask them for a service manual, of course, they gotn´t one..

oh, if it was easy getting service manuals we wouldn’t need all the reverse engineering fun. 

[Sighound36]

Some good work here chaps 

Can I make a suggestion here when you guys do any form of RE. Why not four of five of you club together and split the cost of the purchase, that way you have a two fold benefit. You do not pay the full price (after discount) plus you can do as you like with the equipment. Just a thought 

I would be happy to contribute if you were to go down this route.

[Elasia]

Not a bad idea really.. I think Martin and I are exceptions to that in that we mostly RE our daily drivers we use for work.. I always want to know whats inside of whatever I'm using

I'd entertain RE teardowns like that if it wasnt for the zoo of projects I already got... if I add more my wife would murder me haha

[bicycleguy]

When I think about the owon crap, which costs only  40..50 bucks less than the 2100A....Boy what a difference.

No kidding right?  The clamp im too lazy to take apart.. ended up needing to use it so put it all back together lol

Just look how well curved that line is... not one bit of ringing, nothing to exciting just a 200Hz pwm for a coil

Trying to justify one of these for myself so trying to understand.  A few questions:
1.  Wouldn't you need to look at a much higher scope frequency to see any ringing?
2.  On a typical solar inverter or SMPS would there typically be any place that large a probe would fit that would be worth while to see ringing?

[Elasia]

Trying to justify one of these for myself so trying to understand.  A few questions:
1.  Wouldn't you need to look at a much higher scope frequency to see any ringing?
2.  On a typical solar inverter or SMPS would there typically be any place that large a probe would fit that would be worth while to see ringing?

That specifically was a dig at the CP-65 and clones of it.. yeah.. it rings at that low of a frequency x_x

I'd point you to watch this guy's review of it.. and yeah he kinda looks like he came from metallica lol

[bicycleguy]

Is there going to be a CP2100A vs CP2100B comparison?

[Martin72]

When somebody else will buy a cp2100a, why not.
To be honest, I´ve played with the thoughts, buying the 2100a again and compare it to the b version.
Or trying to tear it down, especially the clamp, because there must be "more electronics" in it.
You can hear a relay switching, also the ammount of the leads coming from the clamp part are too less - Something must happen in the clamp part before...
Boy, imagine, this thing costs only 200/350 bucks...

[Elasia]

When somebody else will buy a cp2100a, why not.
To be honest, I´ve played with the thoughts, buying the 2100a again and compare it to the b version.
Or trying to tear it down, especially the clamp, because there must be "more electronics" in it.
You can hear a relay switching, also the ammount of the leads coming from the clamp part are too less - Something must happen in the clamp part before...
Boy, imagine, this thing costs only 200/350 bucks...

Yeah there are more inside the clamp, notice the clamp gets both positive and negative power supplied to it... all those little wires are on top of the main signal wire that is shielded itself

It's more of an active probe head unit... pretty amazing for the cost, they should come out with active scope probes too if they can make them anything like their diff and current probes

[EEVblog]

Heads up, I'm going to sell the 2MHz unit and I just got stock
Need to do a video of course, but will be offering a deal to my newsletter subscribers and Patrons and forum supporters shortly.
Should be able to beat other prices but that probably depends on your country.
Price will rise once my stock is gone, as MicSig gave me a deal on the batch of units.

[EEVblog]

Yeah there are more inside the clamp, notice the clamp gets both positive and negative power supplied to it... all those little wires are on top of the main signal wire that is shielded itself
It's more of an active probe head unit... pretty amazing for the cost, they should come out with active scope probes too if they can make them anything like their diff and current probes

Yes, I will be able to post a photo inside the clamp head tomorrow, it is indeed an active head design.

[Elasia]

Heads up, I'm going to sell the 2MHz unit and I just got stock
Need to do a video of course, but will be offering a deal to my newsletter subscribers and Patrons and forum supporters shortly.
Should be able to beat other prices but that probably depends on your country.
Price will rise once my stock is gone, as MicSig gave me a deal on the batch of units.

Wow nice

Branded?  I could always use another, i'll take one off your hands

Cant wait to see inside that probe head

[EEVblog]

Branded?

No, not yet, it was a very significant cost to do that. Possibly in the future.

[Martin72]

Yes, I will be able to post a photo inside the clamp head tomorrow, it is indeed an active head design.

Wtf, how could they do it for this price....
Remember, I´ve bought an owon cp-05+ clamp for 170 bucks...
It looses in every case and cost only 30 less.

[EEVblog]

Full album here:
https://www.flickr.com/photos/eevblog/albums/72157715635511053

Uses an AD8421 inamp on the front end with dual hall effect sensors and relay switching.

Micsig CP2100B Current Probe Teardown by Dave Jones, on Flickr

[EEVblog]

Yes, I will be able to post a photo inside the clamp head tomorrow, it is indeed an active head design.

Wtf, how could they do it for this price....
Remember, I´ve bought an owon cp-05+ clamp for 170 bucks...
It looses in every case and cost only 30 less.

Yikes. No contest!
I can offer the 2MHz CP2100B for US$365, MicSig sell it for US$499 on Aliexpress and US$599 on Amazon. Got them in stock now. Going to add them to my store today.
Not sure if I'll bother to carry the CP2100A model?
BTW, this design was supposed to be 2.5MHz, and I have an early unit labels that. But they couldn't maintain this spec in production so dropped it to 2MHz.

[Kean]

I can offer the 2MHz CP2100B for US$365, MicSig sell it for US$499 on Aliexpress and US$599 on Amazon. Got them in stock now. Going to add them to my store today.

My credit card is ready when you are!
I was about to buy one the other day on the AliExpress "Micsig official store", but the price was just a little too painful so I put it off again.

[maginnovision]

Nice! Waiting on a link now.

[Elasia]

Yes, I will be able to post a photo inside the clamp head tomorrow, it is indeed an active head design.

Wtf, how could they do it for this price....
Remember, I´ve bought an owon cp-05+ clamp for 170 bucks...
It looses in every case and cost only 30 less.

Yikes. No contest!
I can offer the 2MHz CP2100B for US$365, MicSig sell it for US$499 on Aliexpress and US$599 on Amazon. Got them in stock now. Going to add them to my store today.
Not sure if I'll bother to carry the CP2100A model?
BTW, this design was supposed to be 2.5MHz, and I have an early unit labels that. But they couldn't maintain this spec in production so dropped it to 2MHz.

I was wondering what the deal was with that 2 vs 2.5 floating around

Mine are all labeled as 2.5 on the control box, did they change that to 2? Or is it they call all of them actually to be 2 MHz and ignore the label?  What are your units labeled as?

Cool shots at the probe head, was wondering if they had any tuning parts inside it and how well the sensing halls were shielded

Interesting price point too, thats about the same as the best deal i saw on them.  Picked one off the bay for 360 direct from shenzhen maybe a month ago.. was expecting a boat but the guy dhl expressed it which was pretty cool, he has sense raised his price to 400

[Kean]

There are some on AliExpress at a much lower price than the official store, but I just wasn't willing to risk getting a factory second.

[EEVblog]

It's on the store:
https://www.eevblog.com/product/cp2100b/

[EEVblog]

I was wondering what the deal was with that 2 vs 2.5 floating around
Mine are all labeled as 2.5 on the control box, did they change that to 2? Or is it they call all of them actually to be 2 MHz and ignore the label?  What are your units labeled as?

My stock units are labeled 2MHz.

[maginnovision]

Ordered.

[EEVblog]

There are some on AliExpress at a much lower price than the official store, but I just wasn't willing to risk getting a factory second.

I can beat those Aliexpress prices, at least for the first batch of units.

[Kean]

Ordered.

ditto - I'm in Australia so my Internet sucks!

[EEVblog]

FYI, have just sent the link to my newsletter list of 10,000 people and Patreon, so the 50 units might not last long.

[technogeeky]

I got one, declined card, paid with paypal, then it said it didn't go through, then finally it said the order is processing so I can't submit it.

Hope for the best!

[maginnovision]

FYI, have just sent the link to my newsletter list of 10,000 people and Patreon, so the 50 units might not last long.

I don't think I've ever received the newsletter despite subscribing.

[TheDefpom]

FYI, have just sent the link to my newsletter list of 10,000 people and Patreon, so the 50 units might not last long.

I got the newsletter email.... just not the money to get one :-(

[Elasia]

Ordered, i'll be interested to compare it to my 2.5 ones

[Elasia]

Down to 45 units already

[EEVblog]

I got one, declined card, paid with paypal, then it said it didn't go through, then finally it said the order is processing so I can't submit it.
Hope for the best!

I have a new Stripe credit card option, a couple of cards have failed since I started it, no idea why, that's a Stripe thing.
There are no pending orders, so yours must be in there.

[Cubdriver]

38 left.   

-Pat

[kahuna0k]

Got one, paid with Sripe and the transaction went through without problems (Mastercard). By the way I paid with Stripe because I suppose that the fees are better than PayPal, is that true? What payment method should we choose to maximize your profit?

[EEVblog]

Got one, paid with Sripe and the transaction went through without problems (Mastercard). By the way I paid with Stripe because I suppose that the fees are better than PayPal, is that true? What payment method should we choose to maximize your profit?

PayPal is 2.4%, stripe is 3.2%. I just offer both for convenience.

[Serpent10i]

The stripe USD to AUD conversion was more favorable for me. 535.38 AUD turned into 400 USD to for paypal and but only 385 USD with stripe(and Visa). I didn't know their fees were higher

[Elasia]

The stripe USD to AUD conversion was more favorable for me. 535.38 AUD turned into 400 USD to for paypal and but only 385 USD with stripe(and Visa). I didn't know their fees were higher

Stripe apparently uses the forex spot price.. PayPal wants a foreign transaction fee

[Elasia]

Got one, paid with Sripe and the transaction went through without problems (Mastercard). By the way I paid with Stripe because I suppose that the fees are better than PayPal, is that true? What payment method should we choose to maximize your profit?

PayPal is 2.4%, stripe is 3.2%. I just offer both for convenience.

International paypal?

https://www.ebayfeescalculator.com/au-paypal-calculator/

has it at 3.6

[EEVblog]

The stripe USD to AUD conversion was more favorable for me. 535.38 AUD turned into 400 USD to for paypal and but only 385 USD with stripe(and Visa). I didn't know their fees were higher

Wow, that's significant.
I buy in USD but sell in AUD for various reasons so either have to keep adjusting my prices as the exchange rate changes, or win/lose as it fluctuates. So that US$365 price in AUD equivalent is just what xe.com told me today.

[EEVblog]

PayPal is 2.4%, stripe is 3.2%. I just offer both for convenience.

International paypal?
https://www.ebayfeescalculator.com/au-paypal-calculator/
has it at 3.6

I just checked and it is 3.65%
I must be confusing it with something else.

[EEVblog]

PayPal is 2.4%, stripe is 3.2%. I just offer both for convenience.

International paypal?
https://www.ebayfeescalculator.com/au-paypal-calculator/
has it at 3.6

I just checked and it is 3.65%
I must be confusing it with something else.

Ah, 2.6% for Australia

[Kean]

I'm glad I went with the convenience option (PayPal One-Touch) then if you got an extra few bucks out of it.  I considered using Stripe as I thought it might have lower fees.

(Edit because I can't speel)

[Weston]

Are the sensors accessible to read off the part number? I don't think this probe use a hall effect sensor, hall sensors don't have the bandwidth.

They most likely use a TMR sensor made by Multi Dimension, something like this: https://www.aecsensors.com/components/com_virtuemart/shop_image/product/Magnetic-Tunnelling-Magnetoresistive-(TMR)-Linear-Sensors/pdfs/TMR2503-Datasheet-EN-V1.0.pdf

I am unsure why they use two sensors. My best guess would be that the outputs are summed to improve SNR or to reduce the impact of stray magnetic field.

Looks like the design is a basic analog front end with a microcontroller for the user interface and auto zeroing, pretty similar to the current probe I am designing based on a higher bandwidth AMR sensor.

[EEVblog]

Are the sensors accessible to read off the part number? I don't think this probe use a hall effect sensor, hall sensors don't have the bandwidth.

I think I'd have to crack it open somehow, seems glued in place.
Two 4 pin SIP packages, one marked 8877, the other one not marked, possibly mounted backwards.

[EEVblog]

The sensors

[Hydron]

Thanks for opening one up and taking the photos Dave, I'll be telling work to buy one but 99% chance they sit on it until you're sold out.

Any chance that you can check the gain that the AD8421 is running at? Should be as simple as measuring the resistance between pins 2 and 3 of the IC. I assume that the relay will change gains (hence the two trimpots) but should be easy enough to tell what the default gain is - it'll be the startup gain if the relay doesn't click on power-up, or the other one if it does.

[EEVblog]

20 sold so far.

[Elasia]

Are the sensors accessible to read off the part number? I don't think this probe use a hall effect sensor, hall sensors don't have the bandwidth.

They most likely use a TMR sensor made by Multi Dimension, something like this: https://www.aecsensors.com/components/com_virtuemart/shop_image/product/Magnetic-Tunnelling-Magnetoresistive-(TMR)-Linear-Sensors/pdfs/TMR2503-Datasheet-EN-V1.0.pdf

I am unsure why they use two sensors. My best guess would be that the outputs are summed to improve SNR or to reduce the impact of stray magnetic field.

Looks like the design is a basic analog front end with a microcontroller for the user interface and auto zeroing, pretty similar to the current probe I am designing based on a higher bandwidth AMR sensor.

wow i had no idea tmr sensors are now mass produced, thats wild... i'll have to remember this nugget now..

[Martin72]

Full album here:
https://www.flickr.com/photos/eevblog/albums/72157715635511053

Uses an AD8421 inamp on the front end with dual hall effect sensors and relay switching.

Micsig CP2100B Current Probe Teardown by Dave Jones, on Flickr

Still I can´t believe they´re so cheap to buy - Even when this clamp would costs three times more, the value for money would still be great.
Wow, just wow.

I wonder what the differences between the 800khz and 2Mhz versions are...and where.

Edit:

Not sure if I'll bother to carry the CP2100A model?

Why not, it got the same incredible quality and with appx 200 buck it would be more affordable.
Looking for other brands, you won´t find 800khz bw under 1000 bucks and more.

[technogeeky]

I got one, declined card, paid with paypal, then it said it didn't go through, then finally it said the order is processing so I can't submit it.
Hope for the best!

I have a new Stripe credit card option, a couple of cards have failed since I started it, no idea why, that's a Stripe thing.
There are no pending orders, so yours must be in there.

 

Stripe failed me, but PayPal worked a treat. Thanks Dave!

I'm excited to get my hands on something that approaches thousands of dollars of value for so much less.

[technogeeky]

18 left.

[Elasia]

Still I can´t believe they´re so cheap to buy - Even when this clamp would costs three times more, the value for money would still be great.
Wow, just wow.

I wonder what the differences between the 800khz and 2Mhz versions are...and where.

Edit:

Not sure if I'll bother to carry the CP2100A model?

Why not, it got the same incredible quality and with appx 200 buck it would be more affordable.
Looking for other brands, you won´t find 800khz bw under 1000 bucks and more.

So get that A model and take some pictures

Really though i'd 99% bet on it being just some chippies OR.. more than likely it is this.. they are binning them.  Why? Dave already said it himself.. they couldnt keep up with producing 2.5MHz rated versions... almost certainly means they were rebranding them as the lessor A model via binning.  So you are really just paying for better quality parts


Also of interest there is a little known X version that was suppose to be rated for only up to 300 kHz

[Weston]

Still I can´t believe they´re so cheap to buy - Even when this clamp would costs three times more, the value for money would still be great.
Wow, just wow.

I wonder what the differences between the 800khz and 2Mhz versions are...and where.

Edit:

Not sure if I'll bother to carry the CP2100A model?

Why not, it got the same incredible quality and with appx 200 buck it would be more affordable.
Looking for other brands, you won´t find 800khz bw under 1000 bucks and more.

So get that A model and take some pictures

Really though i'd 99% bet on it being just some chippies OR.. more than likely it is this.. they are binning them.  Why? Dave already said it himself.. they couldnt keep up with producing 2.5MHz rated versions... almost certainly means they were rebranding them as the lessor A model via binning.  So you are really just paying for better quality parts


Also of interest there is a little known X version that was suppose to be rated for only up to 300 kHz

I doubt they are binning them, this is a pretty commodity thing.

The only non-jellybean part in there is the TMR sensor, and those are a relatively mature part ( I ordered some samples off amazon for a few dollars a few months ago). If there was variance on the TMR sensor it would be pretty simple to bin them before assembly.

This device is a good deal for what is on the market right now, but the production costs are pretty low. I would not be surprised if the most expensive parts of the whole thing was the nice plastic case and the custom mechanical components. The big change is this is the first design on the market using a higher bandwidth magnetic sensor as opposed to a low bandwidth hall effect sensor used on the cheap probes, or the hybrid hall effect + current transformer used on the super expensive current probes.

[Kean]

Has anybody ever looked at the Instrance ICP5000 current probes?

They supposedly can do DC or AC to 20A with bandwidth of 25 or 50MHz.  They also make a "matching" differential probe IIP1000.

You can find them on AliExpress or Ebay - e.g. https://www.aliexpress.com/item/32827427938.html
Or here is the manufacturer product page http://www.instrance.com.cn/en/ProductView.asp?ID=63

I don't generally have a need to measure beyond 2MHz right now, or if I do I have some RF current probes.

[Martin72]

Oh, interesting....
Never saw it before, looks like a tek/hioki clone.
Noisefloor 1mVrms=10mArms, accuracy 3%.
Hm-hm...Interesting.

I would not be surprised if the most expensive parts of the whole thing was the nice plastic case and the custom mechanical components.

If Micsig could pull out the technical design and real good building quality at such a low price, these "alternatives" are much more overpriced:


Rigol RP1002C for 1886€

Testec TT-CC990 for 1178€

R&S RT-ZC02 for 898€

Siglent CP4070A for 842€

[Hydron]

Huh, looks like Pintech is also doing Tek/Hikoi style probes too now (as well as some of the lower bandwidth ones similar to the links above):
http://en.pintech.com.cn/bls_html/urrentprobeblsarticlelist/bls_article_list12.html

I wonder how closely the construction matches the Tek ones - they business end of those hasn't really changed since the 60s!

Note that there is also Pintek as well in the same market space (albeit without the tek/hikoi type offerings) - I'm not sure who copies who (or if it goes both ways), but the names are bad enough.

[tautech]

Pintech is China company and Pintek is Taiwan.
AFAIK Pintek is the older company and first made the likes of DP-25 differential probes after which they were copied by Pintech.

Pintek's current probe offerings:
http://www.pintek.com.tw/product_classify/landersound-tail/index.php?Product_Site_Classify_SN=33672&PHPSESSID=5ubfkn4vbbie2hnjkpk2r07am6&Company_SN=6002

[Martin72]

I wonder how closely the construction matches the Tek ones - they business end of those hasn't really changed since the 60s!

There was no need to change anything, the concept was brilliant until nowadays.
And what the clones concerns - Looking at ebay, many parts from the tek probes are offered from china.
I think, they´ve examined it, now they don´t need them anymore and selling them...

[Weston]

Oh, interesting....
Never saw it before, looks like a tek/hioki clone.
Noisefloor 1mVrms=10mArms, accuracy 3%.
Hm-hm...Interesting.

I would not be surprised if the most expensive parts of the whole thing was the nice plastic case and the custom mechanical components.

If Micsig could pull out the technical design and real good building quality at such a low price, these "alternatives" are much more overpriced:


Rigol RP1002C for 1886€

Testec TT-CC990 for 1178€

R&S RT-ZC02 for 898€

Siglent CP4070A for 842€

Aside from the high bandwidth probes similar to the tek models, which are a hybrid current transformer and hall effect sensor, those alternatives are indeed even more overpriced. Its the same technology used in cheap PCB mount current sensors, a TMR/hall effect sensor and some commodity opamps.

I know because I have designed the same thing, except using a higher bandwith AMR sensor. Development is ongoing, but I am going to be launching it as a crowd funded project in the next few months https://www.flickr.com/photos/63341195@N08/albums/72157715180470002 

Test equipment has a huge markup compared to other products, their profit margins must be very large.

[JonM]

Trying to justify one of these for myself so trying to understand.  A few questions:
1.  Wouldn't you need to look at a much higher scope frequency to see any ringing?
2.  On a typical solar inverter or SMPS would there typically be any place that large a probe would fit that would be worth while to see ringing?

That specifically was a dig at the CP-65 and clones of it.. yeah.. it rings at that low of a frequency x_x

I'd point you to watch this guy's review of it.. and yeah he kinda looks like he came from metallica lol

The Kiss Analog guy compared the Micsig to a Fluke 80i-110s which appears to be identical to my HP 1146A current probe (delivered in an Agilent box in late 2000). Presumably neither Fluke nor HP made that probe.

I just got an email from Suse with the tracking number for my CP2100B so I will remove the battery from the 1146A and store it out of the way...

[maginnovision]

Well mine is supposed to be delivered today from Dave and as luck would have it I'm not home. Let's hope nobody decides to take it. Hasn't happened before but always a first time.

[Kean]

Mine has gone walkabout thanks to Australia Post.  It is still somewhere in Sydney, so hopefully it will arrive tomorrow.

[maginnovision]

Wow, that's pretty bad it makes it to my house in Ca, USA before you.

[Kean]

Wow, that's pretty bad it makes it to my house in Ca, USA before you.

Especially as shipping USA to AU is really slow right now, and I can't even get stuff delivered at all from some European countries, at least without paying a small fortune.

Postal service vs DHL Express
40km vs 12,000km
AUD $8 vs $30
6? days vs 5? days

And just for fun, tracking info currently shows it in a non-existent Sydney suburb "BROOKVALEOREST".  The suburbs of Brookvale and Frenches Forest are actually further away from me than Dave's lab.

[maginnovision]

Here in the US I get that kind of service from FedEx. All my packages go the wrong way a couple days before starting the right way and then they don't attempt delivery for a couple days.

Rise time good at 125.8ns and delay at 136ns at 10A, and 116ns at 100A using the same current. Looks pretty good.

[Kean]

Well it turns out the tracking info was bogus.  I got home from a full day client meeting to find it on my bench.  My wife had gone for a walk and collected it from the post office.  I'll take it into the office tomorrow, but not sure when I will have a chance to test it out.

[Elasia]

Mine is still in sydney... it left and came back a half hour later lol

good thing its just a spare and dont need it

[Cubdriver]

Mine's apparently made it through Customs, and will allegedly arrive on Thursday the 3rd.

-Pat

[JonM]

Mine was supposed to arrive on Thursday the 3rd but it arrived today, Tuesday the 1st.

I only did a quick test but it was nice to get power from the scope's USB port. I was reminded of old Tek and/or LeCroy scopes that had multi-pin LEMO connectors to power active probes.

Dave still has 10 CP2100B s left, get one before they are gone!

[EEVblog]

Well it turns out the tracking info was bogus.  I got home from a full day client meeting to find it on my bench.  My wife had gone for a walk and collected it from the post office.  I'll take it into the office tomorrow, but not sure when I will have a chance to test it out.

Tracking in the last month since the whole Victorian thing has been completely screwed up for some reason.
Many people saying the tracking just says "Picked up" and then nothing, and then suddenly it just turns up (two weeks later for Victorians).

[Cubdriver]

Mine showed up early, too - got it today.  I'm impressed - less than a week from Australia to CT.  Haven't gotten to play with it yet, but should soon.  Looks like a nice piece of kit.   

-Pat

[Elasia]

Well it turns out the tracking info was bogus.  I got home from a full day client meeting to find it on my bench.  My wife had gone for a walk and collected it from the post office.  I'll take it into the office tomorrow, but not sure when I will have a chance to test it out.

Tracking in the last month since the whole Victorian thing has been completely screwed up for some reason.
Many people saying the tracking just says "Picked up" and then nothing, and then suddenly it just turns up (two weeks later for Victorians).

Same crap here in the states but that has only been the last month or two from trump taking a wreaking ball to the postal service.  DHL goes through the post for the last mile in my area and it just got to them.  Maybe have it in a week if i am lucky.. cant even go pick it up as its in a pallet bundle at the local distribution plant and they arent allowed to pull from it.

When are you going to put down that fixed dumpster scale and uploaded this probes review?   

[Elasia]

Just got mine in, thanks Dave!

Interesting nugget... I have serial number 31000-1166 from Dave and is dated 8/17/20 with the 2 MHz label, and my other one here is 31000-1161 dated 7/22/20 and is labeled 2.5 MHz

So looks like they cut over just after 1160s, i'll have to set something up to compare them sometime

[Martin72]

Well....2Mhz or 2.5, I don´t care about - It´s way beyond my needs anyway...
But I´l habe a look on the serial number of my new arrived one in early august.
It´s on the work for testing it with "real" currents, so I can tell it later.

[EEVblog]

Just got mine in, thanks Dave!
Interesting nugget... I have serial number 31000-1166 from Dave and is dated 8/17/20 with the 2 MHz label, and my other one here is 31000-1161 dated 7/22/20 and is labeled 2.5 MHz
So looks like they cut over just after 1160s, i'll have to set something up to compare them sometime

I'd be interested to see a teardown difference in the 800kHz model.

[Kean]

Just got mine in, thanks Dave!

Interesting nugget... I have serial number 31000-1166 from Dave and is dated 8/17/20 with the 2 MHz label, and my other one here is 31000-1161 dated 7/22/20 and is labeled 2.5 MHz

So looks like they cut over just after 1160s, i'll have to set something up to compare them sometime

Mine has a serial number of 31000-1523 and is labelled as 2MHz.  Dated same as yours 2020-08-17.

[EEVblog]

Just got mine in, thanks Dave!

Interesting nugget... I have serial number 31000-1166 from Dave and is dated 8/17/20 with the 2 MHz label, and my other one here is 31000-1161 dated 7/22/20 and is labeled 2.5 MHz

So looks like they cut over just after 1160s, i'll have to set something up to compare them sometime

Mine has a serial number of 31000-1523 and is labelled as 2MHz.  Dated same as yours 2020-08-17.

All my units are 2MHz.
They might have re-labled old stock units. I don't believe there is any electrical change, they just decided to be more conversative with the spec based on production testing.

[Martin72]

My 2.5 Mhz version got the S/N 31000-1044 and is dated from 29.05.2020

[voltlog]

I recently got the CP2100A and I did a review & teardown on my yt channel I will link the video below the text. I also published some images from the teardown here so if you are interested in taking a closer look to identify any differences between the A and B variant, these should help. From what I could tell the markings on the sensor is 8877 which is the same as what you guys have on the 2MHz B variant, right? BTW if you are looking to get the CP2100A 800KHz there is a discount code mentioned on my video, you could use that to get a better deal.

[Algasman]

After following the discussions and trying to decide if I should go with the A or B version, I decided for the economic more bang for the buck A-Version.
Last week I got it delivered so I wanted to check the performance myself. The results are almost too good to be true, so I would like to know if you agree with my test setup.

SDG1032X as source, feeding a BNC-connector through 5 loops on the current probe clamp into 3x150 Ohms. SDS1204X-E Channel 1 Voltage of 50 Ohm load resistor, 10x Probe, Channel 4 CP2100A 2x (because of the 5 turn coil)

During measurement, I maintained 2,50V RMS over the load resistor, and measured the current as RMS (nominal 50mA)

This picture shows the voltage and current @800kHz, the nominal bandwidth of the CP2100A.

To me this looks much better than the specs, is my setup suitable for bandwidth measurement?

[Algasman]

No complaints so far ...
Looks like I got an A-Version with almost B-Specs. I’d say my unit has a bandwidth > 2MHz.
Maybe the binning Elasia suggested in an earlier post, isn’t so unlikely.
Would be nice to see a similar measurement with a real B Probe or other A versions.
Suggestions for a better test setup are also welcome.
Here are my measurements and an updated graph:

[bicycleguy]

I have a B model to compare.  Did you re-adjust the SDG output at each level.  I noticed the voltage across the resistor drops a little with frequency.

[Elasia]

I'd still put my money on that they would bin them

Solid design.. some flux in the components so just mass produce in one step with common components for cheap then tune after -> then a grading bin and done

[EEVblog]

After following the discussions and trying to decide if I should go with the A or B version, I decided for the economic more bang for the buck A-Version.
Last week I got it delivered so I wanted to check the performance myself. The results are almost too good to be true, so I would like to know if you agree with my test setup.
(Attachment Link)
SDG1032X as source, feeding a BNC-connector through 5 loops on the current probe clamp into 3x150 Ohms. SDS1204X-E Channel 1 Voltage of 50 Ohm load resistor, 10x Probe, Channel 4 CP2100A 2x (because of the 5 turn coil)
(Attachment Link)
During measurement, I maintained 2,50V RMS over the load resistor, and measured the current as RMS (nominal 50mA)
(Attachment Link)
This picture shows the voltage and current @800kHz, the nominal bandwidth of the CP2100A.
(Attachment Link)
To me this looks much better than the specs, is my setup suitable for bandwidth measurement?

The bandwidth of the A model is 2.3MHz? 

[Algasman]

I have a B model to compare.  Did you re-adjust the SDG output at each level.  I noticed the voltage across the resistor drops a little with frequency.

Yes
During measurement, I maintained 2,50V RMS over the load resistor, and measured the current as RMS (nominal 50mA)
I measured the voltage at the resistor with channel 1 of the scope and adjusted the output voltage of the signal generator accordingly. Constant voltage on the load resistor leads to a constant current through the loop (“RMS constant” since we're using AC)
The signal generator does not see a pure resistive load, there is also the inductance of the five turn coil. The dent around 4MHz could be some resonance effect.

[bicycleguy]

Here's a B
It doesn't look a whole lot better.

Code: [Select]

HZ,current(RMS)ma
          1 turn,    5 turns
50000,50,50
100000,48.6,48.7
200000,47.6
300000,48.1
400000,49.1
500000,49.6
600000,49.8
700000,48.8
800000,48.7,51.5
900000,48
1000000,47,50.2
1300000,44,52.2
2000000,37.7,42.6
2300000,35.6,40.9
2500000,34.6,40
3000000,33,38.2
3500000,31.9,37.0
4000000,33,38.4
4500000,31.2,38.4
5000000,23.5,31.7
6000000,10.7,13.1

Perhaps you can plot it with yours to compare.  I only used a single pass through probe.  Have redone some with 5 turns and it looks better.  Don't understand why it would matter as I rebased 50ma @ 50kHz,

[Martin72]

I´ve used the bodeplot function of my scope:

https://www.eevblog.com/forum/testgear/micsig-current-probe-cp2100b-tests-and-comparing/msg3072460/#msg3072460

(B-Model)

[Algasman]

Here's a B
It doesn't look a whole lot better.
# removed data #
Perhaps you can plot it with yours to compare.  I only used a single pass through probe.

Here’s the tough comparison:

The same shape and even the dent at around 4 MHz, only slightly better in the 100 to 600kHz range.

[Martin72]

And now, what are the conclusions ?

Please show your test setup, especially which resistor you´ve used for.

[bicycleguy]

Redid some data with 5 turns. See edit above.  Maybe should toss the 1 turn for consistency.  Edit maybe shouldn't compare spec to 5 tun.

[Hydron]

When I've done this kind of test I've used a 50R terminator on the scope input as both a well-matched load and the I-to-V conversion for the reference channel - basically have the co-ax from the sig-gen split into 2 wires at the half-way point (BNC to banana adapters are probably good enough here for <3MHz, I use a shielded box for higher frequencies), clamp onto the non-ground wire, then terminate into 50R on the scope. This gives 1V/A or 0.1V/A on the probe and 50V/A as the reference.

[Algasman]

After following the discussions and trying to decide if I should go with the A or B version, I decided for the economic more bang for the buck A-Version.
Last week I got it delivered so I wanted to check the performance myself. The results are almost too good to be true, so I would like to know if you agree with my test setup.
(Attachment Link)
SDG1032X as source, feeding a BNC-connector through 5 loops on the current probe clamp into 3x150 Ohms. SDS1204X-E Channel 1 Voltage of 50 Ohm load resistor, 10x Probe, Channel 4 CP2100A 2x (because of the 5 turn coil)
(Attachment Link)
During measurement, I maintained 2,50V RMS over the load resistor, and measured the current as RMS (nominal 50mA)
(Attachment Link)
This picture shows the voltage and current @800kHz, the nominal bandwidth of the CP2100A.
(Attachment Link)
To me this looks much better than the specs, is my setup suitable for bandwidth measurement?

The bandwidth of the A model is 2.3MHz? 

Yes, I was skeptical too, that’s why I put it up to discussion on your excellent forum!
The similar data from bicycleguys B-type probe pretty much confirms my claim and also Elasias binning theory.
Would be nice to see other A-type measurements (and also B ones)

[bicycleguy]

Algasman
I'm not sure that multiple turns thru the clamp are within the spec.  Sure it makes it work better as I show here:

Redid some data with 5 turns. See edit above.  Maybe should toss the 1 turn for consistency.

But how many turns? Where would you stop.  I now think the 5 turn should be dropped and if you re-did with just 1 time thru the clamp your results would match the spec.

[Martin72]

Would be nice to see other A-type measurements (and also B ones)

I´v turned a wire 10 times through the coil, for load I´ve used the integrated 50ohm input and then start bode plot.
Result, see link above.

[Noy]

Currently i have a CC-65 (working ok but its more a toy, but it has 10mA resolution...)
Normaly Im measuring in the below 5/3 A range.. So the micsig with 50mA resolution is a bit less attractiv but 800kHz (maybe more ;-) ) would be nice for switching regulator stuff these days (CP2100B would be nice but to expensive for the "sometimes" use case... ) and i can use multiple turns to get a higher resolution...

I found CP2100A for 140€ inkl. Shipping in Ali Express to Germany. Good offer or are these things fake / doesnt meet binning specs?
Should i order better from Batronix?

[Martin72]

Hi,

Please give a link to this offer(I´ve searching on Ali for it, best price was 233€..).
I guess, taxes will be added to the price so I would buy it from Batronix - No stress in case of warranty or money back guarantee...

working ok but its more a toy, but it has 10mA resolution...

Could you please show a pic with this resolution (10mA/Div.) ?

[Algasman]

Algasman
I'm not sure that multiple turns thru the clamp are within the spec.  Sure it makes it work better as I show here:

Redid some data with 5 turns. See edit above.  Maybe should toss the 1 turn for consistency.

But how many turns? Where would you stop.  I now think the 5 turn should be dropped and if you re-did with just 1 time thru the clamp your results would match the spec.

Using multiple turns is a common way to increase the probes sensitivity.
In my example the five turns increase the sensitivity by a factor of five so the signal to noise ratio is five times better than with just one turn.

But as usual, there is no free lunch.

Whereas the sensitivity increases linear with every turn, the insertion impedance increases by the square!
So five turns give you 25 times the impedance, 10 turns 100 times the insertion impedance.
It is like a transformer.

[Noy]

€ 131,71  18%OFF | BNC Port Strom Sonde Breite Verwenden Clamp 10A 100A Oszilloskop Zubehör USB Powered DC Testing Universal Mini Elektrische Meter
https://a.aliexpress.com/_mryzsHn


CC-65 Manual:
http://www.hantek.com/m/en/productdetail_77.html

[Martin72]

First thought, much too cheap to be true..

[Noy]

So asked the Ali sellers (found 2 with below 140€) some questions and it looks like "better don't touch!"
1. Thing the devices are without official case.
2. I asked them if these parts are genuine and no production "garbage".  If they met the official specification...

Both seller replied in a "talk around the corner" style :-D Don't know the exact english synonym for this speaking style..

The first replied nothing uptil now, only that it is without the case.
The second one replied "I can confirm the item will be the same as you can see on ads".

So both didn't say anything about genuine or specification... Maybe they didn't know... Or they knew and will not reply in an useable way (because they knew... ;-))

But without case / maybe without calibration sheet the devices are likely "production garbage / fake ones"...

I will order from Batronix i think. 5% off is possible if you ask for it....

[2N3055]

So asked the Ali sellers (found 2 with below 140€) some questions and it looks like "better don't touch!"
1. Thing the devices are without official case.
2. I asked them if these parts are genuine and no production "garbage".  If they met the official specification...

Both seller replied in a "talk around the corner" style :-D Don't know the exact english synonym for this speaking style..

The first replied nothing uptil now, only that it is without the case.
The second one replied "I can confirm the item will be the same as you can see on ads".

So both didn't say anything about genuine or specification... Maybe they didn't know... Or they knew and will not reply in an useable way (because they knew... ;-))

But without case / maybe without calibration sheet the devices are likely "production garbage / fake ones"...

I will order from Batronix i think. 5% off is possible if you ask for it....

Good decision...

[Algasman]

So asked the Ali sellers (found 2 with below 140€) some questions and it looks like "better don't touch!"
1. Thing the devices are without official case.
2. I asked them if these parts are genuine and no production "garbage".  If they met the official specification...

Both seller replied in a "talk around the corner" style :-D Don't know the exact english synonym for this speaking style..

The first replied nothing uptil now, only that it is without the case.
The second one replied "I can confirm the item will be the same as you can see on ads".

So both didn't say anything about genuine or specification... Maybe they didn't know... Or they knew and will not reply in an useable way (because they knew... ;-))

But without case / maybe without calibration sheet the devices are likely "production garbage / fake ones"...

I will order from Batronix i think. 5% off is possible if you ask for it....

I got mine from Batronix but without the 5% you get for some other equipment. But they ship very fast.

[Algasman]

As for my load, I did the following measurements using a LCR Meter @ 100kHz.

As a Resistor 50.12 Ohms, Theta 1.9 degrees

The series inductance 2,58uH with the clamp attached (5 turn coil with core)

and the series inductance 0.99uH without the clamp (5 turn air coil)
Regarding bicyleguys question

But how many turns? Where would you stop.

It depends on the device under test, putting the clamp around a conductor influences the DUT more or less. It’s the transformer rules you have to take into account. One can do as many turns needed as to get a good S/N ratio as long as the influence to the DUT is acceptable.

Pretty much as if a shunt resistor is inserted to use the voltage drop to measure the current. This burden voltage also influences the DUT. The reason why Dave designed the uCurrent Gold to keep this influence as small as possible.

[bicycleguy]

...
Regarding bicyleguys question

But how many turns? Where would you stop.

It depends on the device under test, putting the clamp around a conductor influences the DUT more or less. It’s the transformer rules you have to take into account. One can do as many turns needed as to get a good S/N ratio as long as the influence to the DUT is acceptable.

Pretty much as if a shunt resistor is inserted to use the voltage drop to measure the current. This burden voltage also influences the DUT. The reason why Dave designed the uCurrent Gold to keep this influence as small as possible.

What I was getting at is this thread is about comparing the performance of various probes against each other, including A vs  B Micsigs.  It doesn't make any sense to compare A with 5 turns vs B with 0.  Seems that the best is to compare no turns on every probe.

[Weston]

The official manual for the CP2100 does not give any noise values. Has anyone measured values for the peak to peak and RMS noise values for the probe?

[Algasman]

What I was getting at is this thread is about comparing the performance of various probes against each other, including A vs  B Micsigs.  It doesn't make any sense to compare A with 5 turns vs B with 0.  Seems that the best is to compare no turns on every probe.

Right, comparison makes only sense if the conditions are equal. That’s what we did.

It is perfectly fine to use only one turn (just the wire) if you have a decent signal. A signal generator producing a current of only 50 mA RMS on a probe in the 10 Amps range did not give me a good enough S/N.

That’s why I multiplied the input signal buy using turns and adjusting the input signal to read the 2.5 volts RMS at the load resistor, compensating for the insertion impedance.

[Algasman]

The official manual for the CP2100 does not give any noise values. Has anyone measured values for the peak to peak and RMS noise values for the probe?

I finally had the chance to measure noise (empty clamp).
With almost 5mA RMS of noise, measuring a 50mA RMS Signal (as in my test case) with just one turn is more guessing than measuring.

[Martin72]

I´ve used the averaging function of my scope in that range (or below, 20mA/div), then it works pretty well.
Still my probe is at work and at last, I´ll do some real measurements next week, working on a power inverter.
Last friday done a quick test, using a fluke87V and an bnc adaptor - Under 10A it got a remarkable accuracy in comparison to a ZES LMG670 poweranalyzer.
Will check this further, posting the results here.
Although I´m very confident with it, this one still makes me curious:

https://de.aliexpress.com/item/32827427938.html

Good, it will cost nearly double but still miles away from the stuff of hioki and it´s "brands"....

[Algasman]

I´ve used the averaging function of my scope in that range (or below, 20mA/div), then it works pretty well.
Still my probe is at work and at last, I´ll do some real measurements next week, working on a power inverter.
Last friday done a quick test, using a fluke87V and an bnc adaptor - Under 10A it got a remarkable accuracy in comparison to a ZES LMG670 poweranalyzer.
Will check this further, posting the results here.
Although I´m very confident with it, this one still makes me curious:

https://de.aliexpress.com/item/32827427938.html

Good, it will cost nearly double but still miles away from the stuff of hioki and it´s "brands"....

Looks nice, but if the stated sensitivity is true, then you get only 20mV at full scale with ~1mV RMS noise on top. I hope that’s not true.


But anyway, the CP2100A is good value vor money.
What makes me curious is that this that this probe and all the fancy ones have a degaussing function whereas our Micsig and the other economy probes have not.
If it is so important to get rid of the residual magnetization shouldn’t the economy probes also be degaussed from time to time.
If yes, how?

[Martin72]

Hi,

What makes me curious is that this that this probe and all the fancy ones have a degaussing function whereas our Micsig and the other economy probes have not.

I think it´s because of the (DC- current)measuring method, the ICP and also Tek/Hioki got the degaussing function on board.
The current compensating method "eliminates" the magnetic field caused by the current flow by using a compansation winding on the core, so they can also use these windings to demagnetize the coil.

If it is so important to get rid of the residual magnetization shouldn’t the economy probes also be degaussed from time to time.
If yes, how?

See the uni-t ut210e clampmeter thread, there are several possibilities described or look for a watch-demagnetizer in ebay or amazon ( should also work).

This is an still open question in this thread I try to answer it in the next days, by testing the micsig with maximum dc current, if the core gets magnetized after this, you´ll get a "huge" offset until it will be demagnetized.

[Algasman]

See the uni-t ut210e clampmeter thread, there are several possibilities described or look for a watch-demagnetizer in ebay or amazon ( should also work).

There are some treads regarding ut210e. You mean the tread with the solder gun?

I have a long forgotten pre millennium audio head demagnetizer. Would that work as well?

[Martin72]

Hi,

Have a look on this :

https://www.eevblog.com/forum/testgear/a-look-at-the-uni-t-ut210e/msg3120776/#msg3120776

And the following posts after.

[Martin72]

Hi,

At last I could doing the test on "real current" at work today...

I´ve measured several AC and DC currents on a power inverter (dc to ac).

Will put the values in a table, post them later in the weekend.

Values are compared to the ones of a ZES LMG670 high precision power analyzer at the same time.
Values of the micsig are read out via bnc-adaptor to a calibrated fluke 89 multimeter with mV range.

Nice:

Pressing the zero button will bring the output level nearly to zero ( some µV reading from the fluke).

Interesting:

Range is given by a maximum of 70Arms and 100A dc - When exceeding this, a sound and blink alert appears.
Starting at appx 71Arms..good - But when measuring DC, alert will appear not over 100Adc, it appears at appx 82Adc.

The good news:

I´ll let a current of appx 80Adc flowing through the clamp for say 5 minutes - After that, the offset of the clamp was only 260µV and could be bring back to zero again with no problems.

Martin

[Martin72]

Will put the values in a table, post them later in the weekend.

And here they are, "real" current measures...
As already written, I´ve used a ZES LMG670 Poweranalyzer for comparing and a Fluke 89IV for readout the micsig probe.
Don´t wonder about the random-like values, it´s a "living" test enviroment and I must get what I could get at the moment, so there´s is no 1,2,3,4 A possible - Real life work.

So we´ve done bandwith-measures, we´ve done rising time measures via the deskew fixture and finally "real" current measures instead of turning some wires through the clamp.
So my final verdict is already known.

Best from what you can get for the money - "More" will cost much more in this case, because in my opinion, only the hioki things will "beat" the micsig clearly and in every aspect.
So don´t waste your money for clamps which couldn´t do it better, but cost much more (see links in the very first post).
Personally, I need a clamp which can measure milli-amps to several amps and so I´ll still looking for an tekprobe with amplifier or giving the china-clone a try.
Until that, I could live easily with this gem here.

Noise in the mA range is no problem when you use the averaging function of your scope and normally, the micsig would already fits for everything I do.
But sometimes I´ll need a smaller clamphead.
Nevertheless, best bang for money, best bang under 1000bucks or more, depending on new or used probes.
That´s it.

Martin

[Martin72]

Looks nice, but if the stated sensitivity is true, then you get only 20mV at full scale with ~1mV RMS noise on top. I hope that’s not true.

It´s not true...

On their homepage, there are more detailed specs for it avaible.

On this, they claimed a conversation ratio of 100mV/A, with max 1mA noise....Not bad...

http://www.instrance.com.cn/En/ProductView.asp?ID=63

[EEVblog]

Micsig just said half of my new stock is 2MHz, and half is 2.5MHz. So pot luck 
They must have made the change/improvement half way through manufacturing my batch.
So I'm guessing all new units manufactured from now on will be 2.5MHz

[jragee]

Could this be the difference?

[Noy]

Yes same thing i spotted. And its something in the signalpath.. So its possible. Maybe  its same resistance like the one beside?
Didn't opend it up yet so not a safe guess..

[RobbiTobi]

Hi folks,

I would like to share some comments on the MicSig CP2100A&B current probes compared and discussed here.

First of all the CP2100A probe is a real bargain and good quality probe - I agree completely.
You all talk mainly about the bandwidth and FRF of the probes which are very similar for both (CP2100A&B) going up to approx. 3.5MHz.
That´s ok, but I am missing the focus on one important parameter of the probes here.
Just have a look at the phase-shift of these probes - this is more important than the max. bandwidth, i.m.h.o.
For what purpose you are using the current probe mainly? Probably, power/motor/switching testing applications.
So, measuring currents with a phase error of more than 10° will become critical for reliable power measurement and signal analysis.
In few words, these probes are only good for up to ~300kHz respectively - which is anyway quite impressive!
We have seen that both models (A&B) show a phase shift of 45° @ ~800kHz - upps, interesting due to the fact that the model A is marked 800kHz bandwidth.
My probe (A model) has a rise-time of about 100ns --> theoretical bandwidth of ~3.5MHz, however with phase-shift of ~5° @ 200kHz.

My personal assumption is that MicSig started this product by designing the A model first with "realistic specs".
And for marketing/sales reasons with the help of binning on cascaded filters "created" an "upgrade" for making money, but not really useful as the phase error is completely "out of order" above 800kHz.
Concluding, i.m.h.o the B model is not worth its money - just stay on the A model.

Cheers!

P.S.:
By the way, I suppose you all have checked the UT210E modifications made by Joe Smith years ago - great job Joe!
However, by changing few resistors only you can achieve a low-cost probe with a bandwidth of ~20kHz@2A and ~100kHz@20A - impressive current probe for some basic tasks!
Find a simple testing comparison with the CP2100A attached.

[Algasman]

I think the probe and it’s electronics introduce a more or less fixed delay which can be compensated by most digital oscilloscopes. If this delay is compensated to nearly zero, so is your phase shift at a given frequency. I compensated mine measuring the current and voltage of an ohmic resistor by aligning the two ac traces using the scopes delay function.
Give it a try!

[Algasman]

One the voltage and current traces are properly aligned you can use the oscilloscopes math function to calculate power or energy

[RobbiTobi]

You have to distinguish two facts:
1. the current probe has a physical signal delay, which is a constant delay as specified in the specs (here <150ns)
2. the phase-shift or phase-error is a function of frequency due to the signal processing chain (filters and more...)

You can compensate the constant signal delay i.e. by the CHskew setting of your scope - this is correct.
However, the phase-shift you can hardly compensate - only in the case you work with simple CW signals like a pure sinusoid.
As soon as you are dealing with complex signals like i.e. a square-wave you get a signal composed of harmonically related sinusoids with different frequencies (see Fourier series).
Your measured signal of the probe will get shifted and distorted due to the phase-shift error vs. frequency.
In that case you hardly can compensate the phase-shift of each sinusoid component and your procedure as described will not work anymore.

[Noy]

You are right if you want to use it for power measurments. But even then you don't know is the Phase shift from your load or current clamp..
But if you use the clamp to verify current curves for example Motor/power supply switching current through inductor you don't have to care about Phase shift inside the clamp...

Would be interesting if Martins New Toy (other thread) has a phase shift / correction..

[Algasman]

I tried to measure delay over frequency - unfortunately with the following restrictions/constraints:

Sinusodial Current of only 140mA Peak-Peak measured in 10A Range of current probe, therefore very noisy.
Proper measurement should be done with 1 to 5 Ampere signals, I don’t have a source for that.
Signals are 32x averaged
50 Ohm load resistor
Phase & Delay measurement with oscilloscope with high standard deviation on low frequencies due to noise.
Temperature also seems to have an effect on delay

I’d say this kind of test setup is only suitable for frequencies > 100kHz
The almost constant delay from 300kHz - 2MHz is impressive (bang for the buck)
The test equipment is the same as in my other posts

[RobbiTobi]

Would be interesting to see how your probe works in reverse mode.
Just repeat your FRF and delay measurement with reverse current and see if the response is still the same... if the probe is well balanced.

[Algasman]

The signal was unbiased, so it should include both. I put my gear away, but if I give it another try, I could measure the rising and the falling delay.
The 10mA offset was an oscilloscope issue, both channels were AC coupled. The offset did not affect the measurement, I checked that.

[rhb]

You have to distinguish two facts:
1. the current probe has a physical signal delay, which is a constant delay as specified in the specs (here <150ns)
2. the phase-shift or phase-error is a function of frequency due to the signal processing chain (filters and more...)

You can compensate the constant signal delay i.e. by the CHskew setting of your scope - this is correct.
However, the phase-shift you can hardly compensate - only in the case you work with simple CW signals like a pure sinusoid.
As soon as you are dealing with complex signals like i.e. a square-wave you get a signal composed of harmonically related sinusoids with different frequencies (see Fourier series).
Your measured signal of the probe will get shifted and distorted due to the phase-shift error vs. frequency.
In that case you hardly can compensate the phase-shift of each sinusoid component and your procedure as described will not work anymore.

Once it has been digitized you can correct phase and amplitude errors with DSP to a high degree of accuracy.  This is essentially no different from calibrating an analog  SA/TG or  VNA.  For an SA/TG, you store a thru cal and apply that.  Then any difference is device error.  The cost is 2 FFTs and  a multiply.  Something an FPGA can do *very* fast at typical sweep lengths.  This yields sampling as the limiting variables, sample rate and # of bits.

Take a look at this:

https://www.eevblog.com/forum/testgear/a-high-performance-open-source-oscilloscope-development-log-future-ideas/msg3326904/#msg3326904

We've had hours of discussion about what can be done via DSP on an FPGA.  I have extensive seismic DSP experience.  There is very little cost to doing two FFTs per trace window and a multiply per frequency.  And once you've got a signal in both time and frequency you can do anything quite cheaply.

Ideally you would load FPGA images from flash memory which could be loaded to the fabric in any order and with any connections so that one can form arbitrary pipelines.  This allows writing highly specialized fabrics for triggers and other cool stuff.

Have Fun!
Reg

[Peter_O]

Just got a CP2100A. For my very basic purposes this 800kHz version is fine.



The last posts about phase shifts are many months old, but nevertheless:
Here's a quick bode plot of my CP2100A, showing the phase shift.


100kHz square wave, magnitude of 200ns rise time well within spec.
(F1 blue: average n=128)

 

A very basic test with a 60W light bulb:



DMM shows 255.6 mA
Micsig shows RMS 258.6 mA




And a shot of a PC power supply starting into standby with about 20A within the first half wave. Micsig in 100A mode.

[Curious]

Apologies, waking up an old post...

Can anybody help translate MicSig's specified Accuracy, identical language for CP2100A & B.  It's entitled "DC accuracy" but then uses "Apk" which I assume means "Amperes Peak", which wouldn't be DC.

DC accuracy (typical)     
3%±50mA (10A)                          {I'm guessing this line is DC, on 10A range, but no equivalent for 100A range}

4%±50mA(100A,500mA~40Apk)  {maybe AC accuracy if Amps peak is <40Amps, up to bandwidth limit  .8 or 2Mhz}

15%(100A,40Apk~100Apk)     {maybe AC accuracy if Amps peak is >40Amps, up to BW  .8 or 2Mhz.  saturation of steel core??  so reads lower than reality}