Micsig Current Probe CP2100A/B Tests and Comparing

[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?