New MicSig/EEVblog DP10007 HV Differential Probe

[nikifena]

I've got DP10013 but actually I prefer 10x/100x probe.

Just wondering about a simple hack with the input resistor dividers modifying the existing 50x/500x to 10x/100x diff probe.

[Hydron]

DP10013 input divider is 500:1, followed by a buffer, then a 1x/10x gain output amp (gain switching done with a relay in a pretty janky way that doesn't give the most confidence in a good CMRR match between ranges, as there is only one trimmer for both).

To increase the gain the input divider low-leg R and C would need changing. There will be side effects to doing this, not the least of which would be a proportional reduction in the common mode input range (needs to stay within the bounds of the input buffer, which is the limiting factor).

Screws are also under the bloody sticker, asshole move there 

[EEVblog]

Has anyone measured the CMRR of the DP10007?
I measured well outside the spec at 10MHz, really obvious when directly compared with the HVP70 which has identical specs. Can anyone else confirm?
Micsig are investigating.

[Hydron]

One of my DP10013s was well out of spec all the way from DC in one range (forget which but could check). Sent it in for an exchange.

Is yours out just at higher frequencies, or all the way from DC as well? I think I checked mine at DC by using a megger to apply ~500V of CM voltage (referenced to the BNC shield, plugged into a multimeter). Alternatively apply mains .
There is a single DC CMRR adjust pot and a trimmer cap for each divider leg in the DP10013 - if yours is OK at DC but not higher then it could be the latter being out.

Would certainly be interested in pics of the inside - wondering if it is different to the DP10013 or if they have just tweaked the divider/amplifier. Especially curious as to how they are doing the range switching (this is one of the weak points of the other one, and is how it was possible for one range to be out but the other OK). Would also be interested in a frequency response sweep.

Might be able to find my plots of DP10013 CMRR vs frequency if that helps.

[EEVblog]

Is yours out just at higher frequencies, or all the way from DC as well? I think I checked mine at DC by using a megger to apply ~500V of CM voltage (referenced to the BNC shield, plugged into a multimeter). Alternatively apply mains .

Wasn't able to test with the simple setup I used. Problem at 10MHz, so I just informed them and left it at that for now.

[mrprecision]

I have the DP10013 and also the DP10007 probe. I can do some measurements if someone want. Let's discuss what an how I should measure. So we can compare both probes.

[mrprecision]

I have tested my Micsig DP1007 probe. In the first test, I have shorten the inputs and looked for the noise (reason why I bought the Probe). Then I had a look with my scope in both settings. The 10:1 works fine, but hte 100:1 has an interference influence. It's from the inside of this device. My other probe Micsig DP10013 works in both settings fine with the same boundary conditions.



Has anybody the same problem?

[ExaLab]

Probably, the DP10007 uses a different HW approach regarding its internal power supplies (with respect te previous models).
In this new model, the positive supply (5Vdc) must be raised up to about 10Vdc and this additional step-up circuit could cause the interference you observe.

The different philosophy of the internal supply voltages would also seem confirmed by the higher power consumption declared by the manufacturer for this new version.

[beanflying]

Subbing in. I got a DP10013 a while ago and can run it up against Valhalla AC Calibrator (I have been meaning to for a while) over a range in the next few days. Also interested in the guts of the 10007 for a comparison.

[Kibabalu]

I have tested my Micsig DP1007 probe. In the first test, I have shorten the inputs and looked for the noise (reason why I bought the Probe). Then I had a look with my scope in both settings. The 10:1 works fine, but hte 100:1 has an interference influence. It's from the inside of this device. My other probe Micsig DP10013 works in both settings fine with the same boundary conditions.



Has anybody the same problem?

don't see this issue with my DP10007.

How do you supply your probe?

[beanflying]

Rule of adapters you will never have enough 

The 4mm posts on my Calibrator are to short to take the points on the multimeter type probe/jacks (suits most others I have with a quick check). I could have made a MF set but went with spade lugs instead for a variation in the box.

[mrprecision]

I have done some Measurements with the DP10013 and DP10007 for comparison:

• Channel 1: Generator
• Channel 2: DP10013
• Channel 2: DP10007

Frequency Response Divider x10 x50

Comment: Usefull up to 10MHz




Frequency Response Divider x100 x500

Comment: Usefull up to 10MHz




Noise Divider x10 x50 (Standard Deviation = RMS Noise)

Comment: 33mV (DP10013) vs 13mV (DP10007)




Noise Divider x100 x500 (Standard Deviation = RMS Noise)

Comment: 107mV (DP10013) vs 26mV (DP10007)




Common Mode Rejection  x10 x50




Common Mode Rejection  x100 x500




Step Response x10 x50




Step Response x100 x500

[BreakingOhmsLaw]

I have a DP10007 as well.

CMRR measured and (vs spec value) on 10x

50Hz   -70dB  (-80)
20kHz -55dB  (-60)
1MHz  -52dB (-50)
10MHz -33,2dB (-40)

No information how Micsig measures the CMRR though.
Can we agree on a common setup? Input leads twisted x-times, input signal etc.?

[mrprecision]

Here you can see the setup for my common mode measurement:





A question is how save is the device. What happen if the BNC connector is not grounded via the scope (as in the manual recommended). The impedance between the measuring cable and the BNC shield is not high enough to pass the electronic device test (devices of class II).

[mrprecision]

I did some further measurements regarding safety. For the measurement I followed up the IEC 61010-1 (Safety requirements for electrical equipment for measurement, control, and laboratory use).

In part 6.3 "limit values for accessible parts" "level in normal condition", there is a current level of 0.5mArms for measuring circuit of figure A2 (2k ohm load) for sinussoidal a.c. with frequencies up to 100Hz.

I put my maximum measuring voltage of arround 250Vrms @ 50Hz at the inputs. Then I measured the current flow from the BNC shield to one of the input pins. The measuring result was 0.143mArms. This value is lower than 0.5mArms and therefore not be hazardous for llife. So the probe should be save.

[EEVblog]

I have a DP10007 as well.

CMRR measured and (vs spec value) on 10x

50Hz   -70dB  (-80)
20kHz -55dB  (-60)
1MHz  -52dB (-50)
10MHz -33,2dB (-40)

No information how Micsig measures the CMRR though.
Can we agree on a common setup? Input leads twisted x-times, input signal etc.?

I'll shoot a video on this in a few day when I have time. MicSig are still looking into it.
My setup is a 50ohm terminator on the scope, 10MHz sine from the function gen as large as possible, measured and confirmed on one scope channel.
Leads of both inputs twisted reasonably tightly and both inputs shorted and connected across the 50 ohm load. Then using 20*Log (output p-p / Vgen p-p)
I use a HVP70 for comparison which is supposed to have indentical CMRR specs and the Micsig is way higher.
They say they are still working on it, but have not confirmed mt setup is correct or what setup they are using.

[BreakingOhmsLaw]

Okay, repeated the measurement with what I think Dave meant:


Some remarks:
 - Scope is set to 20MHz Bandwith limit
 - V/div fine adjustment used to maximize amplitude in order to optimize ADC quantization.
 - Lead of DP10007 twisted 8x.
 - Measurements below 1MHz are difficult because the common mode signal is swamped in the noise. I used persistence and color grading and estimated the amplitude of the "cloud". 
 - The BNC splitters will introduce an error, ignoring that for now.

            x10    x100    Spec
50  Hz      -70    -56     -80
20 kHz      -50    -54     -60
 1 MHz      -49.5  -37.6   -50
10 MHz      -32.2  -20     -40

A final note: My DP10007 has a slight positive DC offset. Does anyone else see this?

[mr.os]

I also made a measurement with my DP10007. I measured it with a HP 89410A and have so some graphs:

The green trace is the CMRR of the x10 range and the blue trace is the CMRR of the x100 range (the analyzer has done the math that the graphs are the direct CMRR). Some points (measured partially in another mode where I can't generate such a nice plot):

	x10	x100
50Hz	-82dB	-79dB
20kHz	-59dB	-57dB
100kHz	-56dB	-57dB
1MHz	-50dB	-42dB
10MHz	-37dB	-22dB

So at least the x10 spec are in my measurements not so far away from the manufacturers spec. My probe is also relative new, maybe they have changed something.
My measurement setup:


Also checkd for DC offset and with shorted inputs the x10 range has around 360µV and the x100 range around 280µV. So this is fine.

[mf_ibfeew]

>A final note: My DP10007 has a slight positive DC offset. Does anyone else see this?
I had a similar problem with my DP20003, more than 12V ofset (with the 200:1 range)
After complaint I got no new shiny probe, instead I got an email with the following instructions:
procedure for Micsig Auto-offset-calibration:
- connect probe to power (USB), switch on, short both input leads
- push down both range buttons simultaneous, after some time you will hear some relays clicking inside. The offset-error should be zero now
- switch off, switch on, test offset, be happy
- if my english is to bad: look at 
Maik

[mrprecision]

Could anyone review my noisemeasurement?

[BreakingOhmsLaw]

Could anyone review my noisemeasurement?

Here you go:

[SimpleOne]

Is anyone aware if any changes have been made to the DP10007 since the testing reported above?

I'm hunting around for some relatively low priced diff probes for 3Ph motor tests. I currently have one HVP70 from Dave's store when he had them in stock. Would people suggest hunting down additional sapphire probes, or are the DP10007's now a better alternative for the money?

[EEVblog]

Is anyone aware if any changes have been made to the DP10007 since the testing reported above?
I'm hunting around for some relatively low priced diff probes for 3Ph motor tests. I currently have one HVP70 from Dave's store when he had them in stock. Would people suggest hunting down additional sapphire probes, or are the DP10007's now a better alternative for the money?

They should be way better bang-per-buck. I have not heard back from Micsig, will need to give them a poke as I'm now a long time without either probe.
Sapphire increased their FOB prices by like 20% or something, so I dropped them. They are nice probes, but the price was already high enough, and the margins low. I made less on those probes than my meters at half the price.

[mrprecision]

For me the DP10007 HV Probe is ok after I got a replacement.

[ExaLab]

For me the DP10007 HV Probe is ok after I got a replacement.

What was the exact problem with your old probe for asking for a replacement?
Thanks a lot