Author Topic: Pearson current monitor model 1330 teardown (100kA)  (Read 572 times)

Offline Mads Barnkob

  • Administrator
  • Executive Board Member
  • *****
  • Posts: 2307
  • Karma: +73/-0
  • Denmark
    • View Profile
    • Kaizer Power Electronics
Pearson current monitor model 1330 teardown (100kA)
« on: June 01, 2024, 08:22:28 PM »
Repost: Was requested from a reader, as the large pictures are no longer available on the original 4hv thread.

January 2015.
So, there I was, happy about my latest purchase, a huge and extremely noise immune 100kA current monitor.



Testing it on a small cap bank did however reveal that something was wrong with it.



I tried to write Pearson tech support for help with the above image attached.
Quote
I have a second hand Pearson current monitor model 1330 that is very ill behaving compared to my model 101.

I made some different measurements with a little description on the bitmaps from my oscilloscope. The measured currents are around 12-16kA.

The 50 Ohm attenuator mentioned in the image is a 50 Ohm -10dB attenuator.

I also tried looping the coax cable through large ferrites for common mode noise suppression without any luck. Neither did it help with a 50 Ohm termination at the oscilloscope input.

I put the different measurements together in a imgur album.

The reply from Pearson
Quote
Thank you for the Imgur data. First off, I would not recommend using our current monitors with external terminations other than 50 Ω and 1 MΩ. Our current monitors have a 50 Ω output impedance and the sensitivity is designed to work into an oscilloscope at 1 MΩ input impedance. Using the 50 Ω setting on the oscilloscope with cut the sensitivity in half. Also, the 1330 has an internal series resistor to make the output impedance 50 Ω so putting different loads in parallel with the unit may not have the intended result.

What is the input setting on your oscilloscope? Are you using an external 50 Ω termination with the 50 Ω attenuator? From #1, at ~14 kA I would expect the 1330 channel to be ~10-20 V with a -10 dB attenuator, depending on termination. Since the sensitivity appears off it could be a damaged series resistor or termination resistance. From #2, it looks like the internal termination of the 1330 could have been damaged. Has this unit been used for measuring damped ringing waveforms in the past?

Have you measured the terminal resistance of just the 1330 with the DMM? The 1330 should measure ~46 Ω. If it is much higher this usually indicates a damaged series resistor which can affect the sensitivity when using a 50 Ω load.

I requested help on repairing the unit and all communication stopped after that.

As I had nothing to loose, except money already lost, I decided to take it apart to find a faulty component and maybe repair it on my own.

The green paint is thick, hard and sticks very good to the copper surface, it was a messy and long job just to remove enough of it to find out how it was assembled.




Prying the first copper shield off was a whole evening job. Notice that the two shields are not connected in the through-hole, there is only a tiny narrow slot for the magnetic field to enter the CT.




Carefully chipping the epoxy off was a job that took some evenings week upon week, it was over a long period.




After I had removed the inner copper shielding I lost all hope and interest when there was just another layer of epoxy and this time chipping it off was not an option, now there is components and a ?brittle? core involved. I left it on a shelf for a long time.

Last week I found a large pan on the scrap yard and thought, I will try to cook it and see what that does to the epoxy. Just add salt and pepper for a tasty transformer soup.




The last remaining copper part with connector in it came loose in first boiling run and a cable revealed where the series resistor was located. Carefully removing the softened epoxy, the series resistor came apart in tiny pieces and from the look of it, it was once warm, maybe too warm. This was however also the only visible damage I found.




Connector got out in the free




On the inside of the through-hole, which by the way was only accessible for electromagnetic waves through a thin 2-3 mm wide slot between the shieldings from each side of it, there was another weird coil of 5-6 hair thin wires, wave shaped, in parallel on a wide piece of tape, tapped for each 30mm with a gold wire into the distributed load resistors on the regular large coil. See schematic.




The thin wave-shaped wires should be visible from these two different angles



Schematic made from my best guess on how its connected, number of distributed load resistors it not accurate.




As you can see, I tried replacing the 39R series resistor, identified by the rings it left in the epoxy, and not with a great result, DC resistance is still far from specification.

Tearing it down, the money was not all a waste, but still a pretty expensive teardown :)

End of story, so far. February 2016.
https://kaizerpowerelectronics.dk - Tesla coils, high voltage, pulse power, audio and general electronics
https://www.youtube.com/KaizerPowerElectronicsDk60/join - Please consider supporting the forum, websites and youtube channel!

Offline klugesmith

  • High Voltage Senior
  • *****
  • Posts: 741
  • Karma: +22/-0
    • View Profile
Re: Pearson current monitor model 1330 teardown (100kA)
« Reply #1 on: June 05, 2024, 01:42:04 AM »
Glad to see the re-post, Mads.  Nice work.
Am reminded that I have a couple of Pearson high frequency CT's that turned up at flea market 10 or 15 years ago.
I had to walk 1 km to get $50 or $100 cash for the purchase.
So far untested, but they beckon me to retire from day job and clean up the home workshop.

As you requested, I will re-post my story and pictures from 4hv report (in about 2010) about rigid, reproducible Rogowski coils.
My calibration pulse generator, like yours, has RLC circuit with similar dynamics as pulser of interest (a can crusher).
With 1/100 of the voltage and current. 1/10000 of the energy.  Nice thing about ironless instrumentation is linearity over decades of signal strength.
 

High Voltage Forum

Re: Pearson current monitor model 1330 teardown (100kA)
« Reply #1 on: June 05, 2024, 01:42:04 AM »

 


* Recent Topics and Posts

post Re: Problem with SSTC
[Solid State Tesla Coils (SSTC)]
Nunu00
Today at 10:17:36 PM
post Making a HV prove
[Electronic Circuits]
Alberto
Today at 09:01:08 PM
post Re: Problem with SSTC
[Solid State Tesla Coils (SSTC)]
davekni
Today at 01:33:37 AM
post Re: Problem with SSTC
[Solid State Tesla Coils (SSTC)]
Nunu00
Today at 12:17:32 AM
post Re: Restoring a Rogowski coil calibrator
[Capacitor Banks]
davekni
July 11, 2024, 07:38:26 PM
post Re: Restoring a Rogowski coil calibrator
[Capacitor Banks]
klugesmith
July 11, 2024, 06:30:00 PM
post LOD No Double Resonant SSTC?
[Solid State Tesla Coils (SSTC)]
ColinHeath
July 11, 2024, 06:08:30 PM
post Re: FIRST DRSSTC SKM400GB128D OCD SETTING
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Admiral Aaron Ravensdale
July 11, 2024, 12:24:56 PM
post Re: Strange QCW Streamer Behavior
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
July 11, 2024, 06:42:23 AM
post Re: Syntherrupter Lightsaber Sender Programming
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Cameron Prince
July 11, 2024, 05:46:07 AM
post Syntherrupter Lightsaber Sender Programming
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Cameron Prince
July 11, 2024, 05:26:51 AM
post Re: Strange QCW Streamer Behavior
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ZakW
July 11, 2024, 02:50:54 AM
post Strange QCW Streamer Behavior
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Coupling
July 11, 2024, 12:59:55 AM
post Re: Help for people buying the "12-48 Volt 1800/2500 Watt ZVS induction Heater"
[Electronic Circuits]
petespaco
July 10, 2024, 07:10:34 PM
post Re: Understanding and tracking upper and lower poles of QCW DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
July 10, 2024, 06:52:42 PM
post Re: Understanding and tracking upper and lower poles of QCW DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Anders Mikkelsen
July 10, 2024, 06:28:19 PM
post Re: FIRST DRSSTC SKM400GB128D OCD SETTING
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Alex_1996
July 10, 2024, 01:34:09 PM
post Re: Silicon(e) plasma
[General Chat]
alan sailer
July 10, 2024, 12:09:06 AM
post Re: Problem with SSTC
[Solid State Tesla Coils (SSTC)]
Nunu00
July 09, 2024, 11:52:00 PM
post Understanding and tracking upper and lower poles of QCW DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Simranjit
July 09, 2024, 07:37:22 PM
post Re: Silicon(e) plasma
[General Chat]
MechatEng2023
July 09, 2024, 07:30:05 PM
post Re: UD2.7C outputs very odd single square wave pulses
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
July 09, 2024, 03:30:49 AM
post Re: UD2.7C outputs very odd single square wave pulses
[Dual Resonant Solid State Tesla coils (DRSSTC)]
verliebt_in_neukölln17
July 09, 2024, 12:51:02 AM
post Re: UD2.7C outputs very odd single square wave pulses
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
July 08, 2024, 11:30:44 PM
post Re: Why so cheap?
[General Chat]
alan sailer
July 08, 2024, 10:57:10 PM
post UD2.7C outputs very odd single square wave pulses
[Dual Resonant Solid State Tesla coils (DRSSTC)]
verliebt_in_neukölln17
July 08, 2024, 10:21:01 PM
post Why so cheap?
[General Chat]
MRMILSTAR
July 08, 2024, 09:55:24 PM
post Re: Syntherrupter - A Feature-rich, Polyphonic Interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Cameron Prince
July 08, 2024, 09:18:21 PM
post Re: Syntherrupter - A Feature-rich, Polyphonic Interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Max
July 08, 2024, 05:17:49 PM
post Re: Syntherrupter - A Feature-rich, Polyphonic Interrupter
[Computers, Microcontrollers, Programmable Logic, Interfaces and Displays]
Cameron Prince
July 08, 2024, 04:49:20 PM
post Re: Tesla coil in FEMM
[Beginners]
Simranjit
July 08, 2024, 04:28:43 AM
post Re: Tesla coil in FEMM
[Beginners]
davekni
July 08, 2024, 04:06:53 AM
post Tesla coil in FEMM
[Beginners]
Simranjit
July 08, 2024, 03:46:49 AM
post Re: Best core material for QCW Buck modulator ?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Simranjit
July 08, 2024, 02:42:00 AM
post Re: QCWDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ZakW
July 08, 2024, 01:37:55 AM
post Re: First DRSSTC Build- Issues with Fibernet project
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Sebigamer
July 08, 2024, 12:53:08 AM
post Re: QCWDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Anders Mikkelsen
July 08, 2024, 12:49:48 AM
post Re: Silicon(e) plasma
[General Chat]
alan sailer
July 07, 2024, 11:15:35 PM
post Silicon(e) plasma
[General Chat]
MechatEng2023
July 07, 2024, 11:04:43 PM
post Re: QCWDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ZakW
July 07, 2024, 09:39:07 PM
post Re: First DRSSTC Build- Issues with Fibernet project
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
July 07, 2024, 05:32:56 PM
post Re: QCWDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Anders Mikkelsen
July 07, 2024, 02:52:19 PM
post Re: No change in Phase Lead
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Anders Mikkelsen
July 07, 2024, 02:50:04 PM
post Re: Best core material for QCW Buck modulator ?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Anders Mikkelsen
July 07, 2024, 02:20:11 PM
post Teardown of a APC SmartUPS VT 40 kVA
[Electronic Circuits]
Mads Barnkob
July 07, 2024, 10:02:22 AM
post First DRSSTC Build- Issues with Fibernet project
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Sebigamer
July 07, 2024, 09:23:58 AM
post Re: QCWDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ZakW
July 07, 2024, 12:44:53 AM
post Re: FEMM tesla coil simulation
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Simranjit
July 07, 2024, 12:08:50 AM
post Re: FEMM tesla coil simulation
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
July 06, 2024, 10:35:49 PM
post FEMM tesla coil simulation
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Simranjit
July 06, 2024, 09:42:43 PM
post Re: No change in Phase Lead
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
July 06, 2024, 06:06:23 PM
post Re: No change in Phase Lead
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Admiral Aaron Ravensdale
July 06, 2024, 10:21:16 AM
post Re: No change in Phase Lead
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Admiral Aaron Ravensdale
July 06, 2024, 10:15:42 AM
post Re: QCWDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Simranjit
July 06, 2024, 04:53:56 AM
post Re: No change in Phase Lead
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
July 06, 2024, 04:42:16 AM
post Re: QCWDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
July 06, 2024, 04:09:50 AM
post Re: Best core material for QCW Buck modulator ?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
July 06, 2024, 03:07:11 AM
post Re: No change in Phase Lead
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
July 06, 2024, 03:05:18 AM
post Re: QCWDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ZakW
July 06, 2024, 02:37:16 AM
post Re: QCWDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Simranjit
July 06, 2024, 02:20:14 AM
post QCWDRSSTC - Project Build
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ZakW
July 06, 2024, 01:55:14 AM
post Re: No change in Phase Lead
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
July 05, 2024, 11:50:37 PM
post Best core material for QCW Buck modulator ?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Simranjit
July 05, 2024, 10:07:04 PM
post 230v Tesla coil and krypton gas
[Spark Gap Tesla Coils (SGTC)]
gravitysrainbow
July 05, 2024, 07:13:25 PM
post Re: No change in Phase Lead
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Admiral Aaron Ravensdale
July 05, 2024, 06:17:13 PM
post Re: Phase lead inductors
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
July 04, 2024, 11:40:45 PM
post Re: Sling Psychrometer
[Laboratories, Equipment and Tools]
Twospoons
July 04, 2024, 11:02:32 PM
post Phase lead inductors
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
July 04, 2024, 06:28:08 PM
post Re: Sling Psychrometer
[Laboratories, Equipment and Tools]
klugesmith
July 04, 2024, 12:31:40 AM
post Re: FIRST DRSSTC SKM400GB128D OCD SETTING
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Alex_1996
July 04, 2024, 12:07:21 AM
post Re: FIRST DRSSTC SKM400GB128D OCD SETTING
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Alex_1996
July 04, 2024, 12:06:17 AM
post Re: FIRST DRSSTC SKM400GB128D OCD SETTING
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Benjamin Lockhart
July 03, 2024, 10:51:23 PM
post Re: FIRST DRSSTC SKM400GB128D OCD SETTING
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Mads Barnkob
July 03, 2024, 09:44:14 PM
post Re: Coax cable for DRSSTC interrupter?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Admiral Aaron Ravensdale
July 03, 2024, 08:48:13 PM
post Re: Coax cable for DRSSTC interrupter?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Simranjit
July 03, 2024, 08:24:50 PM
post Re: FIRST DRSSTC SKM400GB128D OCD SETTING
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Alex_1996
July 03, 2024, 08:12:55 PM
post Re: Coax cable for DRSSTC interrupter?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Admiral Aaron Ravensdale
July 03, 2024, 07:29:53 PM
post Re: FIRST DRSSTC SKM400GB128D OCD SETTING
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Admiral Aaron Ravensdale
July 03, 2024, 07:21:38 PM
post Re: FIRST DRSSTC SKM400GB128D OCD SETTING
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
July 03, 2024, 05:05:39 PM
post Re: FIRST DRSSTC SKM400GB128D OCD SETTING
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Alex_1996
July 03, 2024, 04:29:53 PM
post Re: FIRST DRSSTC SKM400GB128D OCD SETTING
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
July 03, 2024, 04:09:11 PM
post FIRST DRSSTC SKM400GB128D OCD SETTING
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Alex_1996
July 03, 2024, 02:47:18 PM
post Re: Eliminating discharges from a SSTC
[Solid State Tesla Coils (SSTC)]
Alex_1996
July 03, 2024, 01:35:24 PM
post Re: Coax cable for DRSSTC interrupter?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
flyingperson23
July 03, 2024, 02:19:03 AM
post Re: Coax cable for DRSSTC interrupter?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
verliebt_in_neukölln17
July 03, 2024, 01:19:50 AM
post Coax cable for DRSSTC interrupter?
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Simranjit
July 02, 2024, 11:29:18 PM
post Re: Is this a good pulse experiment capacitor?
[Capacitor Banks]
Mads Barnkob
July 02, 2024, 09:59:07 PM
post Re: LabCoatz Staccato QCW No straight sparks
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ZakW
July 02, 2024, 09:55:53 PM
post Re: Capacitor wiring for single phase 240 to split phase (180 degree) 240v
[Capacitor Banks]
klugesmith
July 02, 2024, 09:44:55 PM
post Re: LabCoatz Staccato QCW No straight sparks
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Admiral Aaron Ravensdale
July 02, 2024, 07:51:37 PM
post Re: LabCoatz Staccato QCW No straight sparks
[Dual Resonant Solid State Tesla coils (DRSSTC)]
ZakW
July 02, 2024, 06:14:07 PM
post Is this a good pulse experiment capacitor?
[Capacitor Banks]
FPS
July 02, 2024, 06:02:38 PM
post Re: LabCoatz Staccato QCW No straight sparks
[Dual Resonant Solid State Tesla coils (DRSSTC)]
Admiral Aaron Ravensdale
July 02, 2024, 11:37:46 AM
post Re: Building my first DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
davekni
July 02, 2024, 05:22:10 AM
post Re: Coulometric hourmeters
[Laboratories, Equipment and Tools]
davekni
July 02, 2024, 05:16:30 AM
post Re: Building my first DRSSTC
[Dual Resonant Solid State Tesla coils (DRSSTC)]
drobotk
July 01, 2024, 11:50:12 PM
post Re: Restoring a Rogowski coil calibrator
[Capacitor Banks]
klugesmith
July 01, 2024, 08:48:53 PM
post Uses for Weston's Little Bee probe
[Laboratories, Equipment and Tools]
klugesmith
July 01, 2024, 08:40:59 AM
post Re: Coulometric hourmeters
[Laboratories, Equipment and Tools]
klugesmith
July 01, 2024, 08:09:42 AM
post Re: Coulometric hourmeters
[Laboratories, Equipment and Tools]
davekni
June 30, 2024, 06:49:45 AM

Sitemap 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 
SimplePortal 2.3.6 © 2008-2014, SimplePortal