Author Topic: Glitchy Enertec 7150 ( Solartron / Schlumberger )  (Read 6989 times)

0 Members and 1 Guest are viewing this topic.

Offline jtu

  • Regular Contributor
  • *
  • Posts: 100
  • Country: lv
Re: Glitchy Enertec 7150 ( Solartron / Schlumberger )
« Reply #50 on: March 12, 2018, 06:25:59 pm »
Ok, it was couple hours of fun adding the ferrites :) No improvement thou.

You can take a look at some before/after pics here.

I had a hypothesis that maybe the problem occurs only during the warming up. Especially because unit is stable at least for days after it gets stable. But no, warming up did not eliminate the procedure of turning it on/off for several (like ~10) times before it gets stable.

I'm in need of the next hypothesis.
 

Offline Kleinstein

  • Super Contributor
  • ***
  • Posts: 7026
  • Country: de
Re: Glitchy Enertec 7150 ( Solartron / Schlumberger )
« Reply #51 on: March 13, 2018, 01:02:37 pm »
Individual ferrites to all inputs are unusual. The more normal type is having a single (maybe a second for rear terminals) large ferrite ring and all the wired going through. This would act as a common mode choke only. The individual ferrites could cause a little trouble in the current ranges in some applications. The individual chokes will still dampen common mode RF.  So the more common common mode choke would not give a much larger effect, just less side effect on the current measurement.

For the problem when turning on, one possible problem can be bistable relays. There are a few ways to handle the initial state - some methods may not be that reliable. The normal way would be switching them to the desired state - which is a good solution (though noisy), if there is enough delay for the power to stabilize.
 
The following users thanked this post: jtu

Offline jtu

  • Regular Contributor
  • *
  • Posts: 100
  • Country: lv
Re: Glitchy Enertec 7150 ( Solartron / Schlumberger )
« Reply #52 on: March 18, 2018, 02:51:36 pm »
For the problem when turning on, one possible problem can be bistable relays. There are a few ways to handle the initial state - some methods may not be that reliable. The normal way would be switching them to the desired state - which is a good solution (though noisy), if there is enough delay for the power to stabilize.

In the beginning of this discussion thread you kind of fought against relays as a cause for "Fail 1" ;) The symptom again is meter showing "Fail 1", just under another circumstances. But let's discuss it. Two questions:
- If we assume the meter is diagnosing the cause of the problem correctly, how bistable relays can cause data transmission line issue? The problem is repeatable this time, meaning relays do the same thing. What thing could it be?
- I don't get what you mean as a remedy in the last sentence. I'd google around, but could you give a bit more?
 

Offline Mickle T.

  • Frequent Contributor
  • **
  • Posts: 342
  • Country: ru
Re: Glitchy Enertec 7150 ( Solartron / Schlumberger )
« Reply #53 on: March 18, 2018, 03:09:09 pm »
I don't see any bistable relay in the 7150.
 

Offline jtu

  • Regular Contributor
  • *
  • Posts: 100
  • Country: lv
Re: Glitchy Enertec 7150 ( Solartron / Schlumberger )
« Reply #54 on: March 27, 2018, 09:22:23 am »
Just short update about interesting behaviour. This morning I got the meter working without restarting it several times. The differences from my usual power-on behaviour were two:
a) There was a DUT connected before power on. It was my DYI resistance standard connected via Kelvin leads. I kind of think I had done something like this previously, but can't really remember.
b) I did not use the meter's power on switch. I have another switch in the power extender. This type of power on I do not remember myself doing at any time.

This is in no way conclusive, I'll try to repeat this later.
« Last Edit: March 27, 2018, 02:00:32 pm by jtu »
 

Offline jtu

  • Regular Contributor
  • *
  • Posts: 100
  • Country: lv
Re: Glitchy Enertec 7150 ( Solartron / Schlumberger )
« Reply #55 on: April 01, 2018, 08:51:59 am »
No, this behaviour is not repeatable. That would be too easy, wouldn't it? :D
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf