Author Topic: EEVblog #512 - Rigol DP832 Bad Design Investigation  (Read 254382 times)

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Offline Rigby

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #625 on: August 28, 2014, 06:47:11 pm »
oh wow. 

nicely done spotting those and fixing them.  replace that single-use fuse with a polyfuse.
 

Offline f1rmb

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #626 on: August 28, 2014, 08:20:48 pm »
Thanks  :D


Yes, polyfuse sounds good. Lets check Farnell and RS.


Cheers.
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Daniel
 

Offline saturation

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #627 on: August 28, 2014, 08:54:04 pm »
Great find  :phew:, and good job  :clap:.  Naturally, it makes one now wonder about Rigol's quality control.  What does this fuse protect?  Is it to power the main board(s)?


Hi,

    Okay, problem found and fixed.
For test purpose, I temporary straped the fuse, and the channel is working again. Now I need to find a replacement.
Best Wishes,

 Saturation
 

Offline f1rmb

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #628 on: August 28, 2014, 10:39:31 pm »
Great find  :phew:, and good job  :clap:.  Naturally, it makes one now wonder about Rigol's quality control.  What does this fuse protect?  Is it to power the main board(s)?

Thanks. Lead free solder is really a PITA. Otherwise the build quality is nice, IMHO (except the LM317 stuff, even with larger heat sink).

This fuse is in the channel 1 AC input line.

Cheers.
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Daniel
 

Offline Rigby

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #629 on: August 28, 2014, 11:08:28 pm »
That LM317 should have been a switching regulator from the beginning. 

Leaded solder isn't too bad once you get used to it. 
 

Offline mcinque

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #630 on: August 29, 2014, 12:56:36 pm »
Naturally, it makes one now wonder about Rigol's quality control.

EVERY product can have a trouble like that.
Do you think RIGOL checks every-single-PSU? At that price? You're kidding...

They probably calibrate the boards by using pogopins and not the completed PSUs, so this can explain the issue.
I'm basically still a rookie and because of this, even with the best intentions, I often say bullshits
 

Offline saturation

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #631 on: August 29, 2014, 02:57:30 pm »
Yes they should.  Proper QC can be fully automated.   The market for T&M is small, so reputation particularly among people who can examine the interiors and truly appreciate poor design or workmanship, makes it even more important they are strict with QC.  Burn testing this PSU then scanning the PCB with a thermal camera could have revealed the fuse was about to blow.

The fault mentioned here looks like either the one part was faulty and is an easy fix, or there is another fault downstream that blew the fuse,  so one has to check for it after the fuse repair.


EVERY product can have a trouble like that.
Do you think RIGOL checks every-single-PSU? At that price? You're kidding...
Best Wishes,

 Saturation
 

Offline mcinque

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #632 on: August 29, 2014, 03:12:04 pm »
Yes they should.

I agree, but at that price you get a TRIPLE OUTPUT, very accurate, low ripple programmable PSU that costs much, much less than any other PSU... There is no comparison with other PSUs on the market at the moment.

I think it's a compromise.
I'm basically still a rookie and because of this, even with the best intentions, I often say bullshits
 

Offline f1rmb

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #633 on: September 23, 2014, 09:20:34 am »
Hi,

    Since I don't want to crosspost, here https://www.eevblog.com/forum/testgear/rigol-dp832-firmware-updates-and-bug-list/msg518001/#msg518001 is the first informations of the new top board I just received (pictures to come).

BTW, if you want to see the pictures here instead, just let me know.

Cheers.
---
Daniel.
 

Offline f1rmb

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #634 on: September 23, 2014, 03:24:43 pm »
 

Offline pascal_sweden

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #635 on: October 21, 2014, 05:41:24 pm »
Are all the issues fixed now on the Rigol DP832? Or which issues are still present in the last revision?

Do the units still suffer from overshoot? Or can I leave the PSU connected to my target board without risking my design to get destroyed?

When will Rigol make a version where all (-) are isolated and not two common?
Do they actually have this in higher-end models or do they always share two (-) in common?

The Rigol DP832 would be a nice replacement to Philips PE1542, if it does not have the overshoot, and if it would have 3 completely isolated outputs.
 

Offline akkarin

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #636 on: December 02, 2014, 11:37:11 am »
I would also be interested which issues are still present in the latest revision.
Foremost I would like to know if the fan is still that noisy.


I am currently in the market for a new and better PSU and the DP832 could be "the one". But I hate noisy equipment I like it almost silence on my bench. Does not have to be super silent whatsoever but I once heard the DP832 and thats too loud for my ears. ;)

Anyway some update would be nice if someone has some news.
 

Offline mcinque

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #637 on: December 02, 2014, 12:25:56 pm »
Do the units still suffer from overshoot? Or can I leave the PSU connected to my target board without risking my design to get destroyed?

It's not a Rigol's PSU issue. Most PSUs has overshoot at power on. I have a TTi and it behave almost identical. IMO you should never leave your circuit connected (without a properly designed input) when powering on a bench PSU.

I'm basically still a rookie and because of this, even with the best intentions, I often say bullshits
 

Offline Rigby

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #638 on: December 03, 2014, 03:31:00 am »
So I think one could pretty easily mod the 832 to use a quieter fan, though mine does drive the fan according to load just fine.

If you were to use a couple temp sensors you could keep it to a very quiet idle until something heated up, and let a PID loop handle the fan for ya.
« Last Edit: December 04, 2014, 08:57:00 pm by Rigby »
 

Offline Gallymimus

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #639 on: December 04, 2014, 08:53:37 pm »
That LM317 should have been a switching regulator from the beginning. 

Leaded solder isn't too bad once you get used to it.

That would be incorrect.  It is foolish to use a switching regulator for control circuitry IF you want low noise.  A linear regulator was likely the right choice (again assuming it is powering the DACs ADCs and signal amps)
 

Offline Monkeh

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #640 on: December 04, 2014, 08:55:28 pm »
That LM317 should have been a switching regulator from the beginning. 

Leaded solder isn't too bad once you get used to it.

That would be incorrect.  It is foolish to use a switching regulator for control circuitry IF you want low noise.  A linear regulator was likely the right choice (again assuming it is powering the DACs ADCs and signal amps)

I strongly doubt it's powering anything of the sort.
 

Offline Rigby

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #641 on: December 04, 2014, 08:56:23 pm »
As do I.  Looks to me like it's driving the front panel only.  I haven't opened it up and looked in a while, though.
 

Offline MattFL

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #642 on: November 06, 2015, 07:18:58 pm »
Not to druge up an old topic, but I'm shopping one of these and would love to hear from anyone who has purchased one recently if there are any issues with the revision that is currently for sale? 
 

Offline Howardlong

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #643 on: November 06, 2015, 08:08:45 pm »
Not to druge up an old topic, but I'm shopping one of these and would love to hear from anyone who has purchased one recently if there are any issues with the revision that is currently for sale?

As far as I am aware, all outstanding bugs I'm aware of were resolved at firmware release 1.14. Happy to be corrected of course, Rigol has a reputation for having several different hardware versions of boards, and the regression testing matrix doesn't always seem to be completed across all combinations.
 

Offline neslekkim

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #644 on: November 06, 2015, 11:20:47 pm »
anyone know information about serialnumbers and when they are produced?
I got my 832A unit today with serialnumber DP8B17***
 

Offline Teneyes

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #645 on: November 07, 2015, 04:11:37 am »
anyone know information about serialnumbers and when they are produced?
I got my 832A unit today with serialnumber DP8B17***
rigol uses the 1st 2 digit after model "DP8B" as the year of production since 1998 . So the 17 is 2015. The next 2 digits is the week in the year of production 01-52 then serial number , I think last 5 are sequential for the model
IiIiIiIiIi  --  curiosity killed the cat but, satisfaction brought it back
 

Offline neslekkim

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #646 on: November 07, 2015, 07:46:01 am »

Ah, so week six then, second week of february?
DP8B1706xxxxx
 

Offline rs20

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #647 on: November 07, 2015, 07:57:24 am »
rigol uses the 1st 2 digit after model "DP8B" as the year of production since 1998 . So the 17 is 2015. The next 2 digits is the week in the year of production 01-52 then serial number , I think last 5 are sequential for the model

Wat.. mine is DP8C1524xxxxx. I wonder what the C means? Can't be a newer revision, mine is dated 2013, which sounds about right.
 

Offline neslekkim

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #648 on: November 07, 2015, 08:52:29 am »
The dp831a that I got sent wrong instead of the dp832a had DP8A1520xxxxx
 

Offline Stupid Beard

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Re: EEVblog #512 - Rigol DP832 Bad Design Investigation
« Reply #649 on: November 07, 2015, 09:13:36 am »
rigol uses the 1st 2 digit after model "DP8B" as the year of production since 1998 . So the 17 is 2015. The next 2 digits is the week in the year of production 01-52 then serial number , I think last 5 are sequential for the model

Wat.. mine is DP8C1524xxxxx. I wonder what the C means? Can't be a newer revision, mine is dated 2013, which sounds about right.

Mine is DP8C as well (from end of 2014) and is a plain non-A unit. neslekkim's is a DP832A, hence the different serial number prefix.
 


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