Author Topic: Did Rigol fix the DP832's "EEV Blog Fails"?  (Read 1359 times)

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Offline SpannersToSparks

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Did Rigol fix the DP832's "EEV Blog Fails"?
« on: January 26, 2017, 03:47:08 AM »
Hi

I am considering picking up the Rigol DP832, but watching Dave's series of videos on it put me off. Unfortunately, there doesn't seem to be much else in the same price bracket (£430 is about my max) of note. I'm not too keen buying second hand or refurbished, and if I can avoid buying off ebay, at least for my main PSU, I would rather do so.

Did Rigol fix the issues with the binding posts being on a common ground, and the inaccuracy of reported current? It looks fully featured but if I am spending that much on a piece of kit I hope to last a while, it would be reassuring to know there arent any problems before its even out the box.

Cheers
 

Online Silveruser

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Re: Did Rigol fix the DP832's "EEV Blog Fails"?
« Reply #1 on: January 26, 2017, 05:04:47 AM »
http://www.eevblog.com/forum/testgear/rigol-dp832-firmware-updates-and-bug-list/msg361709/#msg361709  Is the long thread of updates and fixes.

The common ground between ch 2 & 3 remains and is explained in a note. It should not be a problem if you are aware of it and connect everything correctly. Unless you need three totally independent  channels, then yes it is a problem/
 
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Offline rstofer

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Re: Did Rigol fix the DP832's "EEV Blog Fails"?
« Reply #2 on: January 26, 2017, 07:35:04 AM »
http://www.eevblog.com/forum/testgear/rigol-dp832-firmware-updates-and-bug-list/msg361709/#msg361709  Is the long thread of updates and fixes.

The common ground between ch 2 & 3 remains and is explained in a note. It should not be a problem if you are aware of it and connect everything correctly. Unless you need three totally independent  channels, then yes it is a problem/

So, if you want +-15v and +5V, Ch1 MUST be the negative supply (because it doesn't have a common ground), Ch2 MUST be the positive supply and Ch3 will be the +5V supply.

Not a big deal. Rigol has an app note on how to properly connect the supplies.

For what I do, op amps and logic, the common ground is not an issue.  YMMV...
 
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Offline 2N3055

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Re: Did Rigol fix the DP832's "EEV Blog Fails"?
« Reply #3 on: January 26, 2017, 07:52:09 AM »
If you need dual +-30V and separate 5V than you have DP831 for that... DP831 has channels connected differently..  +-30V have common ground , 0-8V channel is isolated...
That is why I didn't buy DP832 but instead got DP831...  No problems with the channels at all..
 
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Offline SpannersToSparks

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Re: Did Rigol fix the DP832's "EEV Blog Fails"?
« Reply #4 on: January 26, 2017, 07:56:32 AM »
OK thanks chaps, looks like the Rigol is back on the table for consideration.
 

Offline SpannersToSparks

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Re: Did Rigol fix the DP832's "EEV Blog Fails"?
« Reply #5 on: January 26, 2017, 08:04:54 AM »
OK thanks chaps, looks like the Rigol is back on the table for consideration.

Yeah I spotted that on the Rigol site. I am still learning, so can you explain why the 831 has a -30 and a +30, and what the difference is to the 832 with 2 x +30?

I'm a mechie by trade and we're a bit of a slow breed  :horse:

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Online tggzzz

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Re: Did Rigol fix the DP832's "EEV Blog Fails"?
« Reply #6 on: January 26, 2017, 08:06:54 AM »
I am considering picking up the Rigol DP832, but watching Dave's series of videos on it put me off. Unfortunately, there doesn't seem to be much else in the same price bracket (£430 is about my max) of note. I'm not too keen buying second hand or refurbished, and if I can avoid buying off ebay, at least for my main PSU, I would rather do so.

For a simple non-programmable linear PSU, I pick up old Farnells for £10-£20 at local auctions.  I put a 300W resistor across the outputs to test it.

The worst I've had to do is change a capacitor and deoxidise some pots. Cost: ~£60.

Now, what do I want to buy with the other £350? Of course, you may place a significant value on your time ;)
There are lies, damned lies, statistics - and ADC/DAC specs.
Gliding aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
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Offline 2N3055

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Re: Did Rigol fix the DP832's "EEV Blog Fails"?
« Reply #7 on: January 26, 2017, 08:51:06 AM »
OK thanks chaps, looks like the Rigol is back on the table for consideration.

Yeah I spotted that on the Rigol site. I am still learning, so can you explain why the 831 has a -30 and a +30, and what the difference is to the 832 with 2 x +30?

I'm a mechie by trade and we're a bit of a slow breed  :horse:

Cheers

No worry mate, glad to help..

When you have 3 channels that are completely isolated, you can connect them in any parallel or serial combination... In reality that is best combination..

DP831 has two 30V channels connected in series, with middle connection being ground and separate 8V channel: 
separate (+)--8V--(-)  and  (+)--30V--(GND)--30--(-) 

DP832 has one 30V channel connected with common ground with 5V channel,and separate 30V channel:
separate  (+)--30V--(-)  and    (+)--30V--(GND)--5V--(-)   
 
If you need more than 30V then you connect two channels in series for 60V... DP831 already has that connected.. But you can't connect two 30V channels in parallel to get 30V and double the current..

On DP832 you can connect 30V channels in series and parallel..
But on DP832 you can't have +- dual 30V supply AND 5V have common ground... And that is combination I use... I use +-15V for opamps and 3-5V for logic circuits on a same board with common ground... I can also route analog and digital grounds separately and connect them at the board at proper place in circuit..

Since that's the kind of stuff I do, I bought DP831... I also have two cheap linear 30V/3A PSU that I can use for crazy combinations... Those together work very well for me..  I also like that "logic supply" channel goes to 8V and 5A... That is good for testing logic supplies to max specs, and also I usually need more current for logic...
On bad side, DP831 has only 2A on 30V channels.. But I have other supplies for that if I need...

So, like all instruments and tools... Tools for the job... DP831 is perfect for me, DP832 not so much.. But you need to find what you need..

Take care !



 

Offline rstofer

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Re: Did Rigol fix the DP832's "EEV Blog Fails"?
« Reply #8 on: January 26, 2017, 09:06:48 AM »
On DP832 you can connect 30V channels in series and parallel..
But on DP832 you can't have +- dual 30V supply AND 5V have common ground... And that is combination I use... I use +-15V for opamps and 3-5V for logic circuits on a same board with common ground... I can also route analog and digital grounds separately and connect them at the board at proper place in circuit..

Since that's the kind of stuff I do, I bought DP831... I also have two cheap linear 30V/3A PSU that I can use for crazy combinations... Those together work very well for me..  I also like that "logic supply" channel goes to 8V and 5A... That is good for testing logic supplies to max specs, and also I usually need more current for logic...
On bad side, DP831 has only 2A on 30V channels.. But I have other supplies for that if I need...

So, like all instruments and tools... Tools for the job... DP831 is perfect for me, DP832 not so much.. But you need to find what you need..

Take care !

For the 832, the (-) side of Ch2 and tied to the (-) side of Ch3 so call that ground.  Now I have +30 and +5 relative to the common ground.  Then connect the (+) side of Ch1 to the common ground and, voila', I have a -30V supply.  Of course, I would have both 30V supplies cranked down to 15V for op amp work.

It takes a little remembering that Ch1 will be the negative supply.  That bit isn't intuitive until you think it through.

 

Offline 2N3055

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Re: Did Rigol fix the DP832's "EEV Blog Fails"?
« Reply #9 on: January 26, 2017, 09:16:14 AM »

For the 832, the (-) side of Ch2 and tied to the (-) side of Ch3 so call that ground.  Now I have +30 and +5 relative to the common ground.  Then connect the (+) side of Ch1 to the common ground and, voila', I have a -30V supply.  Of course, I would have both 30V supplies cranked down to 15V for op amp work.

It takes a little remembering that Ch1 will be the negative supply.  That bit isn't intuitive until you think it through.

No, you're right, I didn't see right how 30V channel is connected to 5V channel.. They are not in series but have common (-)..
So logically you can connect other 30V channel in negative direction..

But  DP831 has no current shunt share problem and is already in config I use it most of the time, so I chose DP831....
For other combinations I just combine with other PSU-s..

Thank you for setting me straight.. I appreciate it!!

Take care!

 

Offline SpannersToSparks

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Re: Did Rigol fix the DP832's "EEV Blog Fails"?
« Reply #10 on: February 09, 2017, 05:37:46 AM »
Hi chaps

What do you all make of this? https://www.amazon.co.uk/High-Precision-Adjustable-KORAD-Supply-KA3005D/dp/B0084JFWNY/ref=sr_1_fkmr0_1?s=diy&ie=UTF8&qid=1486578714&sr=1-1-fkmr0&keywords=Korad+KA3005P

It was reviewed by EEV blog and after a false start, declared a winner. Do you think I could get away with buying two of these and use them for The Art Of Electronics student course? (Digital and Analog parts). Or maybe buy one at first, then get a second if its really needed? I Also need to pick up a function generator, components, bread boards etc etc etc

Random thought: The problem with buying stuff for a course of learning is that you need to have taken the course of learning to really know what you needed to buy in the first place...  :wtf:
 

Offline rstofer

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Re: Did Rigol fix the DP832's "EEV Blog Fails"?
« Reply #11 on: February 09, 2017, 05:50:17 AM »
Hi chaps

What do you all make of this? https://www.amazon.co.uk/High-Precision-Adjustable-KORAD-Supply-KA3005D/dp/B0084JFWNY/ref=sr_1_fkmr0_1?s=diy&ie=UTF8&qid=1486578714&sr=1-1-fkmr0&keywords=Korad+KA3005P

It was reviewed by EEV blog and after a false start, declared a winner. Do you think I could get away with buying two of these and use them for The Art Of Electronics student course? (Digital and Analog parts). Or maybe buy one at first, then get a second if its really needed? I Also need to pick up a function generator, components, bread boards etc etc etc

Random thought: The problem with buying stuff for a course of learning is that you need to have taken the course of learning to really know what you needed to buy in the first place...  :wtf:

You can certainly use this single output supply but...  One of the things the Rigol 832 has is a common Output ON/OFF button.  All 3 supplies are turned on and off together.  It seems to me that this is important but maybe not.  I would certainly want to shut off the op amps before I shut off the uC or at least turn them off together.  I wouldn't want the op amp supplies feeding through the uC ADC and potentially trying to power the uC.  That kind of thing...

 


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