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EEVBlog, the only RU-vidr I know who says 'A very quick video...' at the beginning of a 20 minute video... But somehow keeps me around for the entire time anyway...

I'm 14 and I learn so much from EEVblog I've learned ALL the basic parts to a circuit from you Dave! Greetings from North carolina!

A Chinese engineer I worked with said what a pcb LOOKS like is the most important criteria for Chinese management. They apparently don't usually care about much else, including the thermal design, as long as it looks "high quality" and similar to competing products. He said Chinese managers are rarely well educated in engineering and focused much more on the marketability of products, matching the most obvious features with the competition even if the features don't fully work, and they don't fix known problems unless they become a significant financial issue. If a product is bad enough it's sold off, rebadged If needed, and often marketed on eBay with essentially no usable warranty. They usually recover their investment even when the products are grossly flawed. Which, in turn, gives them little incentive to properly engineer anything.

Great job! And for RIGOL I have to say they are listening and try to improve! Thumps up! Credit to you Dave.

This was a common problem with some power supplies I was using back as a student. If we had a circuit with multiple input voltages but only 1 ground plane, we were always told to short the grounds on the supply together.

"Just a quick video" 20 minutes. I love it!!!!!

I noticed a few minor layout differences other than the lm317 you mention: 1> top right corner, different layout and one less small electro (between the 3 large ones, and the power devices above them) 2> a few minor component selection/layout differences on the bottom of the board, check the far right, and around the regulator on the left.

Hi Got my DP832 PSU today. I did buy it mostly based on the reviews here and thought most of the bugs would be resolved by now. But the OVP is a big FAIL. When I put a 12V lamp on output 1 and set the OVP on 12.5V. Then I put the output on 11.6V and turn the knob to jump from 11.6 to 12.6. The output first jumps to 12.6 stays there for 330ms and then turns off the output. But if I do the same with a jump from 11.6 to 21.6 the output stays on for a bit more than 500ms and then turns off. That is way too long and can fry your very expensive electronics just before turning off. So basically the OVP is only useful when the increment steps are small. The negative pulse on the 5V at switch on is still present. I have software version 1.14 and that is the latest one. They could simply resolve this in software by not allowing the voltage setting to increase over the OVP value wile in constant voltage mode. Instead they measure the voltage on the output and if that one goes above the OVP value is shuts the output of. That routine is slow so the output stays on for a long time. If OVP is on that routine should get a high priority. This is poorly designed software. Maybe a new followup?

I freaking like those videos. Keep up the good work Dave.

What about the overshooting voltage issue when switching on the channel? We should not forget that. Dave took apart this device for investigating this problem...

This all makes me think that Rigol's management system is poor from the top down. Ok, so some young designer was told to deal with the 5v supply and made a poor set of choices. However as Dave asks how did this pass muster and even get past first base? I wonder if any changes have happened at Rigol's management and product development stages. I also wonder what (if anything) would have happened if Dave had not flagged this to a global audience. Good on you Dave.

Thanks Dave, I was waiting for this follow up.

Thanks Dave, still not great. I was planning on buying one of these, won't now.

Dave, usually i agree on how you put a light on things.....but this time...IMHO this is *not* a "...killer precision power supply". (check it at 20:14) To be honest: NO A real -IMHO- killer PS would have: 1) Isolated and/or insulated grounds (=read individually) may with a switch to put them together if wanted but not by default. 2) No cap in the output after the regulator. 3) No resistors in ground path at all !!

Sounds like a trap for young players! Well spotted Dave and nice follow up!

Emona Instruments established by Alfred Brežnik. Nice to see Slovenian roots Down under. By the way, Emona was a roman city, right where Ljubljana - today's capital is.

15:20 Dave really trusts those cables :D. Although I agree with the inaccuracy, I doubt it's that big of a deal on this budget device

excellent job D.

Why they haven't just put that LM317 onto that medium-size plate radiator (in the center)? It could be easier and cheaper.

Love your videos buddy! Learned alot! Keep up the nice work :)

7:19: Two components between the new heat sink and the left edge (inverter + power resistor?) have been rotated 90° (lower left side of heat sink)...

i see a few little item changes maybe just locations they reduced the amount of caps middle rightfrom 2 to 1 wonder why less

You actually made them think.....COOL job!!

9:40 you do have pretty high mains to have upwards of 245-250v.. Then again, these sorts of machines will have quite some tolerances I can imagine. Having a trannie makes a device way less flexible, though. You'll see that switching PSUs can easily handle like 70-250v without any differences in output voltage. If this was Photoninduction's channel, he would certainly have hung this PSU on a variac to see if the issue was the higher voltage.. Like maybe this machine was made for 230v max and they're just stretching the limits for the Australian market. Anyway, even without variac, Dave's investigation is nice

In my opinion they should just get rid of the voltage regulator and put a BUCK AC2DC-Converter to it. 5V, 2A and on the input ~12V AC, 1A instead of converting all 10 Volts (DC is 15 Volts) to heat using this poor regulator...

I was holding off on this, now I will buy 1 and maybe 2 of them, good on Rigol for addressing the issue

Fan sounds lovely! Would you make a sleep aid video of it?

So it maxed out at around 80 degrees now. But what if it gets mounted into a rack with a higher ambient over 40 instead of the normal 21 room temperature?

I remember how I was told when I was a teenager: just put a power resistor between the transformer and the regulator :)

I'm loving the EEVBlog and forum, but I have a question for Dave, Since you so openly voided you warranty to look around inside in your teardown video, how did RIGOL replace and fix this (or any other piece of equipment)? How are you exempt from the infamous, warranty voided if removed label????????

Still don't understand why they didn't use something like the OKI-78SR series. By the time you add the larger heat sink the cost is not that much different.

Look at the bottom right where the two larger traces make two 45 degree angle changes there look to be differences.

I see an additional littte electrolyte capacitor on the right side, near some SOT-223 part.

What about an update to your's power supply designs?

missing one caps on the new board... below the SOT223 and above the right side of 3 large caps.

Have you seen this on Rigol DP831: "CH2 overcurrent protection, disable the output of CH2", but no output is on at all! Now the entire power supply is useless! I can't use any output since the error is constantly flashing "CH2 overcurrent protection, disable the output of CH2"! Any suggestions? Thanks for your videos and your help.

Something I'm confused about -- hope you don't mind if I ask. The model appears to be DP832, but it has a voltage and current resolution (in the digits) of 1mV and 1mA respectively, and I haven't seen that expect on the more expensive DP832A. Did your power supply get customized somehow?

No document? I'm surprised that they didn't used one of those cheap lm29.. dc-dc boards.

Thanks for video! I’m going to buy this PSU. How can I make sure that the PSU's top board has new revision? It's somehow indicated on the sticker? What’s the date of manufacture of your PSU? Sorry for my English.

Trying to decide if I want this unit. The only question I have is when the reset was happening and you had the board out, you also had all three channels on. But in the previous video you probed the temp without the channels on. I would think it would heat up more with all three channels on, or am I wrong about this? Just wondering if the reset happened with all three channels on, why wouldn't you probe it will the unit closed and air flow with all three channels on? And besides the one part failure you repaired, are you still using this PSU. The seiglint (spelling probably wrong) isn't an option based on the terminals bananas alone being miss spaced to use with my Pomona cables.

What alternatives exist with similar features?

I still can't get over how ugly that freaky keypad is!

Any news on updates done on recent units? I am on the fence between a Rigol DP832 or Sigilent SPD3303x

Why on EARTH did Rigol intentionally design in a hard, non-removable, non-switchable common between two of the three supplies? Haven't they ever heard of mixed-signal systems that need +15, -15 and +5V? Using this PS will, at best, throw digital noise from the 5V return onto the +15 supply! COMPLETE FAIL! Rigol, LISTEN UP! All 3 supplies should be completely isolated!

And I don't like the internal topology of this thing. Imagine you had it set on 30 Volts, then go down to 12, but the caps are still charged, then apply your load and some type of load will get a hughe bang... That's not a usable bench PSU...

I DESPISE ground current sensing on bench PSUs!

I already bought one unit after i saw your video and hope that the modification had been made 🤲what can i do if it is not done?!

they rearanged a few caps on the right I think.

THey changed the won hung low capacitors, too...Notice they are United Chemi-con now? Not the Sam Young :)

hey dave, im just wondering how do you still have the old board didnt you ship it back?

2:19 jet engine starting!

7:20 they changed the barcode sticker location too :P

Says very quick video, look at time, 20 minuets. Very Quick indeed. 0.o

4:47 nice fix they did, though

Hmmm... it's impossible to always return current to the proper ground. If I have a device, which has just one common ground and needs 2 voltages: +24 and +3 volts and I want to power it up from this supply. I have only a single wire to return current. Oops.

Why did they mess with the ground?? First of all the ground resistance in any ( =read every) PS should be as low as possible, or the user may ran into hum problems when using the PS in audio circuits. Next time, put the current sense drop resistor in the positive path (as usual) and you´re done.

If strapping the grounds together helps that much couldn't Rigol put a big jumper wire inside the PSU? Any downsides? It could be a quick fix until they get the chance to redesign the circuit.

someone might have got fired... oops!

lol i would love to be a sales person at lets say future shop and you come in with schematics to a new receiver they have and nick pick the design to death .would priceless. lol

OK so they aren't (mis)using the caps as heatsinks for a change... Good. But what about the power-on transient problem? any work on that? I really was looking forward for this ps, but with all those issues..

Is there a risk of shock from touching a bare sink while the system is live like that?

can be connected in parallel series mode for 60v or 30v 6a 3a?

130? :'D You gonna have to look that your transistor doesnt desolder itself! Liquid solder dripping out of your case, thats when you know your transistors got to hot!

is that really a solution... ? :|

Has anyone got there ruler yet in the USA I haven't got mine and can't email them BS thanx

The heat sink is still too small.

7:00 XD he burnt his finger

sounds like a jet reving up

Got to say, you’ve uncovered shoddy design as it typical with a lot of Chinese products. It comes down to “good enough” to pass off to a hobbyist however be very aware if you intend to use these for professional uses !! Current sense circuits should be galvanically isolated!!

What's a good electronics-based forum? Could anybody recommend one? I'd like to post some pictures of the insides of a power supply that I have, and get somebody more knowledgeable to look at it and assess it.

20:12 what do you mean "half-decent" ? there's nothing wrong with it after this fix, certainly not at its price point

I am thinking of buying this supply, should I really go ahead?

when I first seen them thin tab transistors. face palm come one cheep ass

you have two Fluke 87s ahhhhhhhhh!!!!!!

even at 53c is way to hot for me

Besides.....another User had been used (or better be forced) for beta testing.... A state whitch had to be done in th fab!

I think what we're seeing here is that rigol makes really crappy power supplies.

The chinese shouldn't be making expensive gear. They screw everything up!

Ya cant complain about a capacitor on the output FFS. My complaint wuold be the transformer in the first place. . . . This is the 21st century, have ya not heard of switch mode. . . . Should be switchmode with 30A output and half the weight and trouble. Linear regulators in this day and age, WTF is that. . . . Stone age.

why can't you clear your throat?