The rust is kind of inevitable while dealing with steel that doesn't get coated with anything. I work for a company that is basically an OEM for various things. Lots of our sub assembly parts have to be rushed to be powder coated during certain months because they will rust if we have stock lying around waiting to be sent out. Even just during a holiday break we had some output shafts from the gearboxes rust. We would have to take the units apart, machine the rusted shafts down, make special rollers to press fit onto the smaller shafts, and put it all back together. It was far cheaper to make a whole new set of non rusted shafts. It may have rusted during shipping over seas. We had a limited run of European units we had to make and they had all sorts of issues from the humidity in shipping.

A COLOR display that is SOFTWARE limited to MONOCHROME?!?! WTF has this world come to?

Another Sweet vid Dave! Thanks for being here!

I would love to see a teardown of a modern computer PSU (3.3, 5 and 12V ones)... There are plenty of detailed reviews around the net but nothing gets close to EEVblog level of detail.

Quote from LM4140 datasheet: "The mechanical stress due to the PCB's mechanical and thermal stress can cause an output voltage shift more than the true thermal coefficient of the device." When you're talking super high precision, bending the legs, and therefore the silicon, and therefore the silicon atom spacing, therefore the resistivity (just making things up here) can dominate other sources of error. The datasheet goes on to recommend a cutout in the board, just as seen in the video.

Nice video as always Dave.

Thanks, added datasheet link.

The faster the processor, the more critical the timing of the data being passed across parallel traces becomes. The 'twists' put in the traces is designed to make each of the traces in that collection electrically the same length. It is not at all unusual for those traces to be several clock cycles in length. Most processors can't handle bit 1 showing up on a different clock cycle than bit 7 of the same word.

SWEET! Good on ya Dave!!

True. It's nothing close to a commodity. Cheers for the insights, Dave!

Nicely done

Thank you. That explains a lot.

I love how you cut this warranty sticker BS !! It's a sacrilege I also do quite often and I enjoy it very much. It's like finding the Swiss virgins (the ones rubbing oil on screwdrivers) on a desert island !!

I thought I could see some rust (oxidisation) under the paint too. The metalwork is almost certainly not produced in the same factory as the boards, in fact there are probably a number of out-sourced companies supplying components which are just assembled in the Rigol factory so who knows how long or in what conditions the parts are stored in before final assembly. I know it's not very nice to see this in any equipment but it doesn't affect the performance or the warranty and won't get any worse

The test equipment industry is not a "volume" industry when compared to consumer stuff. And the higher up the food chain you go, the lower the volume. And the higher end gear has more R&D for that lesser volume, so the company needs to pay for that. Then eventually that top end technology filters down to the lower end gear. That's why the low end volume only cloners virtually never innovate and push the industry forward.

Yeah, It's probably just you. I find the "TT" highly interesting and its fun to see how different manufacturers do things! Keep it up Dave! :D

Nice to see you up well again. Since so many people think they have to abuse you, I have to say your Bolg is just very good. I enjoy every second of you videos. And I learn a lot out of them. Just give a crap on those who write stupid comments about your work. Keep on Dave! I have a lot of respect by watching your vids. Alex

Thanks very interesting video !

Yes, that's all part of the greater efficiency allowed by the toroidal construction.

Yay! New video!

great video, just starting to learn electronics in general and your teaching is captivating. how you get high pitched reminds me of stewie on family guy:)

also, welcome back

The main voltage reference seems to be the ADR381 (ADR381ARTZ) 2.5V reference IC. Just my $0.02

You sound a little better. Good for you. Thumbs up on the video.

Rust is usually on the sharp edges of the steel. That is most frustrating thing in my case, thats why i plan to put dehumidifier in my lab. Humidity must be 45% -/+5%.

what kind of adc/dac do they use?

Hi Dave, I have an old PC power supply i want to salvage all the parts from, now i don't know much about electronics but this is why i want to salvage the parts so i can have a play around with out spending anything. I just want to know what is the best way to drain all the power that may be left in the circuit and how to make sure afterwards?

What alternatives exist with similar features?

A few questions regarding the layout: why are the guard traces at 9:10 left without solder mask? And why are there seemingly unconnected vias all over the board? (22:34)

Yep, still very congested. Might take another week, which would make it almost a month now!

It's the same principle as last minute flights. You get the same product (a seat on the plane), but if you buy the day before you'll often pay twice as much. The expensive seats subsidise the cheap ones. But the cheap prices attract people to the company, and they look to it when they're in the market for the expensive product. Airline = last minute flight, Rigol = Precision PSU.

It's called Market segmentation. A very good, easy to read intro on this you can google "Camels And Rubber Duckies" by Joel Spolsky.

12:00 Software trimming? There is any tutorial about this? Because I'm building 1kW smps lab power supply and it will be very useful information for me. PS I also hate sticking to-220, HQ stuff and they dont want to put little piece of 1mm aluminium(lol, 0.1$?)...

As soldering goes, did you notice, ca. 9:17 the solder balls by C12? Like the routed slot around the voltage reference(s). Good practice. Those edges may not be very rusted yet, but they're on the way -- this thing is still pretty much factory fresh, right? Leave it out in some salt mist for a few days and then check on it!

also with torroids, windings have more surface area and are more spread out, so the windings dont tend to run as hot as a regular transformer

LOL, 'Duck's Gut's'! What make and model camera do you use to film with please? It has a nice output.

someone might have already asked this, but is it possible to just flash over the software for the 832a ? id love to see a video of that : )

Hey Dave, can you shoot a SHORT follow-up video with constant current mode performance? Something like set it to 10 V, 1 mA, attach a 10K resistor, oscilloscope, and then one more 10K in parallel. How fast will it go down to 5V?

Anyone know if the firmware keygen allows upgrade to to the SD832A model ?

I don't quite understand the purpose of the gap around voltage reference. Why thermal stress on the pcb will effect the voltage reference? or just want to keep the part away from the heat generated in the board

The processor board had a section labeled battery (test point) but I didn't see a battery anywhere on that board. Does the unit have a real time clock? You can see it at 22:09.

An other excellent teardown, thanks Dave! I'd love to know what those marked-out chips are..

Possibly. But I don't think I'd want that triangle display. Also, you might have to re-cal the unit perhaps?

Why are the tracks near the processor all curvy? Does it have to do with timing? Thanx.

13:23 What’s the reason of having those white coloured ugly stuff between the caps? For vibration protection? I did tear apart some units of all sorts. Always hated this when wanting to salvage the caps buried in between.

LOL ... half a bees 'what'!! (at 10:00 in) Nice description. :-) Appreciate the videos.

Device inside the iso route is ADR381ARTZ.

Could you not hack it so you can add sense inputs on the front/back seeing as the wiring is there for it? Couple of small 2mm banana jack on the front or something?

Dose the rigol use tapchanging from the transformer. Because I cant see any relays. So they need an huge heatsink and I woud use more than one TO247.

Another quirk of toroids is there is no sharp corner. In an E core the magnetic flux has to make a sharp 90 degree bend at each corner. In a toroid the flux makes a nice smooth circle.

Too late here in Greece (03:21) but i cant resist!! :-)

9:07 That looks to be a micro, ST logo peaking out of the lazer cut area. 4 core 1.2GHz with built-in 1Gbps ethernet with 4 port usb hub, turbos to 2.8 when lower then 38C.

I noticed that the main board is marked DP832, maybe they have a different board for the DP832A.

Up to 70 odd amps through TO220 legs? Are they sure?

I appreciate your criticisms of the products you tear down. I use these videos to try to learn from other's mistakes. So please! Be pedantic!

That´s why your computer mains is a Full primary Switch mode power supply. This unit is powered from a secondary SMPS...so the transformer is running at 50Hz AC....and this is make hin go big ;)

I love that physicists have given us a legitimate use for the phrase "flux efficiency"

What advantages does these classical transformer power supplies have over the more modern and lighter switched ones?

take care then !!

13:53 -- Dave refers to "huge number of Movs" protecting the input near the transformer. I'm a noob to electrical engineering godness, so would anyone mind letting me know what Mov(sp?) is? Thanks =)

Dave: How about some repair videos. I bought a scope and am sending it back as too much repair for a newby that has no idea how to even clean up the rotary switches! Thanks for the videos and please consider repair videos. Don

I'm not convinced they know what they're doing, that guard ring and cutout is a give away, it's almost like the thought it's a good idea to do it and did it based on the datasheet, there's not much precision to necessitate either

Hey Dave. I am a young electronics engineering student and I was actually wondering if you could PLEASE :') make a tutorial about PIC microcontroller programming using MPLab Ide and what Compiler you use. Please Please I am begging you. I really wanna learn.

They need to sell some units at higher prices to pay for the R&D. The choice is to sell units without features and with features, say 10,000 units at $800 and 1000 units at $1200, or they can sell all the units for $1000. $1000 would be the selling price if they just put all the features in. If most people don't need all those features, is it still a good deal that they're paying $200 for the stuff the don't need rather than 1/10th the number of people paying $400 for those features?

to make them not go so fast. If they were straight, the data would just "step on it" and in the next bend be too fast and fly off the wire and maybe hit the next wire. That's why they make it curvy so the data has to drive slowly and not go around the corners so fast.

E36313A Keysight, best power supply ever.

you can prevent the rust with stainless steel or paint

Why are some of the traces around the CPU so twisty?

Thanx. I knew they did that for HF but never seen it done for digital. I guess digital these days is also HF. ;-)

the nice thing with software crippling though is that it only takes one generous person to post their code online and everyone can use it on their machine i suppose

Gooood

I believe SamYoung is associated with United/Nippon Chemicon

It makes no sense to you because you are not in the business of selling these things. You make larger margins on higher end options to pay for the low margins you get on the base units. It all evens out and allows companies to invest back into R&D. If all companies just sold rock bottom margin gear, no one would have any money left to innovate. So they need a spread of gear to this, and software option is the most effective way to do that.

Those are pretty common, even from reputable suppliers, and from, say, ST, you get no choice in the matter, it's pot luck.

01:30 We can fix that :) LOL DAMN i really like your style!!! :) :) :)

Now I don't want to sound too negative, but Samyoung is the same brand crap caps that are used in the Samsung ccfl drivers and ALWAYS brake down after 2,5~3,5 years, so I would replace every single cap if I bought a PSU like this, but that is my professional opinion. I sell repair parts and every single work day I have 2 customers replacing Samyoung caps in Samsung TV's. Would not trust those, ever!

he turned it on in the last video :P

"Software limited to monochrome"? This is just hilarious :-)

στο προπροηγούμενο βίντεο του έλεγε καταλάθος συνέχεια Greece greek και κάτι τέτοια αν θυμάμαι σωστά. Μας τραβάει σιγά σιγά :P

If you want I might be able to send you some high quality audio amplifiers that have some really big toroidal transformers. If I do send you some they will be old and most likely not working. They could be good repair videos.

Well, the rust and the flux shouldn't be there, simple as that.

At the start of this video, I just wanted to push you aside to remove the lid myself.

warranty void? noooooooooooooo worries mate

LOL, 'Half a bee's dick', I missed that one!

WOW, it seem like you get a lot for your money. Only $400.00 not bad.

Unless you operate at sufficient volume perhaps, which these guys might not.

you mean Iike the rust case and korean caps aren't like rigol...

You sound much better. On the way to health.

it doesn´t....too bad ;)

** προπροηγούμενο mailbag **

don't turn it on, take it apart :D

Copy the software from the a, pop it on this. Free upgrades!

Why not sell the full version for less? Because they'd make less money, clearly. Why not get rid of the crippled version? Because the customers that would buy the crippled version would go elsewhere, and Rigol would make less money. Think of it the other way around, they could make truly different hardware instead of software crippling, and it would cost more to maintain the two different factory lines. Who wins? Noone. Economies of scale ftw.

A lot less noise

YESSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS!!!!!!

10:00 did he say "half a bee's dick"?? lol

PopCorn Time!

The most disappointing fact about this psu for me is definitely not the rust but the 1mF output cap. Definitely too much in my opinion.

xexe και Έλληνας και τέτοια ώρα! lol

Maybe I'm old-fasioned, but I can't get why do you need ethernet on a power supply. Nowdays you need ethernet on everything...