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.
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.
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.
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
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 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.
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!
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 !!
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.
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.
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.
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
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:)
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)
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?
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.
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$?)...
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.
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%.
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
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?
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 ;)
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?
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.
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
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.
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 =)
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?
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.
i think it makes a little inductor ,which is need to run the cpu,or making the traces have other impedances to act as a diy resistor.It depents on the cpu itself . *Note : This is my opinion,i am not saying its true ,but it could be* ,have a nice day
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.
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.
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.
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!
[revising my statement] yeah but that power supply does not give anywhere near the control and quality this unit provides. You are comparing two completely different regulation systems. SMPS vs Linear!
Hmm, why do they cripple the software on some of their products and sell them for less? Couldn't they just Sell the full version for less, or get rid of the crippled version and just sell the full version? To me, selling the same unit with dumber software, makes no sense. Production of both units cost the same, so what's the point?
Maybe if it's in some industrial setup, but then, usually, the supply is fixed. I don't know, I can live with theese computerised things until they stop working without an I-phone....
hdagelic I know I'm a bit late but anyhow: I also greatly appreciate ethernet jacks on my instruments. We do most of our product testing via scripts that control our instruments for regression test / schmoos / etc. It's also kinda nice if you can setup a few instruments for a specific test by running one script etc. When you want/need this Ethernet is a good interface...GPIB is pretty klunky (especially the old cables) and for USB you often need special drivers etc.
I just worked recently on a setup used to test medical grade circuit boards that cost tens of thousands a board. We use the supply's ethernet port to verify that the voltages and limits are set correctly before anything is powered. We don't want to start blowing up expensive boards because someone bumped the controls.
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.
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.
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.
Thanks, added datasheet link.
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
Nice video as always Dave.
A COLOR display that is SOFTWARE limited to MONOCHROME?!?!
WTF has this world come to?
Training people to pay for software as they used to pay for hardware
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
True. It's nothing close to a commodity. Cheers for the insights, Dave!
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.
Dave knows
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!
Yes, that's all part of the greater efficiency allowed by the toroidal construction.
Possibly. But I don't think I'd want that triangle display. Also, you might have to re-cal the unit perhaps?
Yep, still very congested. Might take another week, which would make it almost a month now!
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
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 !!
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.
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.
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.
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
I love that physicists have given us a legitimate use for the phrase "flux efficiency"
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
An other excellent teardown, thanks Dave! I'd love to know what those marked-out chips are..
Has anyone figured out what those chips are yet?
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:)
Device inside the iso route is ADR381ARTZ.
SWEET! Good on ya Dave!!
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.
They do tsp chsnging with triacs
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)
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?
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.
You sound a little better. Good for you. Thumbs up on the video.
The main voltage reference seems to be the ADR381 (ADR381ARTZ) 2.5V reference IC.
Just my $0.02
12:00 Software trimming?
There is any tutorial about this?
Because I'm building 1kW smps lab power supply and it will be very useful information for me.
PS I also hate sticking to-220, HQ stuff and they dont want to put little piece of 1mm aluminium(lol, 0.1$?)...
also, welcome back
It's called Market segmentation. A very good, easy to read intro on this you can google "Camels And Rubber Duckies" by Joel Spolsky.
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.
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%.
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
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?
Why are the tracks near the processor all curvy? Does it have to do with timing? Thanx.
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 ;)
Up to 70 odd amps through TO220 legs? Are they sure?
TheRomanceOfMachines That's what I think when the tiny SMT MOSFETs say they can handle hundreds
I noticed that the main board is marked DP832, maybe they have a different board for the DP832A.
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?
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.
Nicely done
What advantages does these classical transformer power supplies have over the more modern and lighter switched ones?
Less noisy power.
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 : )
Too late here in Greece (03:21) but i cant resist!! :-)
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
LOL ... half a bees 'what'!! (at 10:00 in) Nice description. :-) Appreciate the videos.
LOL, 'Duck's Gut's'! What make and model camera do you use to film with please? It has a nice output.
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.
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 =)
MOV = Metal-oxide Varistor. en.wikipedia.org/wiki/Varistor
gamlinlarsen ah -- much appreciated =)
Anyone know if the firmware keygen allows upgrade to to the SD832A model ?
Yay! New video!
What alternatives exist with similar features?
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?
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!
Thank you. That explains a lot.
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.
I believe SamYoung is associated with United/Nippon Chemicon
what kind of adc/dac do they use?
you can prevent the rust with stainless steel or paint
Why are some of the traces around the CPU so twisty?
i think it makes a little inductor ,which is need to run the cpu,or making the traces have other impedances to act as a diy resistor.It depents on the cpu itself . *Note : This is my opinion,i am not saying its true ,but it could be* ,have a nice day
May be for the equal lenght data busses.
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.
στο προπροηγούμενο βίντεο του έλεγε καταλάθος συνέχεια Greece greek και κάτι τέτοια αν θυμάμαι σωστά. Μας τραβάει σιγά σιγά :P
E36313A Keysight, best power supply ever.
Thanks very interesting video !
Those are pretty common, even from reputable suppliers, and from, say, ST, you get no choice in the matter, it's pot luck.
take care then !!
Thanx. I knew they did that for HF but never seen it done for digital. I guess digital these days is also HF. ;-)
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.
"Software limited to monochrome"? This is just hilarious :-)
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.
warranty void? noooooooooooooo worries mate
Unless you operate at sufficient volume perhaps, which these guys might not.
he turned it on in the last video :P
Gooood
you mean Iike the rust case and korean caps aren't like rigol...
WOW, it seem like you get a lot for your money. Only $400.00 not bad.
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.
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!
01:30 We can fix that :) LOL DAMN i really like your style!!! :) :) :)
LOL, 'Half a bee's dick', I missed that one!
Copy the software from the a, pop it on this. Free upgrades!
** προπροηγούμενο mailbag **
You sound much better. On the way to health.
[revising my statement] yeah but that power supply does not give anywhere near the control and quality this unit provides. You are comparing two completely different regulation systems. SMPS vs Linear!
don't turn it on, take it apart :D
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.
Hmm, why do they cripple the software on some of their products and sell them for less? Couldn't they just Sell the full version for less, or get rid of the crippled version and just sell the full version? To me, selling the same unit with dumber software, makes no sense. Production of both units cost the same, so what's the point?
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...
Maybe if it's in some industrial setup, but then, usually, the supply is fixed. I don't know, I can live with theese computerised things until they stop working without an I-phone....
hdagelic I know I'm a bit late but anyhow: I also greatly appreciate ethernet jacks on my instruments. We do most of our product testing via scripts that control our instruments for regression test / schmoos / etc. It's also kinda nice if you can setup a few instruments for a specific test by running one script etc. When you want/need this Ethernet is a good interface...GPIB is pretty klunky (especially the old cables) and for USB you often need special drivers etc.
I just worked recently on a setup used to test medical grade circuit boards that cost tens of thousands a board. We use the supply's ethernet port to verify that the voltages and limits are set correctly before anything is powered. We don't want to start blowing up expensive boards because someone bumped the controls.
It's not expensive today to add ethernet capability and it's really useful.
Ethernet is handy, why run USB or serial to a PC when you can just plug the device straight into your network switch?
YESSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS!!!!!!
10:00 did he say "half a bee's dick"?? lol
Lol yep.
A lot less noise
it doesn´t....too bad ;)