EEVblog 1561 - µSupply USB Power Supply - Part 21

[@nezbrun872]

You're right about USB type C PD, just like USB itself, it's a bitch of a standard. I'm working on a project that negotiates from first principles, using sub $ MCUs that are now available with enough on chip to do the PHY for PD, including opamps, comparators, CRC. Everything about PD is hard work, from the wire through the software stack and seemingly endless state machines. The state machines interact with each other too under abnormal conditions, it's a bit like having a goto in code. Just choosing a regulator and voltage domains is hard work for PD UFP, it needs to be able to function from 3.3V to 20V, and you need to be able to protect the CC1 & CC2 lines. You could do a whole series of videos on USB PD,

[@EEVblog]

Yeah, that's why we abandoned using the primary side ST micro to do it all natively. Ended up being simpler and cheaper to use a smaller ST micro and use an OTS USB-PD controller. But it can pay if you need the big beafy micro for other stuff.

[@petegaslondon]

Good GRIEF .. Gimme me old concentric connector back! Just need ONE protection diode, and something for over voltage Unless someoens integrated these functions in a readily available piece of silicon???

[@marvingudel605]

Just recently had a look in to the USB 3 spec and oh man, these state machines! There are really some wild diagrams in there.

[@Ariccio123]

​@@petegaslondonI dunno, I go back and forth mentally. Both as a consumer, and as a very very occasional person choosing to power something somehow. The old fashioned barrel jacks were real dead simple, and had few things that could go wrong. But also, sometimes, I screw up. So many different devices, all look the same and fit together, with totally different voltage and power requirements. The hassle of USB-c on the design-end absolutely seems worth it when it comes to be able to just arbitrarily connect power between whatever devices I want to connect. A few years ago my dad left his laptop charger at home while traveling. We were able to slowly charge it overnight from a 5v-capable USB-c phone charger. Even though the laptop normally *wanted* 12v to charge. It was degraded functionality, but it *worked*. That's just so incredibly valuable. To think I can just get *power* out of anything USB-c and into anything USB-c is so damn useful in an almost childlike way.

[@Destructificial]

Do you happen to have a public repo somewhere? I have been thinking about doing something similar for AGES, but especially the PHY part is a bit of a nightmare with all the analog stuff going on.

[@sabamacx]

Prior to starting engineering studies, this project was *the* thing that got me into eevblog and critical to my interest in EE. The promise of a whole EE design from concept to execution and mass manufacture was *the* highlight of subscribing to EEVblog. I'd still buy this supply in a heartbeat.

[@YashKudale]

I agree no content like this, I mean there are now. Also very few are such polished product intended for market. Learnt a lot.

[@RandyLott]

I've been watching since before Sagan and when you were in the garage (actually saw the hazmat video on Altzone). I've learned so much from this channel and I believe the success of my career has been partially due to you (enthusiasm, curiosity, information, creativity). Since I first started watching, I've designed high voltage fluid charging/deflection for cell sorters, satellite thruster power supplies, infrared cameras, laser systems, and cutting edge space electronics. Thank you for everything! You've inspired and educated so many people.

[@EEVblog]

Glad to hear, thanks! Wow, the hazmat video.

[@chongli297]

I dunno about everybody else, but I could watch endless videos of power supply design. It's an amazing rabbithole!

[@ryebis]

It's a very nice elegant design, going to be a tough sell though unless priced competitively. One of those passion projects in which the process and journey provides more joy than the commercial outcomes 😄

[@NoLandMandi]

Wow! At last! Very happy to see this little guy still kicking!

[@SeanBZA]

Keep the isolation, will make it easier to keep noise down. Plus you can get cheap DC DC converter IC's that run at 1MHz plus, so you can easily get the 12W plus through the transformer, with a driver the size of a flea. PD controller, 3V3 regulator that can handle 12V or higher on input, and then a 3V3 simple USB isolated interface, to pass USB over to the chip handling display to allow USB control over the USB side of the USB C port. Keep it to one grunty micro on the isolated side, which was chosen to handle display directly, and let it do all the work.

[@ag.cousins]

The noise reduced from isolation will be foreshadowed by the 1MHz converter!

[@mr.jimmydean1980]

Finally, the video I've been waiting for all these years... I'd love to see the stages of it.

[@kylerkidd4834]

I designed something like this when I was inspired by the old school uSupply and learned so much along the way. Thanks for showing off

[@Willy_Tepes]

Projects are fun and you learn a lot from them. Getting to the end is not always that important. I've been working on my own project for 4 years because I had to do everything myself, but I will be sending you a sample when I finish it around Christmas time this year Dave. It's a DIY kit with some cool features.

[@zyghom]

I totally agree: very often the project as a target is irrelevant - the way to the target is more important. What you learned what you experienced might be much more valuable than the end product.

[@jj74qformerlyjailbreak3]

I didn’t even know you were designing this. All the videos you have it don’t surprise me. I also have spent documentable time to the subject of USB power supplies. I really want a Bluetooth middleman or even usb middleman for one hub all usb and Bluetooth WiFi console environment to set hosting values and management to share devices with hardware not supported by a particular device. This was the intention of going down the road of electronics design and will be a product before I die. Thanks for all you do for the community.

[@badarjahangirkayani6196]

I got inspired by this the last time I saw it and made a quick and simply contraption with a USB-PD board and a Ruideng Tech DPS3003 power supply module. Not as sleek as your solution but does the job. I think if you sell the screen, case and banana jack, people would love to take the challenge of designing their own circuits for it. Could even be a competition or something for the best design.

[@villehietala9677]

I made couple power supplys with similar chinesium ps modules. One has 3x 18650 in it and 30V/4A/50W max output. Second one has banana plugs as input and i made a makita battery adapter for it from a chinese clone of makita usb-adapter. That one has 50V/5A/180W max out with one 18V makita battery and with >30V could go up to 250W. Those things have saved me several times as an electrician. Testing led-lights, troubleshooting 0-10v building automation stuff, driving smoke extract windows, tracing ground leaks with clamp meter etc. The larger one has bluetooth module in it, which helped a lot when i had to check which cable goes to which fire damper in a hvac system, as those ~60 cables had just a running number on them and those numbers did not match with the actual devices and no one seemed to know where they went. Bluetooth gave me 15-20 meters more of a head start, as i killed the power to the damper by phone and could hear where the spring loaded damper winded to closed position. I've been planning to make yet another one with internal batteries for just a little bit higher specs. That small one won't drive the largest smoke extract windows and having an external battery while slipping on a roof with other tools wont make the job any easier.

[@seppeon]

Hello, I am David2! This was a wonderful, fun and educational project and in complete agreement! USB-PD really was a surprise in complexity and I completely agree, isolation was a giant pain! It was the primary source of inefficiency too, may have even been worse for efficiency than the output regulator! That funny circuit that you were not sure what it does (kzbin.info/www/bejne/fHymZ5-kibB7Y8U), I believe its a ripple blocker, but don't quite remember. The switching regulators had some noise which coupled through op-amps due to their power supply rejection ratio not being massive. Iirc, there were options of higher performance op-amps, but you pay for that too. I believe that rough simulation will show some ripple blocking :) That battery prototype was indeed a negative bias!

[@Ghostpalace]

This is the type of videos that are amazing to watch. Id love to have a gadget like this in my toolbag

[@Hasitier]

Yes Dave. I would love to see more details and the history of this little supply. As you might know I watch your channels since years beginning from the Garage time. And I would buy one if it would become a product.

[@stevedaenginerd]

Second this! I think it'd be interesting to walk thru all the different iterations of the design and see the evolution laid out! I currently designing a tool for testing an industrial automation component that is going to be using a small part of the uCurrent power supply - I'm aiming to have the tester be battery pack powered and the small design of the uCurrent is perfect! Tho I haven't gotten past the prototype stage yet so the bench power supply is the power source currently.

[@TheHuesSciTech]

This is about as exciting as if Valve had released Half Life 3! Great to find out details about this mysterious project!

[@wakkowarner7391]

Isn't that called Half Life Alyx?

[@ag.cousins]

I enjoy watching your channel, E squared VBlog, always refreshing to see a new video from E squared VBlog.

[@johnfrank6302]

Another great video Dave. More... more.. more. More of everything about them please.

[@balas3037]

Great video that walks over many many details of making a finished product,vs a bare PCB lying around the workbench (but still getting used) . I would keep this around as a case study of what not to do ,though. This could be the prototype and lessons learned for a competitive V2. Indeed some of the custom components could be a product in themselves .

[@mynameisben123]

I’m sure I’m just echoing what literally everyone is saying, but please sell these! I’m sure there are partners out there who will take on the heavy lifting of supporting a product!

[@dh2032]

and leep the isolation the way it is, even just fuse are still cheaper than replacement laptop? 🙂

[@kalimist4217]

One more amazing and awfully pathway to being upperlevel designer with scientific eyevision and thinking. Thanks again n again for that informations and designs which one is cannot be bought or have from anywhere-anyway.. Im in already fall in love of your science and thinking style of designing ~ engineering. Theres no words to say anything.. Just in glad to thank you. Thanks 🙌🙌🙌

[@inductivethinking]

CH224 is a simple usb PD controller, used in various Chinese products.

[@janeklof2769]

I would gladly pay 150 US-dollars for a well functional microSupply Power Supply - the supply would be real handy ! Thousand thanks for your many interesting and educating videos. Greetings from Stockholm ( Sweden ) and Jan Eklöf

[@JoelQO]

Hi Dave! Can you show some costs calculation about the product? This would help to get an idea about the budget to get a product working!

[@wonderfalls2]

Very cool. I'd love to know about the process of designing a custom case and having it manufactured. Looks like this one was injection molded.

[@Ray-ej3jb]

WOW! An actual electronics video from EEVBLOG!

[@Mainstream818]

I really like the design of this project and its something ive been wanted to desogn for years. Linear tech/analog devices has a really nice ldo with built in cv/cc capabilty up to 2-3A that ive been wanting to design around possibly battery powered for isolation and better noise. If you came.out with thid product i will most likely buy it just to support you and your channel. Already own your 121gw meter :)

[@ivolol]

Anyone can get a cheap switcher PSU. A low-noise front-end differentiates the product highly. Completely isolated would be a extremely nice to have feature, knowing there's no way to short stuff, but I'm sure it has a huge BOM cost with it vs not. It being able to be controlled (and isolated) over USB would also be a killer feature... A laptop telling it waveforms to produce, recording power graphs, etc. Mayyybe it could all be done over WiFi now, not sure. Allowing for slightly bigger or fatter case, I'm not sure if that'd help making BOM easier. The LCD is still extremely nice. You can buy 100 chinese products and wish they had a better UX like this with 99 of 'em. I wonder if simplifying the design to be slightly more 'modular' might be doable... with the aim of allowing the community to adapt the core functionality into real hardware products themselves. An analogy would be, the Marlin 3D printer software project provides itself as the 'core component', which anyone can implement into hardware to complete a 3D printer.

[@HL65536]

If I built one one of these I would: - use a raspberry pi rp2040 - have the software open source and collaboratively developed by your audience. - use an off the shelf lcd with a resolution in the range of ~320x320 - use the biggest inductor/transformer that fits in the case - make it have overkill power carrying components so no cooling is needed / short term overload mode possible - make it able to use either USB power or a 18650 holder that can be clipped on the back (there you have your "isolation") - make it have a micro SD card slot for datalogging / custom programmed sequences (e.g. CCCV charging but with slow start for deeply discharged cells, or for simulating a battery that loses voltage while discharged, ...) - generally make it use software wherever possible so it can be functionally enhanced later on by the community.

[@m4dizzle]

What a Bobby Dazzler, would love to see one in my tech bag some day!

[@frankbose544]

Yes Dave all the micro supply content please

[@erichpwagner]

Why did you go for two series pass devices, I am surprised you didn't roll current pass and voltage pass into one transistor?

[@fabianmuhlberger6153]

A small bench top battery powered PSU would actually be very useful. 2 adjustable channels with up to 20V + some USB ports or dedicated 3.3V and 5V output. I mostly work with MCU's and I think that would be useful for many others too. Cool to see an update on the project. The Power Supply videos were one of the first I watched. As luck would happen, I just printed a small enclosure for a riden PSU and just put usbc trigger board in it to get 20 volts out of it.

[@fedimakni1200]

A comparison video between prototype schematic and production schematic will be a very good video i think

[@XtianApi]

I would absolutely buy that LCD

[@jtb2586]

Ah yes, David2, the hot guy bringing us joy. Miss him.🥲

[@rowanlidbury]

Where did he go.?

[@markwebcraft]

I really enjoyed the micro supply series. Some of your best content by far... I really wish you would at least finish the project out, screw selling it, that's a whole different thing really. I assume little David properly wrote the software for it at a level well beyond your capabilities leaving you no way to really progress it anymore. A real shame but I'd certainly be interested in watching a simpler version be developed. Your deep dive development videos were the best.

[@EEVblog]

This is not finished enough? It's a great looking working product. You are right that it would be hard for me to get up to speed with the software. I've done a video on that, and it's rather complicated.

[@youtubeviewer7077]

love project videos the most

[@brianmathis5423]

Not sure if you've seen it, but Miniware offers a 5 amp, 30 volt output USB-C power supply (MDP-P906) and a barrel jack that let's you do up to 10 amp output

[@tHaH4x0r]

Death due to scope creep! It's a shame because it was a really neat idea, though it produced a ton of good videos, I suppose that is output as well. Seeing the internals of the prototype, I can imagine that it must have been very costly if produced. Honestly I would have ditched the custom display, keypad, fancy case (instead of the simple one) and transformer very quickly. To ditch the isolation in general, I am not so sure about it, not just the versatility but also isolation from conducted emissions on the other side. I would definitely add two output channels though! Just having two output channels instead of one opens up so many more possibilities (especially for analog circuits with dual rails). Seeing the output circuitry you could probably simplify it significantly, at least to a single output device instead of two.

[@pabloibaceta5932]

Finally!! You release some. The idea keeps interesting me.. but, i will remove the isolation and make it fully switching.. nice prototype btw❤

[@flymypg]

While I like the final keypad layout, I'm no longer a fan of the plastic membrane over dome keys (too many membrane failures, especially after sun/UV exposure), preferring touch PCBs whenever they can work, and carbon contact or mechanical keys when they don't. That said, I'd eagerly buy whatever is on the uSupply! Yes, drop the built-in isolation. I just got a terrific 74 WH (20K mAh) USB-C PD battery bank for under US$25, a small price to pay for total isolation. Should I need more, I'd use an isolated wall wart. One function I do want in the uSupply is a dedicated battery substitute/simulator, with an optional add-on kit of mock batteries with flex cable connections. Start with the most common (AA, AAA, CR2032, 18650) and include (or allow us to program) the capacity and discharge curves. I'm remodeling my home and will be including a massive IoT home automation upgrade, and need to design/adapt many of my own nodes, where I need to do some real-world testing to make decisions for power (wired, battery, solar) and communications (wired/wireless). Bonus points if the battery simulator can also account for physical charging, such as for an attached solar cell. Yes, the battery simulator may prove to be a major upgrade, but I believe it could help secure a solid market for the uSupply in professional labs, beyond the hobby market.

[@flymypg]

Hmmm. I'd probably want TWO uSupply units: One to simulate the battery, and another to simulate a solar cell. Edit: And I could probably control battery/solar simulation in real-time over SCPI, though I'd prefer a standalone solution that wouldn't tie up a computer. Edit2: Heck, I'd probably have the computer there anyway, for data logging. So maybe give the uSupply a large data logger as well?

[@sparqqling]

I would be interested, but see a limit at 150 USD. The market for low noise is limited and for isolation even less. The case looks good, same for the pad and the display. Can you run a poll? with cost an features to find a sweet spot?

[@Nik930714]

If you remove the isolation, increase the output power a bit, and the price is reasonable, I'd consider it. It looks so usable.

[@mbainrot]

I have a pet project too which has tech debt thanks to the troubles. Uses an STM32 G4 series MCU which is pretty good, nice and fast with flash for days but the stm32duino library is missing features that would provide some nice QOL improvements (no midi over usb for G4, no arduino like bootloader, have to flash it using SWD or boot the chip in DFU mode) and now things are mostly back to normal I don't have as much free time. Doesn't help as time has progressed I have learned so much which makes a lot of the original design not so great (figured out a cheaper/better way of doing dual voltage, thou untested. Have a hardware based idea on how to make flashing it over USB less painful, etc) . But atleast it has a sexy front panel with ENIG which did came out a treat with USB connector fitting like a glove. And atleast with a bit more programming work I can at least get it to a "working enough" stage for it to be more useful (in it's current state it's sort-of useful). Was interesting to see how the pros do it, I do like the idea of using word docs to capture snippets of information, much better than a cluster-f of notes in physical notebooks and dozens of datasheet printouts that invariably get lost.

[@McTroyd]

22:00 As someone who sometimes finds himself on the wrong side of a decimal point, the up-down arrow would be preferred. (Granted, it's probably less an issue for a supply that tops out at 12v and 1 amp.) To make the data entry faster, perhaps double-tap the up or down button for the respective adjoining digit, then adjust accordingly. 37:30 Edit: Honestly, I don't blame you for opting not to produce this. There's a lot of cheapies these days that do a shockingly good job (thinking specifically of Rui Deng, which I think you previously reviewed). I really like the integration you have here, but without some kind of real differentiation from the cheapies, I doubt it would get any traction. 40:00 Edit 2: Would like to hear a bit more about that (planar?) isolation transformer, and maybe tips to design for isolation in general. You've touched on isolation lots, but I don't remember that you've done a deep dive on that.

[@ferrumignis]

It would make it larger but I'd really like to see a rotary encoder to manually adjust voltages and currents on the fly. As you say, it's just too dangerous to do that with direct numeric entry. Even up down arrows can be dangerous if you have the option to choose with significant digit they adjust and you inadvertently move it. Not that I'd know anything about accidently jamming 13.3v into a 3.3v circuit...

[@McTroyd]

@@ferrumignis Experience is the best teacher. 😅

[@Karthor.]

I like the keypad design more

[@johnsonlam]

Wow! Too bad not a product for sale, may fill the Hi-End accuracy level market. Fun to know more.

[@thanosprionas6919]

We would like to see all your prototypes till the final product!

[@fredfred2363]

I would so buy this if it were for sale... 👍🏻🇬🇧

[@Arek_R.]

If I would be asked to simplify the design so it's cheaper and less of a headache I would probably make it take 20V PD triggered with one of the chinese 10c trigger ICs, if you plug non PD power you still get 5V (enters lower power mode). Then just use some generic step-up/step-down converter design. Also I forgot what was the reason behind custom LCD, but I think it's better to just go with some off the shelf screen, smaller as well probably, it might have been for lower power consumption but I don't think it's that much of a problem considering you can get 10Ah powerbanks under $20. I've achieved something alike with $20 hobby RC li-po charger that has adjustable DC output function and one of those chinese USB-C PD triggers (set to 20V), obviously the output is noisy, interface is ass, and low accuracy voltage/current regulation.

[@kennethng8346]

Isolated power supply isn't. used much, but sometimes its real handy to prevent possible grounding issues.

[@stevenbliss989]

The LCD has amazing contrast! :)

[@necessaryevil8615]

I enjoy your projects, even the ones you don't finish! Are you going to start designing another project soon?

[@tlhIngan]

I would suggest that isolation is required because you don't know what the user might use for input power. They may be in a pinch and unplug their laptop and use its AC adapter, for example. Or they may plug it into their laptop. Or they may have a number of USB-C cables on their desk and then need to probe around with their oscilloscope. It's too easy to run into a situation where you might not realize you're not isolated and in the blurriness of working at 3AM, the darkness of some awkward location, well, you can create some nifty accidents. Heck, I have to warn people who are probing around my board because my setup isn't isolated from mains unlike other test rigs.

[@dogastus]

Did you ever give any consideration to EMC compatibility and factor in possible costs of getting it tested for FCCand CE etc certification? There might be the need for screening. Would be great for you to do a video on some pre-compliance testing.

[@hubertrybak]

go for it!

[@bennguyen1313]

I'd like to see the uCurrent make a comeback!

[@JAKOB1977]

On what ground were you expecting to land bomwise, as your obviously aint to just winging it, with a retail sale product in the tube. - it doesn't look like your got any plans to bring it to market, so could be interesting to hear about the inner margins you were hurdling.. fx expected BOMcost and the price you were targeting. but there are few of these tiny PSUs.. got a couple.. EEVblog for fx "DP100".. a 100W PD3 jobby (30v5A) that you can get for like 40 to 45US incl delivery and 25% EUVAT... obviously another fish, but both tiny TypeC PD PSU intended for mobility... miniware also got some older module based variants

[@Germanwtb]

I'd say for 150$ (before tariffs) I'd buy this, but that'd be the limit.

[@SaltCollecta]

@@Matthias_Fischer I think it is you who needs help.

[@arcrad]

Oh no, microservices have made their way to the PCB layout world.

[@jensschroder8214]

Yes, the display on a PCB and an 8-bit micro display driver so that could be controlled via SPI or I2C. Would certainly be salable as a side project. Hobbyists could take it and build it into a power supply themselves.

[@roboman2444]

It would be really cool to see that be made IP67 or whatever. Probably just re-shaping the heatsink a little and including a rubber oring/gasket so it seals to the back case would work. For Banana jack, you can make a cutout in the PCB as wide as the outside diameter of the banana jack, and edge plate the copper there, then solder the jack directly to it. I've seen many battery chargers that do this technique. Probably not the best for avoiding cracking. A toggleable backlight (or frontlight?) for the LCD would be really nice.

[@frosty129]

Ip67 is impossible because heat sinks need airflow. What do you wanna use a power supply under water for, Aquaman?

[@jaro6985]

@@frosty129 no, you've never used a plugpack, they have heatsinks and are sealed.

[@frosty129]

This is why you’re an engineer and not an entrepreneur Dave. You have no idea how much money that little supply can make you and how much demand there is for a low cost, ultra low noise, precise, isolated, stable, fast, and battery powered supply. This solves so many people’s pain points, and can make 10s of millions of dollars. I say its a greater value add than any entertainment on KZbin. But it’s hard to execute.

[@EEVblog]

10's of millions of dollars? LOL I've been selling kits and products into this niche market for 30+ years, I think I know a thing or two. Never speak for other people, you'll come-a-gutsa more often than not.

[@MD4564]

LCD Screen looks nice and clear. Could be cool idea iwth modern components version.

[@heyarno]

That thing would be nice for diagnosing problems with nightvision devices on the go.

[@MeiklesAndDimes]

I would pay $200-250 USD for it if it was isolated. Perhaps you could sell a cheaper model without isolation

[@markburton3306]

I wanted to make something like this after I finish my electronic load project. I use a raspberry pi pico and have implemented scpi (including wifi support). I’m quite a fan of making your own tools

[@Willy_Tepes]

I want to make an environmental sensor and was wondering if there are any biodegradable PCB's, solder mask ect because I will not be able to retrieve them. For example something made out of corn starch/gelatin and natural fibers. Preferably the only remains should be bare copper traces and the chips, passives, ect. Or would dead bug technique be my only option?

[@TilmanBaumann]

I'm glad you can afford to let go of this. I remember it was a great ride to see it getting designed. I think anyone looking for a portable powersupply should just get the MDP from miniware

[@jaro6985]

The UI on the miniware is garbage though.

[@cmuller1441]

LCD videos 5 years ago... At that progress rate it will be available on AliExpress earlier than on Dave's shop...

[@buidelrat132]

Let's start designing a new one!

[@steveb1600]

It can be the best pocket-sized power supply in the market. I hope you can sell as many as 1,000,000 units.

[@YashKudale]

What was your plan for the vents to make it dust proof? and what were the gotchas on those? I don't think you have talked about it previously.

[@petersage5157]

It actually looks more like those pocket oscilloscopes that Dave loved to bash. Custom case, but it looks so very much like a repurposed iPod. Sexy? Nah. Cute though. I also think those pocket DSOs are cute. I wanna get one of the newer ones with the single knob interface like Clive recently featured in one of his videos.

[@James-wb1iq]

Can the uSupply compete with a single channel of something like a Keysight E36300? If so, I'd happily pay $500 per channel for something that I can stack on my desk as 3x channels for bench use, then pick up and take outside for field testing. Especially if there was space for a big prismatic lithium cell built right into the housing. I tried the Miniware MDP-P905 for this purpose ($235 AUD) and unfortunately ran into QA issues. Also no built-in battery, and no isolation. The Keysight beast is $900 AUD per channel, takes up half a desk, and is too heavy to take outside. Add high speed metering and data logging (like the Joulescope - 2 MS with glitch free range switching), and I'd happily pay $1500 AUD per channel, if it also had the battery (actually, that's roughly what a Joulescope costs, so maybe a bit more). Right now I know of no good solution for powering and monitoring battery operated devices with uA sleep currents and ~0.5 A transmit currents, in the field. To the point that we're making a cheap commercial solution (like a Kill-a-watt for IoT devices). But if you had something higher spec for sale even at Keysight prices, we'd buy a handful in a heartbeat for prototype testing.

[@frosty129]

It definitely won’t compete with Keysight because they use FPGA to control the pass transistor. And they use toroidal transformers to reduce noise. That comes at the cost of space and weight. The switch mode preregulator has to be extremely low noise and low emi to be able to compete, perhaps with slow switching edges, ferrite beads, and multi stage LC filters before the linear section. But then it starts getting inefficient, large and heavy. It’s like you can’t have your cake and eat it too.

[@antonrnnedal7797]

LCD for sale, yes thank you.

[@Kijo21]

What about the AD5560 it’s basically an SMU in one chip, would be nice in such an amazing looking handheld equipment especially with USB-C power delivery and communication for IV-Curve Tracer. What do you think?

[@jaro6985]

interesting, its quite old 2012, there is an LT part as well, LT1970 if you've not seen it already (DC2591A). AD5560 is about $38/ea.

[@Kijo21]

⁠@@jaro6985 sorry for the late response. Yeah I‘ve seen the LT1970 and there is already a finished SMU based around this Chip (uSMU from joeltroughton, it’s quit a good design). But if you want to extend your Power output capacity you would be better of with the AD5560. Yes it’s a bit more price but for example you don’t need a separate DAC‘s for CC/CV because they are already built in. Overall the AD5560 is a hell of a complex Chip (just look at the datasheet, it blows my mind every time) but I think the level of integration it provides is more important than cost. Feel free to contact me.

[@mhdalessandro]

MPS has some nice PD ICs but programming one would be a real pain

[@ElektronikLabor]

Dave, why do you still use Altium 17 as an former Altium employee?

[@EEVblog]

I unknowingly fired up an old version for this. I do have 23 installed.

[@ElektronikLabor]

@@EEVblog I must admit I also have still AD17 installed, just in case

[@henryD9363]

Three significant cost items are Deluxe LCD display, Deluxe Keyboard, and Isolation. I would rather keep the isolation and cheap up on the keyboard and display.

[@jaro6985]

The custom LCD and keypad are cheap in volume, $1 each or less. You'd be paying the same or more for a generic color LCD or OLED.

[@frogz]

that is pretty awesome but i would like a barrel jack as well for backup of the usbc, usb isnt always the strongest physically and i have SO many random laptop supplies

[@TilmanBaumann]

I think I would still love to have a large Powerbank with controllable DC output these days. But the really cool options are too expensive.

[@TradieTrev]

Great break down of the design. What is young David doing these days? If I had my time again I would of just studied harder at school and be an electronics tech than an electrician.

[@EEVblog2]

I believe he's still doing contract design work.

[@mrvisual2482]

@@EEVblog2 You should get in touch, have a talk and publish it on the second channel. Always nice to know what happened over the years.

[@seppeon]

@@EEVblog2 Indeed I am :)

[@ecospider5]

What a tease

[@franz6135]

Great video that I watched with big interest! Curious why the CC and CV loop control separate mosfets (Q1 and Q2) while I find more lab power supply designs that only use one power mosfet (or power transistor) that is controlled by the CC and CV loop simultaneously. Furthermore I was surprised to see the CC loop in front of the CV loop. Off-the-cuff I would have put the CV loop in front of the CC loop. Or does it even matter? I have to admit I'm a rookie but questions like this bug me and help me to learn. Will try to simulate it.

[@Paxmax]

Definitely drop the internal isolated conversion, so many cheap power options available to tinkerers. The whole base idea with ubiquity of USB PD is to give user those options to begin with. The "analog mucking about" and low noise design is quickly becoming a lost art I believe... I love the mucking about, that's how I learn... while enjoying it too! As for price point, would be good if this could be made somewhat within touching vicinity of $100-150. Pre-conversion/tracking voltage just makes me warm fuzzy inside with throwbacks to (almost unrelated) Bob Carvers audio amplifiers. Electronics is practically analog anyway you cut it. (Ok, if you zoom down to each individual electrons "personal" state - granted those are stepped... as far as we think we know) One thing I think about for my personal use, backlight? (Even a crappy one is better than none) Is possible with just a few SMD side-shine LEDs?

[@cannesahs]

isolation would be differiating feature. what are your output voltage, current, power range?

[@ElectraFlarefire]

The low noise would be the real selling point. All the cheaper ones seem to use switching. Good enough for simple stuff, but I'd imagine frustrating otherwise. I agree that the isolation is less important these days, though I wonder if it's easier to do combined isolated/tracking first stage(with just an isolated i2c for the USB-PD chip and the digital pot on the USB side to remove the second micro) nowadays with that low noise final stage. Just armchair engineering. It's just a shame to see a product not really finished, but so long as there was fun had making it, that is 90% of the goals. :)

[@EEVblog]

The project is actually technically finished. It looks and works just fine. I just chose not to produce it.

[@ElectraFlarefire]

@@EEVblog Fair.

[@pete3897]

What was customized about the case? Was there a video on that? I enjoyed the LCD one and the keycap one :)

[@EEVblog]

It's a completely custom 3D design. I don't think I did a video on that.

[@pete3897]

@@EEVblog A missed opportunity! One for the ideas bin :) I can't even tell how it's made due to my ignorance (injection moulded?) - but I'd love to find out.

[@yoksel99]

I wish something like this was built in into a multimeter. Suggest this to Brymen?

[@lazerusmfh]

I have one similar that has usb pd input and dc I put but has a limited output w usb pd. Super freaking handy

[@tlhIngan]

Who wants to bet the Altium modular design was meant to sell Altium licenses? Because with all that fancy linking going on, you're going to want to license Altium so people cna view the schematic. Sure, you can print it to PDF, but with all the modular bits, it's going to be really annoying to navigate - best you pay up to save your sanity. They later fixed this with Altium365 which at least allowed us who don't need full Altium the ability to navigate the schematic with a half-decent web viewer and not just PDFs .

[@Nisstyre56]

the isolation is important for anything with audio I think

[@jayfowler4747]

I was hoping this would become something i could get in the future, so how about just selling the remaining stock as a kit of the custom and programmed parts and we find the rest... that way you can get your money back on the stuff you bought and the viewers can get a cool psu for field work....

[@EEVblog]

It's not that easy. And there is no "stock".

[@jayfowler4747]

@@EEVblog that's a shame there must be hundreds of hours of work that went in to those prototypes... but like you said there's stuff on the net that will do the job for a fraction of the cost, I suppose the takeaway for this is tech moves too fast for small scale development... if you don't have a team of devs you can't keep up...

[@electrodacus]

David2, Joules is just Ws so why not use that ? :)

[@EEVblog2]

Fanboys be fanboys.

[@john_hind]

How about just making a linear regulator and using the PD voltage negotiation as the pre-regulator?

[@jaro6985]

Yeah thats what I was doing originally. But with USB PD you only have 5, 9, 15 and 20V so worst case you'd have to drop 6V which may be a lot. Quick charge you can actually do 0.2V steps, if I remember. So QC is more useful here, But not universal.

[@trickyd499]

What is Dave 2 doing?

[@han5vk]

What exactly was the point of making everything custom besides making it super expensive?

[@XtianApi]

Always more