500V to 12V 3A power supply (with schematic)
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- Опубліковано 14 жов 2020
- I've always thought that the only place you'd get a three phase PSU was from an industrial supplier, but it turns out eBay has everything.
This really nice unit is sold as being for a 380V AC supply (two phases of a Chinese 220V supply), but on the manufacturers site it suggests it has a range of up to 528V AC and 746V DC. I'm not sure I'd push it that far though.
The module is clearly made to industrial standards. Really good separation and what appears to be a proper isolated transformer design, with well placed components and a bias towards reliability instead of cost. One particularly nice feature is the output overvoltage safety net of a second simple voltage clamping zener in the feedback circuit, so if the voltage reference fails the output voltage will only go up by a few volts.
This has to be one of the best looking power supplies that I have seen that isn't a prominent brand like Mean Well. It's perhaps notable that this company is called Munpower and has a logo that hints at the Mean Well logo.
Some equipment has two or three phase supplies, but no neutral. That's where this module could be used to provide power to control circuitry. It might also have uses in DC electrical traction equipment. Some extra VDRs/MOVs to clip voltage transients would be useful if doing that.
If you enjoy these videos you can help support the channel with a dollar for coffee, cookies and random gadgets for disassembly at:-
www.bigclive.com/coffee.htm
This also keeps the channel independent of UA-cam's advertising algorithms allowing it to be a bit more dangerous and naughty. - Наука та технологія
This video is very useful not only for high voltage power supply, but for understanding any switching design. Thank you for sharing it!
Sure is. it's a clever made product, analysed by a clever man.
Yes, I wish my university courses were this clear, and helpful. I swear I learned more about switch mode design from this channel than from getting an engineering degree.
Danger Danger, high voltage!
How is peak of a sine wave RMS x root of 3?
It should be root of 2.
And no load rectified voltage of a sine wave is always the peak voltage of the AC sine.
BigClive talks about the so-called "line voltage" which is the AC (RMS) voltage measured between two lines of a 3-phase AC system. Because of elementary geometric reasons, this voltage is equal to the phase voltage (measured between a line and the common / neutral conductor) multiplied by square root of 3 (approx. 1.732). Thus, a domestic 240 V single-phase line originates as one of the lines of a 415 V 3-phase system.
Nice break out Clive. I'm a retired 17 year US Navy electronics tech from the end of the tube / bulb era and I have to commend you on your circuit explanation skills. The course of my career would have been much different had you been instructing my cohort.
I LIKE tubes/valves.... 👍
Grade school would have been so much better if they had used examples like this in math class.
I only took 1 semester of electrical engineering classes, and got stuck on nortonizing and thevenizing circuits... I think if I had UA-cam and Clive back then, I probably would have gone further into electronics engineering, and not as much into technical support, oh well... Both are necessary and decent paths. Thanks for all your hard work Clive, hopefully some folks are learning new stuff, and will be able to apply it in future careers.
Grad school would've been so much better if they'd used examples like this.
@@ericmallory3050 From the engineering side, I salute you in technical support.
@DIY Projects Let me guess, you had to swim to school, 30 miles up hill each way dodging icebergs and the hungry polar bears on them?
Commonly used on lathes and mills for running the control electronics
They don't have a neutral?
@@mnbvcx Some do, many don't due to using delta wiring for the motor for higher torque.
Makes a lot of sense.
@@LeePorte
You are absolutely right. Many old pieces of 3 phase equipment run off a 3 pin plug only + earth, instead of a 5 pin plug (3 phases + neutral + earth).
Some of these machines now need sensors, counters, and other monitoring equipment to be added to them that require low voltage (12V or 24V DC) and be powered from the machine's own mains supply, hence they use these kind of converters.
It is simpler and cheaper to use this kind of supply than run a new separate neutral wire to the machine that may be many meters away from the nearest available junction point.
@@mnbvcxNo neutral. There are 3 live wires that basically alternate between the 3 being live and then neutral throughout the sine wave cycles.
It definitely helped to go over the simpler power supply schematic first.
That is a LOT of very high-quality design (and componentry) for just over ten Pounds (UK)!The isolation is superb, and the Kapton tape wrap around the pulse transformer is the icing on the cake. Excellent products like this tend to refute the popular (although mis-informed) "Chinese Crap" meme.
Also the strange belief that they lack the ability to do their own research and design.
When Clive talked about those big huge transformers, I couldn't help but look over at my collection of Stuff from the old Bethlehem Steel Plant in Bethlehem PA. I have no clue what it was used for but it weighs 35 pounds. I was told that at their prime Bethlehem Steel bought only the best equipment for their operations. RIP Bethlehem Steel.
Everything was overengineered in the steelworks. It had to be robust and any down time was expensive and could cause major issues with a slab of molten steel halfway through a machine.
"Lady Beth" was a movie a guy made about the workers of the Bethlehem Steel plant in Los Angeles. I remember when I was a pre-teen, watching the steel pulled out of the oven, yellow hot, and seeing it go through the steel mill. Just awesome! That was a good living for the workers, but all the steel comes from foreign countries now. 😥😥
There was a hill in the Hazelwood section of Pittsburgh that looked down on the Jones and Laughlin coke works. When they dumped the red hot slag it was like a window into hell. Red dust would stream from the defroster vents in your car. But boy did those workers rake in the cash.
I have four 55V 22A industrial transformers. Those things are big and heavy.
@@rpbajb Those workers faced gruesome fates just around the retirement age. Just like my grandfather, who worked 30+ years at a papermill. Everyone in his neighbourhood got cancer, but some guys managed to die to other health problems.
Now all the steel comes from other dontgiveadamn -countries...
Oh, Clive, you are worth every penny! That initial explanation of a simple, 'idealised' SMPS was the first time I've really understood the whole system from start to finish. More of that sort of basic explanation would be most appreciated. Great work!
Excellent reverse engineering explanation - many thanks - I now understand considerably more about the mysteries of SM PSU design and operation.
The classic flyback switch mode supplies are so standard that they seem familiar after a while.
Agreed. The more I listen to BC talk through these circuits the more I get familiar with them. Like learning a foreign language. Regular immersion helps.
The quality is SUPERB! Now that's a new Clive word!
That's the way that all SMPSes should be made. With Safety in mind.
There’s also 48 volt DC switching mode power supplies that are designed like that to run on three phase power but they are usually massive as they are normally designed to output hundreds of amps of current in order to power server equipment! :)
Or telco "-48vdc" battery banks. I have a stack of PoE power supplies from Cisco Cat 4500s -- over 100A @ 48vdc.
1:10 well, by now ebay sellers know that if they get an order from the isle of man, they will soon get follow-up business from all over the place.
...........seriously, i wouldnt have half of the chinese crap i do now if it wasnt for this channel, i dunno why some companies refuse to send to him!
@@frogz maybe they're hesitant to have the actual quality of their products revealed on UA-cam.
I just made a similar comment, saw yours so deleted it.
@@frogz Same, the amount of stuff I do not need that I have bought because of Clive is ridiculous. I wish he would put links 'below' to make it easier for me to buy said crap..
@@tncorgi92 I think it’s more so because he is on the Isle of Man haha
That's beautiful. So nice to see an actually well-made power supply for a change.
I once built a 3-phase rectifier for the armature of a 20HP(!!) DC motor -- for a previous satellite-ground-terminal restoration project. The old control system used a 3-phase motor driving a DC generator. It was a thing of retro beauty. Lots of big relays and contactors and big power resistors and thyratrons. The control rack weighed (with the Motor-Gen sets) about 2 tonnes!
Your explanation of how a SMPS works is great! Well explained and easy to follow. I've been learning electronics (slowly) since I was a child and never clearly understood how they worked, therefore, how to properly troubleshoot them, but now I do. Thanks!
Nice anti-tracking, multiple resistors to spread dissipation, beefy over-rated components, intelligent design - I'm truly impressed!
About the only thing I would do differently would have been to spread those resistors as far as practical - some of them didn’t need to be crammed so close to each other. Otherwise it looks like a solid design, although definitely only targeting clean environments. This one would fail spectacularly in a lot of heavy industrial environments. Probably OK if the industry one has in mind is something like pharmaceutical manufacturing in a clean hall.
This was a fantastic episode. I really feel like I am getting the idea. Thank you.
Extremely clear description of the entire circuit. A joy to follow along! Only suggestion would be to add transformer winding dot notation on the schematic for added clarity.
Well explained and always clear photos and circuits. Thanks Clive.
No clue what he's ever really talking about, but still love watching. I find it quite soothing for some weird reason.
Just raising the frequency from 60Hz to 400Hz allows you to reduce the amount of iron in a motor or transformer by 80%.
but watchout for your decoupling capacitors!
That was usually done onboard aircraft: 3 phases 115V / 400Hz power lines (together with 14/28VDC)
Thanks for those videos Clive, they make it rather easy to actually understand what is happening inside devices you might have around you (well, a 500V PSU is probably not one of them, but anyway :P).
Excellent video! Helped a lot in understanding the main difference between a low voltage power supply and a high voltage power supply. Thanks for the detailed information. :)
I like the way you do the things. Print the Ebay screenshot instead of paste film. Make yours films so smooth👍
I wish I was smart enough to understand even a word, but I still enjoy your videos! 😊
Clive, you seem excited about this one. Enjoy your videos very much. Cheers from Perth Western Australia. 👍🇦🇺
It was genuinely very interesting to explore.
I learnt a lot from that video. Thanks again.
@@bigclivedotcom And the quality surprized you I think...
Awesome Clive! Fantastic timing also... I was in dier need of some easy relaxing content to sit bk and soak in ✅👍🏻
A few months ago, I started looking at designing a power supply that can supply 20-30A at 12V or 16V when powered from 300-520V DC, the twist is that it should also be able to work at much lower voltages with reduced output current. Application is an auxiliary power supply for a solar inverter. Decided to put it off and work on other parts of the system first.
Great video as always BC. Thank you.
It's not often we see Clive extol the virtues of a far eastern product, but this one is an example that stands out from the crowd, and we can see that Clive absolutely loves it. Construction wise, it reminds me of the PSU in our ancient (late 1980s) STC/SDX PABX, though only single phase in our case, but with very similar excellent electrical separation and well thought out design - necessitated no doubt by the need for an ultra safe supply for equipment which all but directly coupled to ones lug-holes!
best one yet Clive, basics are the best :) this is what makes life real....
About the need for 400V PSUs, recently I put together a small control box for a portable paint mixing tank... We have a lot of 4pole IEC plugs at work (from the time they were switching over from the metal-case flat blade plugs) and they're all you need for a motor, but I had to do some low-voltage control (due to the contactron turning the motor of) I had to go for a 400V-24V transformer (had to be reliable in a very harsh environment) was much more feasible than changing 30 IEC sockets and like 50 plugs on other devices
wow. when winkling bits from old things i have often wondered at those triangular pads beneath the chokes. i seem to find them in old amplifiers rather often. thanks for clearing that up.
and i must say it really impresses me when a creator can be arsed to heart a comment on a video they posted years ago. it demonstrates your willingness to engage beautifully. i actually _suspected_ you may heart the comment, as you have done it a few times with my comments on ancient vids. cheers mate
This was an excellent explanation of the power supply. It was very well thought out, and easy to follow.
I like the use of the linear regulator to adjust the feedback output voltage. That is a clever use I had not seen before.
I don't like the use of parallel diodes on the output rectifier to get s higher current rating. The two diodes in a single package have good chance of matching since they are most likely on the same substrate. However it is highly unlikely that the diodes in separate packages match, especially over temperature and this could lead to current hogging.
It would be interesting to see how much emi it generates. The snubber across the output rectifier at least shows they were thinking about it.
Thank you!
The parts used (SBR20150CT) are rated at 10A average rectified current per leg (x 4 legs). It looks like they probably didn't need the 2nd package since it only has a 3A rating.
Hm, maybe this is something the Chinese industry actually makes to be used by themselves and not just shipped abroad with zero regard to anything that happens after that.
Agreed. Probably not the usual export eBay factory seconds.
Still likely cloned from a western company's work.
The power supply was purchased from a company in the UK. It could be that the UK company had them built to the UK or EU specifications. The Chinese aren't known for making things safer and more expensive; on the contrary!!
@@acmefixer1 That's not really true. The Chinese can make products to any quality level you're willing to pay for. No one that uses the flea market known as ePay will pay for quality so you find dodgy garbage there (and Amazon.)
Don't blame the Chinese. They make some of the best equipment in the world.
Instead blame the shonky importers who buy at the the lowest possible price.
This made me very aware I had dun a Dunning-Kruger, having watched a great many of these sorts of videos from the back of the class. Earlier I would have been hard pressed to tell the difference between this and a bottom of the barrel power supply!
That thing meets or beats Sola and Phoenix Contact supplies. I would install that without hesitation.
e: About half of the three-phase machines we built tapped their control power directly from the mains, and we only ever used single-phase like these for that application. A couple of air handlers in the plant actually used a full three-phase 480 VAC:24 VDC supply, which always vaguely worried me, but clearly it's fine.
Brilliant explanation...I learned a lot of random bits and bobs....I am hoping to find some analysis off Grid connect inverter and IGBT welder products on your channel
Great vid Clive...Very well explained..
23:11... "times two" writes three
i have just noticed that as well
LMAO "MOSFET-y like things" That made me laugh so hard it hurts. I love Clive's videos.
amazing content as always big guy
I very much appreciate you reverse engineering the circuit and describing its operation.
Thanks so much for sharing. 😉👌🏼
That looks like a good design.
Running across two phases at 208v is common in the US for some high rise places where they don't take the neutral up. Some principle as this. Hence why a lot of appliances are rated 200 to 250v as the US uses -120v and +120v to give a 240v potential, and then using the different phases to create the slighly lower 208v voltage. If all that makes sense.
Its Very common in industrial equipment to not have a neutral. Its common to only feed with 3ph+PE. Hence there is quite a few variants available. Both from 3ph->1ph+"N" and 3ph->DC. The former is usually always present to create an isolated system supply.
I would expect 3-phase to low-voltage DC supplies to be readily available because the standard residential supply in Germany is, according to what I've learned from the German maker channels I'm subscribed to, 3-phase. It looks like just about all electric appliance motors in Germany are 3-phase. It's also really nice for power tools, and means the difference between consumer-grade and professional-grade mills, lathes, table saws, and similar tools is probably much smaller.
it's common but not standard as far as I know. And even when you have three phase available is not like there is outlet in every room.
Most homes also have neutral and safety earth, so 220V/50Hz is readily available for small appliances, and a proper 5-wire cable makes it available inside machines too. Big 3-phase motors are commonly switched to a Y configuration to lower inrush current during start, the center of the Y connects the switched ends of all 3 coils to neutral. For full power, the knob is turned to Δ, connecting the switched ends to the previous phase, leaving the neutral to only power the controller and auxiliary equipment.
Certifying this stuff is hard: Every single part will be either shorted or cut (put into one of its failure modes) before the circuit is tested, and the circuit must not catch fire, explode or have overvoltage on secondary. There are many permutations even for a small number of parts, so it gets very pricy, too. I hope that the chip has a safety feature which stops switching if the optocoupler fails.
There is no absolutely reliable switching power supply.
There is no absolutely reliable switching power supply.
@@user-pu6pr2tj3t "Absolutely reliable", no. You're certainly right about that. But I think Paul's point was more about how to test that if/when it fails, it does so SAFELY so as not to catch fire or kill someone.
@@mikefochtman7164 But perhaps 泽泽 was making the point that you cannot MITIGATE for ALL scenarios and even safety features can fail. The 'best-laid plans of mice and men' and all that?
@@wthornton7346 Yes, that's always possible I suppose. After all, to test for safety, we have to know exactly what sort of failures to anticipate. Components may open or short, but if they blow apart and short out surrounding solder pads.... well that's a lot harder to predict the effects.
Nice one Clive, that PSU has certainly had some thought put into it, what with the creepage slots and the resisters in series, I am impressed for a chinese built PSU.
it's nice to see creepage slots and copper plane keepouts... but the only way they have a chance of calling this "safe" is to have no altitude derating and claim Installation Category II (residential threat level). Category III (most common for industrial) starts at 6mm for >300V, but most designs I've been a part of use 9-12mm.
@@dl5244 Yep. It’s basically everything done right but way too compact for hard core heavy industrial use. In many an industry just the dust would kill any and all isolation in this cute little thing. I’ve seen similar supply running in the control box of an NC tool grinder. The conductive steel dust made the 24VDC control circuits ride on top of 200V 60Hz, apparently resistively divided by conductive dust from the 400VAC input. We replaced with same rated supply but literally 2x the dimensions. No more problem - the dust particles are too small to bridge all the cutouts now :)
I think the snubber network on the primary side is mainly used when the power supply has low load. And the shunt over the output diodes are for absorbing that rapid pulse mentioned before the diodes have time to turn on.
Nice vid mate
An issue that often arises in valve amps comes to mind here. When putting the two 68uF caps in series, the exposed end of one of the cans will have 250 - 300Vdc on it!
And so what ?
Switching supply saves shipping weight, and cost. Reminded me in 1980 the eng VP confused a sales rep when he told him we needed the brute force transformer.
Because we charged $5000 for the receiver and customers thought it weighted enough to be worth the price (had only 2 Z80s, 8k ram & 2 2708s).
Thanks Clive!
Nice lesson my friend
I really find your explanation of ccts, although l can read ccts and understand the basics I've not got depth of knowledge that you have so l find your diagnosis rare down very enlightening! I've mainly worked on transmitter repairs Lf to Hf 20w to 20kw some Marconi Hf auto tune,intresting thing was auto tuning always got lower I P, s inter modulation products! Than l could get on manuel tuning! On H f tx! Also uhf txs 500ml w to25w, l once saw the result of standding wave on mistuned 10kw hf tx that set fire to AE patch panel,that happen whilst l was in middle of manuel tuning, and main supply failed,and as usual despite d o e resting standby generator every month, as usual it failed to get up to speed to produce 240v so l had to go outside to generator adjust speed regulator! so by time l got back in tx hall, only2mins tx had come back on line,in mistuned state and standing wave just happened to meet @AE patch panel plug setting on fire! There was a b.e.r.s site on island, British eastern relay svs l got to pay visit to they had mega w tx,they show me result of mistuned tx,feeder to AE size of large drain pipe 2ft dia,it had melted/blown hole in aluminium feeder! This bit you'll well understand, they had2 very large paxman generators, can't remember power!must have been meg watts for such high power HF tx. Sombody had really bad day when running up standby gen and getting the phase out of alinment with on line gen,as in for change over,there was friging humus bang, alternator stalled engine,which promtelly blew engine up,very big deisel engine, that then despatched it's self thro roof of building, engine size of around 2double decker buses, really bad day for BBC facility shut down for repair for some time,theyve moved now from island to mainland Arabia. Short distance across sea.
I think your fingers weren't listening properly at 23:05 when you *said* "×2 gives 3,000" and *wrote* "×3" 😼
When recording videos I'm thinking ahead of what I'm going to say, so at the time I tried to write 2 my brain was already at 3-thousand.
Yeah our Hass cnc has them I believe. They take in 480 three phase and it's about 500v in the morning due to nothing on that side of town being on because it's the industrial side of town.
@@bigclivedotcom I often do that when I'm making notes at work. Last letter of some words gets replaced by the first of the next word!!
It is nice to see that EBAY is selling some "deathtaps" (Play on words.)
I usually go through automation direct for my 240 and 480VAC to DC power supplies at the best price with certifications. But a quality non certified unit is always handy in a pinch.
Don't forget the dots on the transformer. A flyback is wound with oppositely wound windings unlike any other type of transformer. (Technically is isn't even a transformer, but a (not-very-well-)coupled inductor)
that circuit / board design is at a high standard for such a low cost , not often found these days - good one
Hmm, I've been long keeping my eye out for a 208volt 2-phase power supply like this...
I've never even thought that eBay might have something like this. I'll have to take a look
Keep in mind that many of the power supplies are suited to 220V use as standard.
Really impressive, when you consider the very genesis of the creative innovation along with the brainchild of the mere thought process into a schematic, and onto the planning the data of what's needed in size shape, input and output and then create materials needed, and making , or finding mass amounts,..anyway, I digress, .. it really is interesting.
Good videos Clive.👍
Excellently explained. I'd like to see a DC power supply that takes it's supply from all three phases and how that works.
It would have six diodes. two per phase, but would also need extra filtering too.
@@bigclivedotcom Could you explain why that is? In my head I imagined it needing less but the ripple would be at a higher frequency.
really good video
ST it's the mark of the beast.
I recently repaired and parcially reverce ing. the control unit of my condensing boiler by viessmann.
It's full of ST ic and for some reasons finding the datasheets for this brand was a royal pain in the... you know, the easter bunny think.
They also make almost identical two other configuration: 5V 6A, and 4V 1.5A. Just some different configuration of some resistors, capacitors and transformer probably, and maybe some diodes. Same PCB exactly. It actually can work down to 100V AC, and 141-746V DC.
Good to see my favorite YT channel hasn't been deleted without notice.
There's still time yet.
Follow your fave 'Tubers on LBRY, OdySee, BitChute, DLive and Twitch.
Well done.
Another possible application for these SMPS's is electric cars. The main battery voltage is in the 500v range. Yet they also use 12v electrical accessories like lights and other electronics, probably because these are off the shelf for building of cars and at least the Tesla still has a standard 12v battery in addition to the high voltage propulsion battery.
A friend of mine tried turning down the supply to a computer power supply, it worked with a small load down to below 20v, all the output voltages were correct, so i think your psu should work too, just at a lower max current maybe.
It will work when you start at a higher voltage and then turn it down. Won’t start from 20VAC even with no load though. Should try to start between 60-80VAC usually.
Surprisingly well made for $5.
Ebay seller: why is everyone buying this? We need to raise the price.
That's why I usually provide eBay search links starting at lowest price first. That way the price raise causes their listing to slip down the queue.
Or, "Hey boss, Big Clive just placed an order."
"Quick, double the price."
@@bigclivedotcom
can have a look at this Big Clive if you have some spare time, i think you will be interested your more knowledgeable.
Just LED light ??
ua-cam.com/video/gyAi8HXgFR8/v-deo.html
Cheers the Monk
@@monkfu7101 That video is a complete load of rubbish. 450V capacitor? That guy has no idea what he's talking about, he's the fool himself. Trying to convince people that a street light can scan into thier houses? Whatever next. Reporting your comment as SPAM hopefully it will be deleted ASAP.
@@AAAyyyGGG really ? Big transformers for LED lights would be perfect for 20 GHz to 300 GHz range !! 60 GHz range is interesting it affects oxygen don't think you would want one out side your window !! If sound can bring down stone walls am sure a few body cells would be much easier ?
I'm always intrigued with 3 phase circuitry, thanks! Btw, Did you leave the foam up? You sound muffled...
That's a different room
Seems a lot of gubbins and effort, nicely done, I tend to just take off 240v from one of the phases for my control, contactors, relays etc. for invertors for motor drive.....
The snubber across the primary winding is of the voltage-clamp type, which should not be used with a flyback topology. At least only with great care and consideration.
I miss videos on more complex circuits like this.
A very long time ago I was contracting at a company that made the drop towers for quartz fiber optic cable. There was a new induction oven for larger billets which was water cooled on the outside and took 100A per phase. It needed such a high water pressure it was unreal but we didn't have the pump yet and one of the bosses wanted it tested so a water tank was put on the roof of the gantry tower as that was six stories. The hoses were fitted and a wide drain pipe fitted and the tank was filled. The water flow valve was opened up and the electricity turned on. Then all hall broke loose. The high pressure supply came off spraying water like a fire hose, and the supervisor dived in (almost literally with that much water) trying to push it back on to the fitting shouting "Oh no, oh no, oh no in a Brummie accent which somehow made it funnier. There was an almost perfect 180 degree fan of water with about a 3 meter radius. The owner of the company came down to see what the havoc was and just pissed himself laughing. The induction oven got so hot it turned to slag and scorched the concrete. That was after the power was off. There was a huge amount of latent heat (I'm going from memory of about 25 years ago). The boss checked everyone was uninjured and then just pissed himself laughing all over again. The supervisor was sent home as he was a bit shaken and told to come in the next morning. The boss the next morning took one look at him and started laughing all over again. Nobody got any kind of formal reprimand and there was an open meeting on the shop floor held by the top boss focusing on how we could stop this happening again. The only thing that happened was the supervisor got the wooden spoon at the Christmas party. It was one of those companies that had awards for the trainee who made the biggest advance in ability etc. Pity there are so few companies about like this any more. Anyway that's my story about the only time I ever worked with 3 phase.
Look! A Chinese product with character. Now that's refreshing!
Pretty impressive little power supply considering its origin :)
If by its origin you mean China, I'm not surprised that they know what they're doing. Chinese companies seem to know how to operate on different levels, whatever makes commercial sense to them. If the customer wants to pay next to nothing for cheap shit, they deliver exactly that. If the customer is willing to pay a fair price (but still affordable) and wants properly engineered products then they can do that, too.
As are the industry standard Mean Well supplies. China makes everything from excellent power supplies to really crap ones.
This isn't a full 3-phase unit though, and there's one advantage of having a full 3-phase because then you can use a 3-phase rectifier and get a smoother current.
But common mode suppression is more complicated on 3-phase.
100% agree. 3phase input adds redundancy/reliability, but if you need to pass emissions/immunity standards your filters get BIG, losses increase, and $$$ goes way up
MOTHER OF ALL FULLEST BRIDGE RECTIFIER!
Its only a 36W unit, just not worth the extra complexity. For higher powers you'd want full 3-phases to keep the phases balanced of course.
I see big capacitors.
This video is going to be interesting.
Hopefully with lots of explosions and circuitry catching fire.
Well, I think you are on the wrong channel for this kind of stuff. Search for ElectroBoom :-)
@@Poebbelmann He's the great teacher everyone wished they had for Science at school. Thanks, but I already found Mehdi 5 years ago! Clive sometimes does have his moments of destruction though.
I'd love to see this kind of reverse engineering done for a contemporary desktop PC power-supply.
Clive can sleeve my output windings...
Can he also reverse engineer your circuitry?
and he'll say, "ooooh, that's odd." on a regular basis
Ehhhh!
Big picture lol good explanation & video clive😁
And I do use quite a lot of big pictures.
@@bigclivedotcom you sure do 😆🤪
@@bigclivedotcom Big Clive, Big Pictures. That’s just Common Sense (tm).
Maybe we should all pitch in to get BigClive to register a trademark with Her Majesty’s relevant Office. Why not, lol.
Interested to hear your thoughts on cheaper lab type power supplies.
GREAT Lesson Clive. Now I think I under stand SMPS. Could U1 be PWM Controller like On Semi NCP1251?
My coincidence I've had videos of rotary converters used in the New York subway recommended to me recently. It's not clear in the videos if these 115 year old machines are still in use, but the ones they have are fully operational. One thing that came up in discussion was how 3-phase rectification gives less ripple, albeit at a higher frequency. IME w/ linear amplifiers having liner power supplies, single phase ripple can be tamed easily enough, and any remaining ripple is barely audible at 50/60 Hz, where 150/180 would be more obvious. I don't know if switchers need to be careful about ripple, as it's sliced and diced in the next step.
Nice reverse engineering & explanation vid!
How long would you estimate this design would last compared to a design that uses a large transformer instead of a SMPS?
You paid 8.85£ for the PS, how much would a comparable PS cost that uses a large transformer?
Thanks for sharing!
Great video. Thanks bigclive for sharing. What is the purpose of the link just south of C5 @24:30 that seems to goes nowhere?
That is not a "link". Those are two of secondary wires from the flyback transformer.
Wow Cool Pro-Unit...
"And it's going to positive... Pretty sure it's going to positive", he says, while having his pen pointing at "V-" marking on the PCB.
Yes I saw that too, byt maybe he's actually correct. Is there is a throughhole inductor taking it to the positive?
perfect...videos
Hi Clive, i have a amp that works but the LCD is dead, i read about dry solder and cold solder joints and looking at the board, this seems the only feasible possibility, i don't know if you have discussed this in your videos or demonstrated fixing this type of issue, but maybe it is an idea for a video as it is pretty relevant, i would like to repair it myself, but i want to be prepared before i attempt such a task, long time fan of your work and i highly respect your knowledge.
Some newer viewers of Clive might think on first glance that Clive has a rather low production value for his videos, but the truth is he spends all of his production value on ink cartridges so he can print out full color photos of PCBs on massive canvases!
Bulk ink system. Lasts over a year per refill.
I was watching one of your videos from 2-3 years ago where you said you were thinking about making a video about electron theory and you haven't yet. You should make that video.
It always stalls at magnetism. I didn't realise that "How does a magnet work?" could be such a complicated question.
@@bigclivedotcom It's farked, I know from my attempts at working it out in my "Quantifications of Energy", I've made some progress around the concept by finding SI-based equations that -don't- kill the mind when trying to bridge the gap between "designing the transformer" and "designing the circuit"...
Let's just say that what's getting me, is how cross-sectional area of the transformer relates to power capabilities - I've worked out many of the other concepts in magnetism though...
It's a strange nut to crack, but not as hard as the involvement of radiation as an energy - but we use it's base unit of 'energy-level' everyday, the Electron *Volt* ...
And since I had built some radiation detectors [Ion Chambers], I wanted to be able to 'accurately' measure radioactivity - and for that a decisive quantification of the stuff was required, which on and off has taken me a few years to get through, but I think I finished it two weeks ago, still need to hit my conjecture with rounds of testing to be sure my theory is actually useful or not!
It's probably a good idea to break it down into units, make it episodic starting with what you know well, and you'll probably crack that magnetism stuff in the meantime :]
How does the optoisolator feedback work? Is it pulsed on for 'overvoltage' so the control chip can reduce it's PWM duty cycle? They've got a 14V reference. Do they use the potential divider network to get a 12V reference and then compare the output voltage to that?
The TL431 turns when it sees its input exceed its internal 2.5v reference. The 14 volt zener usually doesn't do anything but is present just in case the 431 fails open.
The optoisolator feedback starts pulsing as the voltage goes above the set point (here 12V). Since the output waveform is triangular-ish, this sort of feedback works well - it doesn’t need to be “analog”, since the waveform is stereotypical, so instead it’s PWM of sorts, and the controller can use that fact if it wishes.
Great video Clive. I am not seeing a link; is there a link to these?
They do make 3p power supplies to 24vdc din mounted. However I just use 1 leg of a 3p power supply to a 1p power supply.
If that reference to ground through the screw hole was connected would it stop the ‘fuzz’ feeling you get on the 0v output or would that remain?
Directly connecting the output negative to ground would eliminate the fuzz. But that cap could help reduce it.
I'm 100% convinced BigClive and Jim Browning must be from the same town. They sound , soo much alike