In my opinion, videos like this are some of the most powerful for all the DIY hobbyists. Like me, most of us have no formal training in electronics, but this video gives us very relevant reasons to try and wrap our heads around complex and somewhat arbitrary concepts. Having a broad understanding of what might cause noise or ripple on a power supply / buck-boost converter is in every DIY hobbyist's best interest. Please make more content like this!
@@greatscottlab Didnt check it, but probably an edit of the previous video would be quite useful too. Not everyone in the future is going to watch both
Ich habe das gleiche Teil in Verwendung und mich extrem über das Ergebnis gewundert. Ich habe das Netzteil analysiert, da wir Industrie Netzteile suchen, die einen kleinen Formfaktor haben, programmierbar sind und ca 500W bei ca 50V können. Das Netzteil kam in die engere Auswahl. Das Ding ist wirklich gut, da können andere echt einpacken. Das einzige, es hat kein DIN Rail.
That was both an honourable and brave move, much appreciated! I was thinking to get one of those PSUs, but decided not to when you mentioned the output noise.
I was hoping you would do a video like this. Taking cheap aliexpress or ebay electronics that are ALMOST good enough and then cheaply modifying them to fix or improve their performance. You should make more of these.
It REALLY grinds my gears when a product gets ruined by bean counter measures. "Oh we saved a few cents on this device!" "But its complete crap now?" "Who cares? We get money!"
Man, it's crazy how much you can accomplish pretty cost-effectively if you understand electronics. It's something I'm trying to learn, but it's not easy for me to understand electricity and how everything relates to each other. Thanks for the videos, they're helpful in slowly getting more understanding of things.
This is true for anything, from auto mechanics, plumbers, carpenters, yada yada. Outside of basic volts, amps, Ohm's Law, etc, electronics are going to require a fairly deep amount of study/work before you're going to be able to figure much out not too mention fixing a borked design. I've decided to spend the extra 25% or so for something thats generally been shown to be good vs trying to eke out the cheapest component/parts. If I'm trying to cobble something together, the last thing I want to do is be wondering if some pre-made component is even doing what I bought it too do.
Don't worry about some of these things. The higher the frequency the more electronics starts to look like black magic. That's even to people who have degrees in it or similar fields.
@@arthurmoore9488lmao, for real. I work in automation and the amount of troubleshooting I have to do with highly sensitive equipment near robots, or other high frequency loads is aggravating. Sometimes the shield isn’t grounded well enough, sometimes the shield is too small, sometimes it’s grounded too well and creates a ground loop that effectively acts like an antenna that picks up RF noise. Part of me loves it, part of me hates it. Haha
Man, I've been an electronics hobbyist since the late 1980's, and I'm always surprised at how little I know. Just keep tinkering. And when you get a chance to use an oscilloscope, seize the opportunity
You typically do not put large MLCCs on the output of a power supply because when they fail, they fail with a burn so you use small ceramic caps paired with low ESR caps
I am curious about your answer, so I get deep into it, there is an article from TDK, called"Guide to replacing an electrolytic capacitor with a MLCC", it recommends to replace with MLCC due to their low ESR, long life and small package, but one should be careful about their capacitance will change with temparature and voltage applied to them, also some ICs are intended for electrolytic capacitor, so it might cause some unwanted feedback with MLCC. Also there is a youtube video discuss about fail of MLCC called "EEVblog #1037 - Solving Ceramic Capacitor Cracking ". Large value MLCC can be cracked physically easily, and it might get shorted when that happened, I guess that's why modern hign-end PC motherboard still using the method you said, rather than pure MLCC method.
@@tingoyeh4903 I had soldered a MLCC underneath an electrolytic in an ATX PSU which had undesirable high ripple output. Eventually while I was at the computer, there was a pop sound. The MLCC probably became hot and failed short which burnt down the electrolytic releasing gas.
1. To save money 2. The only people that are going to care/notice are people like us. 3. The people like us know how to fix the problem. My guess. Keep up the good work bud.
Care? No. The only people who are likely to KNOW why their thing fails, and also choose not to buy from the same supplier, are us. This is simply capitalism at work. It is more profitable to sell more of a thing that is cheap-but-bad than it is to sell something slightly more expensive-but-better, even accounting for the returns. And since you change the company name/registration for every product, you don't care about repeat business. It's a cynical take, but this really is built-in to the business plan nowadays.
Cost is its own spec. If you want higher performance for your use case, be prepared to pay more. If the performance of the cheap part is acceptable, you can pay less for something that satisfies you. ETA: And no, it's not "capitalism," it's scarcity. When resources are limited, it doesn't make sense to spend them on performance you don't need. You need Star Trek replicators to escape this, not a replacement political economy.
@@jdotoz Managing scarcity is the PRIMARY job of any economic system. It is WHY we have economies. (Ultra)Capitalism is a BAD economic system because the way we are using it now is tuned almost exclusively to "make money number go up" instead of ACTUALLY managing resource scarcity and distribution. So yes, the problem IS capitalism, because the SYSTEM punishes you for making things well if it costs less to make them worse. None of the economic systems we use now can handle short-term products that break prematurely. They can't self-regulate when there is too much turbulence.
Ah the classic current loop antenna, that’s why you were picking up all that noise. Any loop will act as a current antenna. And any length of copper, will act as a monopole if adjacent to a ground plane or bipole if connect to a center point. Good luck.
That's why you should always use your devices inside a hermetically sealed bunker surrounded by 10cm copper plate, 1.2m lead plate, and 3m of grounded-steel-reinforced concrete. Everything should be made with pre-nuclear-test materials to reduce self-radiation. The bunker should also be carved into the base of a mountain, or built into the sea-bed with at least 200m of water overhead if you want to block those pesky cosmic rays. You still need to account for all the Neutrinos that can still easily get through, but luckily those usually don't interact with your electronics if they can get through all your other defenses.
Honestly, if it's a $0.50 component, that's why they didn't include it. They're shaving pennies off of the price of these things and producing them in huge numbers with tiny profits to stay in business. A device that is 90% effective is good enough from that viewpoint.
The tip at 9:56 about measuring temperatures to determine if reactive components have appropriate parameters was really helpful. That point alone made this video valuable.
I too have burned a few MT3608's...they do seem to be unreliable. At 11:09 you say add a 2.2 microfarad ceramic capacitor but the links in the description are for different ones so I am unsure which is correct.
9:47 your forgetting that at the volume they're producing these at the increase in BOM cost is even less at under 0.19 EUR / piece on orders of 1000. Probably also a slight price decrease at 10k and 25k as well. Therefore at volume this is likely no more than 0.15 - 0.17 EUR in parts, and the lower quality parts they're using probably cost 0.08-0.11 EUR, so we're talking about them pinching literal pennies to not have a better product.
@@greatscottlab yeah unfortunately so. Though I know BigClive in his teardowns of electronics like this from china on aliexpress or otherwise mentions that they tend to have resistors and capacitors overdriven for their intended purpose for whatever reason.
@@pappaflammyboi5799 Dont forget about what the product itself cost spending 0,08€ on a 1€ board is a huge increase in price. For most stuff you dont need that clean power, so it is good practice to not build them in.
That ringing on the switch node of the inductor can be suppressed with a snubber network and is easily missed, this I know from first hand experience! Also sometimes adding a beefy cap can make things worse, Mach1Designs did an EMC video on the caps and is very helpful in locating noise and killing it.
I never knew to check temperature to check out components in a design to see if good or bad. Only to look for a broken component(s) when fixing. Maybe they stole an incomplete design from someone else? Lazy? Possibly just stupid? 🎉 I am still learning. I bought an old radio/cassette player and a radio clock alarm that both work to study on. I will use your temperature trick to maybe improve them. Thank you for giving us a great channel with interesting projects.
Your devices were probably made in the 90s or earlier, so I wouldn't count on them having the same trashy engineering as modern devices from AliExpress. Good luck with your endeavors though.
High frequencies tend to cause caps & mosfets to heat, for different reasons, but the solution is pretty much the same: lower the resistance. Low ESR caps have much lower resistance, and 'bigger' mosfets have lower RDSon, which is essentially the resistance that causes most of their heat. It's always funny to see a low-tech troubleshooting technique on high frequency IC's. Elegance in it's simplicity.
Seconded. The diode temp probe is a precise method of spotting an overheating device. Slower but many times better than a finger touch. I'm impressed by your thoroughness.
I used a pile of old 1ohm 50W resistors to make a grid on an aluminum plate. You can jumper quite a few different loads and can dissipate lots of heat.
For the UPS I simply replaced the 2x220 uF capacitors with a 22 uF tantalum low ESR and a 470uF electrolytic as recommended by the chip data sheet. That cleaned up the noise. I used 1x probe and attenuation.
That's a wonderful example of what a difference good capacitors make. I'm amazed that the short probe ground wire makes such a difference. Have you tried measuring at 20MHz with the ground wire?
My guess for why they didn't go the slightly more expensive route is sourcing. This is all guesswork mind you, but if they produce in house, it's only costing them pennies per. One thing I've noticed about Ali is many vendors offer the same product at different prices, so that would explain why they want to keep the price low...sort of a lowest bidder thing. Lastly, the 50 cent price you quoted is the retail price, so it would slightly increase their profit margin as they'd be paying wholesale. 😊
For a lot of stuff on Ali/AE, there are one or two companies making gajillions of these as OEM-Contract. Some resellers want different color silkscreen, some spec differrent values for some components to get a lower BOM, etc. Chinese business looks at cost cutting as the primary goal bar none. Doesn't matter if it impact the specs of these design, unless/until they are called on it and IF they can be forced to pay some sort of remuneration. It is always worth it to keep value engineering a design/product which leads to higher profit, until/unless they are forced to remunerate. There is not a lot of care/f*cks given for 'Reputation' as you see from Japanese, EU, Noram companies. Talk to some engineers from China, and they will all admit it. They don't like seeing their work cut down to out of spec anymore than anyone else.
One major contributing factor to noisy outputs on many cheap/Asian Aliexpress-alike regulators is poor layout. Take e.g. 8:50 - they use polygon pours to reduce impedance (good) and provide more thermal mass/lower thermal resistance (good), but all the components are still awfully, widely spaced, leaving still considerable inductances, which is especially bad on the switch node, as it has high current ripple. As V = L * di/dt and your L (trace inductance) is high, your di is high and your dt is small, this creates ripple noise. And as layout is something inherent to your PCB (it IS your PCB basically), you cannot easily change the noise created from bad layout. Even the best components can deliver embarrasing performance if you do not do the layout right. Remeber, electronics is not so much about charges moving, but about controlling and containing your fields. But there are far more talented people out there, which can explain that in much better detail and accuracy.
One of the 1st things our teachers told us at LTI is the difference between an expensive VCR and a cheap VCR is a 5 cent component. Like they will use a 1/4 watt resistor to dissipate a 1/4 watt of power rather than using a half watt resistor. Everything today is built down to a price, its the race to the bottom which got us lots of cheap junk.
I think it is because of cost. Like the MT3608 boost converter, here in Indonesia it listed around 5200 to 6500 IDR (0.32€ to 0.37€). By adding the better ceramic capacitor priced 0.5€, imagine how much it affecting the price. For me, the initial design is more than enough, reminding the price is dirt cheap. Unless for specific reason I need to modify, like the one you tell about creating negative voltage, I'm set my expectation according to the price I paid 😅
Well, a 20% 22uF MLCC costs 500 IDR (0.03 EUR) on Indonesia's Tokoijo, and the manufacturer would have been able to source it for cheaper. So it's not an excuse.
The side ground pin in the oscilloscope probe is a very nice solution. A spring loaded measuring pin would still improve measuring a shivering hand (a so called test pin "needle" for production beds).
8:14 i love how you put the images of components next to the schematic components -- for those of us trying to take self learning electronics seriously, it massively helps our brains put to mind the components as if they were legos (but the various values of each 'lego' is like the lego color). Next after looking at this for a while as a reference during test building on our own, the schematic components begin to fit like a catalog in our brains before we even realize it. I hope i not sounding too nuts but this really works for my brain very exceleratredly, ty for this idea and i hope you and others do that much more often -- even if just once before you do the red pen work on the circuit would be a big help ^_^ p.s. i have loved your work for last many years, ty for keep doing your channel ! 😀
Oftentimes, these boards are based around one key component, i.e. the regulator IC. If you were to reverse engineer the board and compare the resulting schematics to the IC's reference design, you'll find probably little to no differences. And very often, the designers doesn't really pay much attention to the textual parts of the datasheet that explains the values and different usage cases, or just use one calculation for all their product runs (i.e. the same capacitors for fixed 3.3V, 5V, 12V and variable variants of the board). Also, the reason they won't add it is cost and availability. They already most likely have tens of thousands of cheap small mlcc caps around, adding one to the output won't change the BOM cost by much, but also doesn't have to affect the output in the desirable way, or even hurt it. Thank you for showing us this
I always see keysight sponsoring many electronics chanbels but it would be nice if you could make a video how it looks inside one of their mesuring devices (maybe you could get a broken one or something from keysight from their rma or something like that )
I have a bunch of those same buck converters that I'd like to fix, but the links provided are for a 22uf and 1uf capacitor, but the video mentions a 2.2 uf on the output? So which one is correct to fix the final small buck converter? The 22uf link or the 2.2uf mentioned in the video? Thanks in advance for your time to answer.
A lot of noise I deal with in electronics is 60 hertz noise because all the power supplies use a iron core transformer instead of a ferrite core transformer and the reason why that makes a difference is because all iron core transformers run at 50 or 60 hertz well ferrite transformers run at higher frequencies. And 60 hertz noise is very noticeable if you're using inductors and highly sensitive electronics
When switching to the MLCCs, why the smaller capacitance? Is it a limitation of what's available or do you not need as much capacitance when the other properties are better?
As a guess it was the largest commonly available capacity for the needed voltage rating and component size he decided on. He might have took the switching frequency into consideration but can largely be ignored if the original design worked at all.
What's the names of the type's of test probe's used first at @2:33, the one in the background it pushes open and hooks against the wire lead and then closes to make a sure it cant short on anything.. And then again a different style tester probe with the positive in the center and then a ground lead coming down from the side, @4:34 ? Thanks!
Thank you very much for the video. How could you make the UPS not charge the battery at such a high voltage? For example, charge it only at 4.1v to increase battery life. Thank you so much
This was a very interesting and also useful video! I found especially interesting the bandwidth limit on the oscilloscope. Can you make a video to explain why it's limited during official measurements, the implications about having strong peaks beyond that bandwidth limit and how to absorb them if so desired (I know this part: ferrites rings/beads around the wire). Thanks!
I also want to know. I bought 2 of each, 5V, 9V and 12V, for alarm/cameras and just in case. One seller has it for 4$ each and there was also 1$ from 5$ coupon for playing (and losing) in Go go match game, but this promo ended. So they were really cheap.
Well mt3608 module comes with 10uF MLCC on the output already, just wondering how does 2.2uf additional cap could make such difference in noise reduction ?
Another awesome video! In the video you said 2.2 uF ceramic capacitor for the mini boost converter. But the website link goes to a 22 uF ceramic capacitor. Is it meant to be 22 uF or 2.2 uF?
50 cents can be a lot on a large scale production. Aluminum caps are easily replaceble and do less damage the board than the ceramic ones when they fail.
I ordered the parts from Mouser, so now the two UPS devices going to get the upgrade. I even have 5 of those boost converters to that I will do the same with. Thanks for this great fix video. Great stuff as always. Now I just need to find a cheap-ass oscilloscope, so I can test other electronics I have lying around.
About the UPS: Is it possible, that there are no MLCCs at the output? The elkos have a too high esr to filter the output voltage. It could be worth a try, if there is a suitable footprint close
Oh interesting - I have some AliExpress modules with caps that get hot. USB-C power modules I use in power banks. Is it a pretty safe upgrade to just replace the electrolytic output filter caps with multilayer ceramic caps with the same uF value? Is there value or risk in going with more uF?
Two 100K ohm resistors, a 2.5 V reference diode, and an OpAmp and you can also get a very stable 5V with current up to the opamp’s output current rating. Also, thank you for admitting a mistake, many wouldn’t be willing to say that, very cool!
I used to do component level troubleshooting for a manufacturer of cable tv monitoring equipment. Here is the answer to the question of why don't they use better components, at least for them. Their engineering team used 1% tolerance parts when designing and prototyping. They would hand off the list of components needed never specifying what tolerance (if any) of parts should be used. Naturally, procurement bought the cheapest stuff they could find. I practically begged management to let me talk to the engineering team. They finally brought one guy down. I sat him down, showed him the log I had been keeping, and the exact parts that needed tighter tolerances. In this case it turned out to be the inductors in a frequency generation circuit. The board pass/fail rate jumped to over 70% (it was in the upper 50's). My big reward for figuring that out was I got to be the end of the line guy. If I couldn't fix it, it went into the trash. I didn't last long there
Well... I've got some of those mini boost converters and i already knew that something wasn't right. Only a small SMD capacitor on the output. On my projects when i used those boost converter modules, i always added some extra capacitors on the output (Both electrolythic and MLCC). DC-DC converters are INCREDIBLY useful in basically everything. I wanted to ask if you can make a video where you analize a 'special kind' of DC-DC converter, the one used in ALL car audio amplifiers: A single rail to double supply rail DC-DC converter. I could not find any appropriate schematics anywhere. This DC-DC converter is really useful but i just cant find a way to make a proper DIY version. A lot of people is probably searching a way to make this DIY... I think that a video about this topic will explode on views! (And help a lot of people too). A DIY version is really versatile, because you can have full control over both the output voltage and the power that the circuit can handle. It would also be a nice learning experience. With this circuit, a battery can run ANY audio amplifier!!
At high frequencies such as in these switching power supplies, standard electrolytic capacitors have too high of an “equivalent series resistance” (ESR) and should not be used in this type of application; that ESR leads to excessive heating. Low ESR electrolytic capacitors are designed for these applications. The small ceramic capacitor heating up is a bit surprising since they are intended for use with high frequencies; perhaps that was a cheaply made part, and that is why it showed a higher than expected temperature.
Hi, what would happen if you use a higher voltage input for a boost convertor above it's input limit. Would it malfunction, or would it keep the output voltage to the set output?
one question, that capacitor fix for mini boost converter. what is the limit voltage for that fix, i see in the description that is 10v capacitor so what about 12-15-18v dc?
BTW, good on ya, for showing the error in probing technique! It is *such* a common issue that it's kind of like "is the power plugged in" question for oscilloscope AEs !
I have a similar boost converter from Ali that already has a capacitor installed at the specified location. They're advertised as being able to boost up to 28V but none of them went above 19.xV, sadge. I wanted to use them to deliver a higher voltage to 24V fans T_T. Any quick fixes that come to mind? They are of the MT3608 type with USB-C in, rated for 2V-24V in and 5V-28V out.
Sure this will get lost but what tip do you have in that iron handle….I have same handle and right now I only have tiny tips awesome for smd work but it’s just not enough thermal mass for bigger stuff… what you had looked perfect
They might just do that now. We are constantly reinventing the wheel and working towards making something as efficient as possible. Thanks for the videos you put out man it has significantly added to my progression of circuit design.
I have some experience in real market production and can take an educated guess to why such things occur: Case A - The Manufacturer is not aware of the issue due to one of the following: 1 - prototype worked well but somewhere in production someone deviated from the design due to the lack of some component 2 - a partner provided a batch of bad components 3 - lazy (minimum testing) or non-existent QC 4 - following (copying) a design blindly not knowing how slight changes might affect the result 5 - Damaged components due to bad quality / bad storage Case B - The Manufacturer is aware of the issue: 1 - Greed 2 - discovering the issue in late stages of production (happens a lot) so they lower the price to not throw away the stock and to avoid fixing the issue which is sometimes very hard to near impossible / costly 3 - they just don't care 4 - indented for uses with high tolerance to error
06:22 Additional to further reduce output noise, add capacitor parallel to R1. Start with say 0.1uF. This will inject output noise in feedback path & can help reduce output noise further.
that makes for a PID controller, you are injecting a part of the noise in the PWM regulation which could create instability... If the dynamic regulation is OK, you should not touch it but improve output filtering IMHO
Can you please test de peak current on the input of those booster boards? They seem to put high amps for like some milliseconds at start. I fried some 7805 by feeding the input those boosters, they were tuned to output about 8V for a small
This is not a complaint about this fantastic video on what can be done to achieve better results from inexpensive switching power supplies, just a reminder that buying what appears to be inexpensive component parts can be very expensive when you come to pay for them to be shipped to you! 50c for a component is a great fix, but let us remember that no component supplier is going to ship you a 50c component for free, most suppliers have a minimum order price + shipping, which can make small projects VERY expensive to build. This is even more frustrating here in the UK where buying let us say GBP 10.00 in components can result in you paying GBP 10.00 in shipping, so when you want a GBP 0.50 regulator you have to either buy 100 off of them or pay the minimum order charge plus their shipping. Sorry for the whine, but a lot of UA-cam videos on building small electronic items forget these hidden costs.
I did the same sinc my Bugconverte Cap was acting as SC because of ESR i realised ceremic might be good option since it's easy to find from old motherboard or pcb .
Replacing the output capacitor with a low ESR one reduces noise, but also the power supply ripple. Often that ripple is needed for stability of the voltage regulator. I would always recommend to stick with replacements to similar components and not deviate too much from the original implementation, unless one can measure the stability afterwards. Bad stability is often much worse than noise.
I bought the UPS circuit in 5V and 12V versions, but I've received 9V instead of 12V, so from this video I've easily recognised the resistors to swap for the voltage divider, but buying the exact components is not feasible due to the shipping costs, so I went to the harvest route. The problem is that my multimeter is not very good at measuring resistance, so I harvested some similar resistor from another circuit that had similar resistance without really knowing the exact number. Well the good part is that I managed to obtain 7V, 10V, 13,5V and 20V and left it at 13,5 that is the most similar (also should allow more power and staying close to 12V during high loads). It will be useful to know the exact resistance, maybe you could pick it up again and make a couple of final upgrades: a potentiometer to regulate the voltage and an interruptor to disconnect the batteries when not needed. Maybe design a cool box 🙃. Having a clean output is not always critical, especially if I know such regulation is done at the receiving end.
Just received mine, a 5V and a 12V. Will be using 1 for a solar project. Just be careful with the voltages! Capacitors seem rated at 16V max and I would stay at least 10 to 20% below that. Checked my 12V version and that smd resistor R7 has a marking 9092 which is 90.9 KOhm or 90.900 Ohm. Also the board has been changed as his has R7 and R7* . The R7* has turned into R12. I would always opt for a clean output. Spikes can produce noise on radios if you use longer wires and in some cases cause strange effects. I always also place a 100nF cap on the input and output.
In my opinion, videos like this are some of the most powerful for all the DIY hobbyists. Like me, most of us have no formal training in electronics, but this video gives us very relevant reasons to try and wrap our heads around complex and somewhat arbitrary concepts. Having a broad understanding of what might cause noise or ripple on a power supply / buck-boost converter is in every DIY hobbyist's best interest. Please make more content like this!
Mad props for clearing up the mistake you made in the other video.
I am always open to admitting mistakes :-)
@@greatscottlab Didnt check it, but probably an edit of the previous video would be quite useful too. Not everyone in the future is going to watch both
Ich habe das gleiche Teil in Verwendung und mich extrem über das Ergebnis gewundert. Ich habe das Netzteil analysiert, da wir Industrie Netzteile suchen, die einen kleinen Formfaktor haben, programmierbar sind und ca 500W bei ca 50V können. Das Netzteil kam in die engere Auswahl. Das Ding ist wirklich gut, da können andere echt einpacken. Das einzige, es hat kein DIN Rail.
That was both an honourable and brave move, much appreciated! I was thinking to get one of those PSUs, but decided not to when you mentioned the output noise.
I've got this in my cart at Ali so now i can buy without doubts
I was hoping you would do a video like this. Taking cheap aliexpress or ebay electronics that are ALMOST good enough and then cheaply modifying them to fix or improve their performance. You should make more of these.
YOH - Chinese labor is getting expensive, between their demographic loss and "OUR" re-shoring the supply chain - enjoy while u got it. GOT DAT ??
It REALLY grinds my gears when a product gets ruined by bean counter measures. "Oh we saved a few cents on this device!" "But its complete crap now?" "Who cares? We get money!"
That's typical Chinese mentality...
@@haydenc2742 Not exclusive to chinese stuff.
This is consumers mentality. People don't care. People want low prices.
"Who cares? We get money!"
Welcome to Ultra Capitalism...
@@Prophes0r Applies to communists as well. Who cares, we all get paid the same amount of money!
Man, it's crazy how much you can accomplish pretty cost-effectively if you understand electronics. It's something I'm trying to learn, but it's not easy for me to understand electricity and how everything relates to each other. Thanks for the videos, they're helpful in slowly getting more understanding of things.
This is true for anything, from auto mechanics, plumbers, carpenters, yada yada. Outside of basic volts, amps, Ohm's Law, etc, electronics are going to require a fairly deep amount of study/work before you're going to be able to figure much out not too mention fixing a borked design. I've decided to spend the extra 25% or so for something thats generally been shown to be good vs trying to eke out the cheapest component/parts. If I'm trying to cobble something together, the last thing I want to do is be wondering if some pre-made component is even doing what I bought it too do.
Don't worry about some of these things. The higher the frequency the more electronics starts to look like black magic. That's even to people who have degrees in it or similar fields.
@@arthurmoore9488lmao, for real. I work in automation and the amount of troubleshooting I have to do with highly sensitive equipment near robots, or other high frequency loads is aggravating. Sometimes the shield isn’t grounded well enough, sometimes the shield is too small, sometimes it’s grounded too well and creates a ground loop that effectively acts like an antenna that picks up RF noise. Part of me loves it, part of me hates it. Haha
Man, I've been an electronics hobbyist since the late 1980's, and I'm always surprised at how little I know. Just keep tinkering. And when you get a chance to use an oscilloscope, seize the opportunity
You answered it yourself- to save 50c
You typically do not put large MLCCs on the output of a power supply because when they fail, they fail with a burn
so you use small ceramic caps paired with low ESR caps
I am curious about your answer, so I get deep into it, there is an article from TDK, called"Guide to replacing an electrolytic capacitor with a MLCC", it recommends to replace with MLCC due to their low ESR, long life and small package, but one should be careful about their capacitance will change with temparature and voltage applied to them, also some ICs are intended for electrolytic capacitor, so it might cause some unwanted feedback with MLCC.
Also there is a youtube video discuss about fail of MLCC called "EEVblog #1037 - Solving Ceramic Capacitor Cracking
". Large value MLCC can be cracked physically easily, and it might get shorted when that happened, I guess that's why modern hign-end PC motherboard still using the method you said, rather than pure MLCC method.
@@tingoyeh4903 I had soldered a MLCC underneath an electrolytic in an ATX PSU which had undesirable high ripple output. Eventually while I was at the computer, there was a pop sound. The MLCC probably became hot and failed short which burnt down the electrolytic releasing gas.
1. To save money
2. The only people that are going to care/notice are people like us.
3. The people like us know how to fix the problem.
My guess.
Keep up the good work bud.
Care? No.
The only people who are likely to KNOW why their thing fails, and also choose not to buy from the same supplier, are us.
This is simply capitalism at work. It is more profitable to sell more of a thing that is cheap-but-bad than it is to sell something slightly more expensive-but-better, even accounting for the returns. And since you change the company name/registration for every product, you don't care about repeat business.
It's a cynical take, but this really is built-in to the business plan nowadays.
@@Prophes0r no need to bring politics into this
@@cities_aviv A. It's economics.
B. Politics is in everything. It is inescapable, and the desire to escape it is part of the problem.
Cost is its own spec. If you want higher performance for your use case, be prepared to pay more. If the performance of the cheap part is acceptable, you can pay less for something that satisfies you.
ETA: And no, it's not "capitalism," it's scarcity. When resources are limited, it doesn't make sense to spend them on performance you don't need. You need Star Trek replicators to escape this, not a replacement political economy.
@@jdotoz Managing scarcity is the PRIMARY job of any economic system. It is WHY we have economies.
(Ultra)Capitalism is a BAD economic system because the way we are using it now is tuned almost exclusively to "make money number go up" instead of ACTUALLY managing resource scarcity and distribution.
So yes, the problem IS capitalism, because the SYSTEM punishes you for making things well if it costs less to make them worse.
None of the economic systems we use now can handle short-term products that break prematurely.
They can't self-regulate when there is too much turbulence.
Ah the classic current loop antenna, that’s why you were picking up all that noise. Any loop will act as a current antenna. And any length of copper, will act as a monopole if adjacent to a ground plane or bipole if connect to a center point. Good luck.
People who liked this also liked working with RF designs, where furrowing your brow rotates you on the smith chart.
Though the change he saw was huge and probably this is also telling for the EMC of those little PCBs.
That's why you should always use your devices inside a hermetically sealed bunker surrounded by 10cm copper plate, 1.2m lead plate, and 3m of grounded-steel-reinforced concrete. Everything should be made with pre-nuclear-test materials to reduce self-radiation.
The bunker should also be carved into the base of a mountain, or built into the sea-bed with at least 200m of water overhead if you want to block those pesky cosmic rays.
You still need to account for all the Neutrinos that can still easily get through, but luckily those usually don't interact with your electronics if they can get through all your other defenses.
@@Prophes0r Just build your swimming pool over your bunker.... ppfff...
@@hugegamer5988 nothing like carving your own ground leads to get the ground loop as short as possible
Honestly, if it's a $0.50 component, that's why they didn't include it. They're shaving pennies off of the price of these things and producing them in huge numbers with tiny profits to stay in business. A device that is 90% effective is good enough from that viewpoint.
The tip at 9:56 about measuring temperatures to determine if reactive components have appropriate parameters was really helpful. That point alone made this video valuable.
I too have burned a few MT3608's...they do seem to be unreliable.
At 11:09 you say add a 2.2 microfarad ceramic capacitor but the links in the description are for different ones so I am unsure which is correct.
9:47 your forgetting that at the volume they're producing these at the increase in BOM cost is even less at under 0.19 EUR / piece on orders of 1000. Probably also a slight price decrease at 10k and 25k as well. Therefore at volume this is likely no more than 0.15 - 0.17 EUR in parts, and the lower quality parts they're using probably cost 0.08-0.11 EUR, so we're talking about them pinching literal pennies to not have a better product.
True :-) That would make this story even sadder though.
@@greatscottlab yeah unfortunately so. Though I know BigClive in his teardowns of electronics like this from china on aliexpress or otherwise mentions that they tend to have resistors and capacitors overdriven for their intended purpose for whatever reason.
Like literally around 0.08€ savings. That's really sad. Someone should contact the manufacturer and ask them to reconsider their decision.
@@pappaflammyboi5799 Dont forget about what the product itself cost spending 0,08€ on a 1€ board is a huge increase in price.
For most stuff you dont need that clean power, so it is good practice to not build them in.
@@jonasstahl9826 8% is a huge increase in price? Ya, not really.
That ringing on the switch node of the inductor can be suppressed with a snubber network and is easily missed, this I know from first hand experience! Also sometimes adding a beefy cap can make things worse, Mach1Designs did an EMC video on the caps and is very helpful in locating noise and killing it.
i love people who owned up their mistakes and correct them!
I never knew to check temperature to check out components in a design to see if good or bad. Only to look for a broken component(s) when fixing. Maybe they stole an incomplete design from someone else? Lazy? Possibly just stupid? 🎉
I am still learning. I bought an old radio/cassette player and a radio clock alarm that both work to study on. I will use your temperature trick to maybe improve them. Thank you for giving us a great channel with interesting projects.
Thanks for the feedback :-) And you are welcome 🙂 I love to make this show.
Your devices were probably made in the 90s or earlier, so I wouldn't count on them having the same trashy engineering as modern devices from AliExpress. Good luck with your endeavors though.
High frequencies tend to cause caps & mosfets to heat, for different reasons, but the solution is pretty much the same: lower the resistance. Low ESR caps have much lower resistance, and 'bigger' mosfets have lower RDSon, which is essentially the resistance that causes most of their heat.
It's always funny to see a low-tech troubleshooting technique on high frequency IC's. Elegance in it's simplicity.
Seconded. The diode temp probe is a precise method of spotting an overheating device. Slower but many times better than a finger touch. I'm impressed by your thoroughness.
The electronic load might also introduce some noise, would be better to measure with a pure resistive load.
Yes this. Might be noisy as hell.
I used a pile of old 1ohm 50W resistors to make a grid on an aluminum plate. You can jumper quite a few different loads and can dissipate lots of heat.
How long until the video where he adds a component to the electronic load?
For the UPS I simply replaced the 2x220 uF capacitors with a 22 uF tantalum low ESR and a 470uF electrolytic as recommended by the chip data sheet. That cleaned up the noise. I used 1x probe and attenuation.
Can i use 2x 4700uF 16v on the output instead? I only have these at hand or the 10v 1000uF ones. 😅
That's a wonderful example of what a difference good capacitors make. I'm amazed that the short probe ground wire makes such a difference. Have you tried measuring at 20MHz with the ground wire?
It might be partially because it was so close to the unshielded switching inductor.
You are the example of someone who not only passes his exams but also completely understands what he has studied. Good work 👏👏👏
My guess for why they didn't go the slightly more expensive route is sourcing. This is all guesswork mind you, but if they produce in house, it's only costing them pennies per. One thing I've noticed about Ali is many vendors offer the same product at different prices, so that would explain why they want to keep the price low...sort of a lowest bidder thing. Lastly, the 50 cent price you quoted is the retail price, so it would slightly increase their profit margin as they'd be paying wholesale. 😊
For a lot of stuff on Ali/AE, there are one or two companies making gajillions of these as OEM-Contract. Some resellers want different color silkscreen, some spec differrent values for some components to get a lower BOM, etc. Chinese business looks at cost cutting as the primary goal bar none. Doesn't matter if it impact the specs of these design, unless/until they are called on it and IF they can be forced to pay some sort of remuneration. It is always worth it to keep value engineering a design/product which leads to higher profit, until/unless they are forced to remunerate. There is not a lot of care/f*cks given for 'Reputation' as you see from Japanese, EU, Noram companies.
Talk to some engineers from China, and they will all admit it. They don't like seeing their work cut down to out of spec anymore than anyone else.
One major contributing factor to noisy outputs on many cheap/Asian Aliexpress-alike regulators is poor layout. Take e.g. 8:50 - they use polygon pours to reduce impedance (good) and provide more thermal mass/lower thermal resistance (good), but all the components are still awfully, widely spaced, leaving still considerable inductances, which is especially bad on the switch node, as it has high current ripple. As V = L * di/dt and your L (trace inductance) is high, your di is high and your dt is small, this creates ripple noise. And as layout is something inherent to your PCB (it IS your PCB basically), you cannot easily change the noise created from bad layout.
Even the best components can deliver embarrasing performance if you do not do the layout right. Remeber, electronics is not so much about charges moving, but about controlling and containing your fields. But there are far more talented people out there, which can explain that in much better detail and accuracy.
Great Scott makes a mistake: false noise signals
I make a mistake: *MAGIC SMOKE ESCAPES*
😂
One of the 1st things our teachers told us at LTI is the difference between an expensive VCR and a cheap VCR is a 5 cent component. Like they will use a 1/4 watt resistor to dissipate a 1/4 watt of power rather than using a half watt resistor. Everything today is built down to a price, its the race to the bottom which got us lots of cheap junk.
i liked how you took the images of the components from the circuit and put them in a sketch
Thanks :-)
I think it is because of cost.
Like the MT3608 boost converter, here in Indonesia it listed around 5200 to 6500 IDR (0.32€ to 0.37€). By adding the better ceramic capacitor priced 0.5€, imagine how much it affecting the price.
For me, the initial design is more than enough, reminding the price is dirt cheap. Unless for specific reason I need to modify, like the one you tell about creating negative voltage, I'm set my expectation according to the price I paid 😅
Well, a 20% 22uF MLCC costs 500 IDR (0.03 EUR) on Indonesia's Tokoijo, and the manufacturer would have been able to source it for cheaper. So it's not an excuse.
This man is getting so powerful he will eventually turn a nail clipper into a gun
What?
ayo Heisenberg send a pack of blue stuff
🤣🤣🤣🤣 true.
First hackSmith, then the boys, now great Scott I see you literally everywhere 😂
Aren't nail clippers already declared as weapons of cruelty?
The side ground pin in the oscilloscope probe is a very nice solution. A spring loaded measuring pin would still improve measuring a shivering hand (a so called test pin "needle" for production beds).
Thanks for the feedback :-)
@GreatScott!
In the video (11:11)
you say "2.2uF", the link goes to a 22uF capa... What is right? Or do i just not understand? Thank you!
yeah im confused as well
@GreatScott! In your video you say you used a 2.2 uF capacitor but in the description you linked a 22 uF capacitor.
Which one is correct?
I say 22uf because his mlcc's are really big in physical size.
8:14 i love how you put the images of components next to the schematic components -- for those of us trying to take self learning electronics seriously, it massively helps our brains put to mind the components as if they were legos (but the various values of each 'lego' is like the lego color). Next after looking at this for a while as a reference during test building on our own, the schematic components begin to fit like a catalog in our brains before we even realize it. I hope i not sounding too nuts but this really works for my brain very exceleratredly, ty for this idea and i hope you and others do that much more often -- even if just once before you do the red pen work on the circuit would be a big help ^_^ p.s. i have loved your work for last many years, ty for keep doing your channel ! 😀
Oftentimes, these boards are based around one key component, i.e. the regulator IC. If you were to reverse engineer the board and compare the resulting schematics to the IC's reference design, you'll find probably little to no differences. And very often, the designers doesn't really pay much attention to the textual parts of the datasheet that explains the values and different usage cases, or just use one calculation for all their product runs (i.e. the same capacitors for fixed 3.3V, 5V, 12V and variable variants of the board). Also, the reason they won't add it is cost and availability. They already most likely have tens of thousands of cheap small mlcc caps around, adding one to the output won't change the BOM cost by much, but also doesn't have to affect the output in the desirable way, or even hurt it.
Thank you for showing us this
I always see keysight sponsoring many electronics chanbels but it would be nice if you could make a video how it looks inside one of their mesuring devices (maybe you could get a broken one or something from keysight from their rma or something like that )
I have a bunch of those same buck converters that I'd like to fix, but the links provided are for a 22uf and 1uf capacitor, but the video mentions a 2.2 uf on the output? So which one is correct to fix the final small buck converter? The 22uf link or the 2.2uf mentioned in the video?
Thanks in advance for your time to answer.
Hi, which (de)solderplate you use at the end of your video?
To reduce heat dissipation of lineal regulators consider using an LDO that has only 0.1 to 0.5V drop, and use a lower input voltage :)
A lot of noise I deal with in electronics is 60 hertz noise because all the power supplies use a iron core transformer instead of a ferrite core transformer and the reason why that makes a difference is because all iron core transformers run at 50 or 60 hertz well ferrite transformers run at higher frequencies. And 60 hertz noise is very noticeable if you're using inductors and highly sensitive electronics
You have quite an assortment of nice tools, that and the knowledge to use them properly makes all the difference
When switching to the MLCCs, why the smaller capacitance? Is it a limitation of what's available or do you not need as much capacitance when the other properties are better?
I'm interested to know how you came up with the value of 2.2uF to add to the output. I myself am struggling with some buck/boost converters.
As a guess it was the largest commonly available capacity for the needed voltage rating and component size he decided on. He might have took the switching frequency into consideration but can largely be ignored if the original design worked at all.
What's the names of the type's of test probe's used first at @2:33, the one in the background it pushes open and hooks against the wire lead and then closes to make a sure it cant short on anything..
And then again a different style tester probe with the positive in the center and then a ground lead coming down from the side, @4:34 ?
Thanks!
I love that hot plate for component removal at the end.
Great walk-through of the process as always
Thanks for sharing your experience and solutions with all of us 👍 😀
0:01 VTEC just kicked in, yo!
Thank you very much for the video. How could you make the UPS not charge the battery at such a high voltage? For example, charge it only at 4.1v to increase battery life. Thank you so much
'If your PCB design is garbage' - had me in stitches, hope the sellers of that circuit see this video and take note!
This was a very interesting and also useful video!
I found especially interesting the bandwidth limit on the oscilloscope. Can you make a video to explain why it's limited during official measurements, the implications about having strong peaks beyond that bandwidth limit and how to absorb them if so desired (I know this part: ferrites rings/beads around the wire).
Thanks!
Is there any video or explanation how you can cool something down by adding more capacitors
I actually got the UPS from the last finding hidden gems video and it works really well
Glad to hear it :-)
@@greatscottlab I did too. Can the same value caps be used when the output is 12V?
I also want to know. I bought 2 of each, 5V, 9V and 12V, for alarm/cameras and just in case. One seller has it for 4$ each and there was also 1$ from 5$ coupon for playing (and losing) in Go go match game, but this promo ended. So they were really cheap.
@@oyvindrepvik I think so
Well mt3608 module comes with 10uF MLCC on the output already, just wondering how does 2.2uf additional cap could make such difference in noise reduction ?
Another awesome video! In the video you said 2.2 uF ceramic capacitor for the mini boost converter. But the website link goes to a 22 uF ceramic capacitor. Is it meant to be 22 uF or 2.2 uF?
The modules I have seem to already have input and output caps of around 28uF, so I can only assume he means 2.2uF.
Can you please tell which hot plate you're using here 11:30? Thanks
6:56 adicionar um LM7805 não acaba com toda e eficiência do produto ?
Yes, ist does
50 cents can be a lot on a large scale production. Aluminum caps are easily replaceble and do less damage the board than the ceramic ones when they fail.
what is the power of the Soldering iron you have to use for the PCB's Replacement operations?
I ordered the parts from Mouser, so now the two UPS devices going to get the upgrade. I even have 5 of those boost converters to that I will do the same with.
Thanks for this great fix video. Great stuff as always. Now I just need to find a cheap-ass oscilloscope, so I can test other electronics I have lying around.
Does anyone know which video Scott introduces the load controller at 2:41?
About the UPS:
Is it possible, that there are no MLCCs at the output? The elkos have a too high esr to filter the output voltage. It could be worth a try, if there is a suitable footprint close
Oh interesting - I have some AliExpress modules with caps that get hot. USB-C power modules I use in power banks. Is it a pretty safe upgrade to just replace the electrolytic output filter caps with multilayer ceramic caps with the same uF value? Is there value or risk in going with more uF?
just ordered a few of those ceramic caps, i do like using those nifty things. Do you reckon it would work on a custom PCB that is based on the MT3606?
Hi, would you replace the same capacitors for the 12v UPS board?
what is the name of the hotplate you used for desoldering the UPS in the outro?
Can you make a video about the D3806 voltage regulator? Is improvement needed?
Two 100K ohm resistors, a 2.5 V reference diode, and an OpAmp and you can also get a very stable 5V with current up to the opamp’s output current rating. Also, thank you for admitting a mistake, many wouldn’t be willing to say that, very cool!
Hi, GreatScott what's the device with the pcu fan red, can we test battery capacity with? Thx for your answer !!
Do you have another link for the 5V UPS, please? The one you supplied seems to be dead!
Great video! It's amazing to me how often a single capacitor can fix big issues in electronics 😁
I used to do component level troubleshooting for a manufacturer of cable tv monitoring equipment. Here is the answer to the question of why don't they use better components, at least for them. Their engineering team used 1% tolerance parts when designing and prototyping. They would hand off the list of components needed never specifying what tolerance (if any) of parts should be used.
Naturally, procurement bought the cheapest stuff they could find. I practically begged management to let me talk to the engineering team. They finally brought one guy down. I sat him down, showed him the log I had been keeping, and the exact parts that needed tighter tolerances. In this case it turned out to be the inductors in a frequency generation circuit.
The board pass/fail rate jumped to over 70% (it was in the upper 50's). My big reward for figuring that out was I got to be the end of the line guy. If I couldn't fix it, it went into the trash. I didn't last long there
Respect for owning up to your mistake and educating others! Thank you!
The sign of a great engineer is admitting that you got something wrong.
Experience is the polite name we give to our history of mistakes.
Well... I've got some of those mini boost converters and i already knew that something wasn't right. Only a small SMD capacitor on the output. On my projects when i used those boost converter modules, i always added some extra capacitors on the output (Both electrolythic and MLCC).
DC-DC converters are INCREDIBLY useful in basically everything.
I wanted to ask if you can make a video where you analize a 'special kind' of DC-DC converter, the one used in ALL car audio amplifiers: A single rail to double supply rail DC-DC converter. I could not find any appropriate schematics anywhere. This DC-DC converter is really useful but i just cant find a way to make a proper DIY version. A lot of people is probably searching a way to make this DIY... I think that a video about this topic will explode on views! (And help a lot of people too).
A DIY version is really versatile, because you can have full control over both the output voltage and the power that the circuit can handle. It would also be a nice learning experience.
With this circuit, a battery can run ANY audio amplifier!!
At high frequencies such as in these switching power supplies, standard electrolytic capacitors have too high of an “equivalent series resistance” (ESR) and should not be used in this type of application; that ESR leads to excessive heating. Low ESR electrolytic capacitors are designed for these applications.
The small ceramic capacitor heating up is a bit surprising since they are intended for use with high frequencies; perhaps that was a cheaply made part, and that is why it showed a higher than expected temperature.
Or the ceramic one had to do all the work and was more or less "overloaded"
Does showing an unblurred picture of a ceramic figure on UA-cam qualify as graphical violence? LOL!
😂😂
Hi, what would happen if you use a higher voltage input for a boost convertor above it's input limit. Would it malfunction, or would it keep the output voltage to the set output?
one question, that capacitor fix for mini boost converter. what is the limit voltage for that fix, i see in the description that is 10v capacitor so what about 12-15-18v dc?
Yep. If the cap only does 10V then 10V is the maximum. Simply select a cap with a higher rating.
can i use 10uf 35v tantalum capacitor instead of ceramic capacitors.. i dont have ceramic capacitors but i have tantalum capacitor
Where can I get the surface mount solder hot plate you showed at the end?
BTW, good on ya, for showing the error in probing technique! It is *such* a common issue that it's kind of like "is the power plugged in" question for oscilloscope AEs !
I have a similar boost converter from Ali that already has a capacitor installed at the specified location. They're advertised as being able to boost up to 28V but none of them went above 19.xV, sadge. I wanted to use them to deliver a higher voltage to 24V fans T_T. Any quick fixes that come to mind? They are of the MT3608 type with USB-C in, rated for 2V-24V in and 5V-28V out.
will the buck-boost converter work on a psu from a computer? I'd like to use the 12v on psu to power the buck-boost converter
Hi, thanks for the video, just want to ask: what is the size of the booster capacitor that you use? the 1206 or the 1210?, thanks
Sure this will get lost but what tip do you have in that iron handle….I have same handle and right now I only have tiny tips awesome for smd work but it’s just not enough thermal mass for bigger stuff… what you had looked perfect
They might just do that now. We are constantly reinventing the wheel and working towards making something as efficient as possible. Thanks for the videos you put out man it has significantly added to my progression of circuit design.
Why did you blur the xorxuits while filming the soldering operation?
Thank you Scott I have that exact same boost converter now I have to just add that capacitor in parallel to my output terminal. Love your videos 😍😍
I have some experience in real market production and can take an educated guess to why such things occur:
Case A - The Manufacturer is not aware of the issue due to one of the following:
1 - prototype worked well but somewhere in production someone deviated from the design due to the lack of some component
2 - a partner provided a batch of bad components
3 - lazy (minimum testing) or non-existent QC
4 - following (copying) a design blindly not knowing how slight changes might affect the result
5 - Damaged components due to bad quality / bad storage
Case B - The Manufacturer is aware of the issue:
1 - Greed
2 - discovering the issue in late stages of production (happens a lot) so they lower the price to not throw away the stock and to avoid fixing the issue which is sometimes very hard to near impossible / costly
3 - they just don't care
4 - indented for uses with high tolerance to error
Could there be issues with capacitance in case of using inductive loads? Maybe they ring or behave strangely if you use them with steppers?
That should not be a problem.
In my opinion a part of noise came from the switching elettronic load... Try to add a capacitor on the input of load.
06:22 Additional to further reduce output noise, add capacitor parallel to R1. Start with say 0.1uF. This will inject output noise in feedback path & can help reduce output noise further.
that makes for a PID controller, you are injecting a part of the noise in the PWM regulation which could create instability... If the dynamic regulation is OK, you should not touch it but improve output filtering IMHO
@@adrienletellier6132 Yes that is why capacitor value should be specific based on output noise.
Can you please test de peak current on the input of those booster boards?
They seem to put high amps for like some milliseconds at start. I fried some 7805 by feeding the input those boosters, they were tuned to output about 8V for a small
@4:22 / 5:24, what is the thing with the fan on it?
This is not a complaint about this fantastic video on what can be done to achieve better results from inexpensive switching power supplies, just a reminder that buying what appears to be inexpensive component parts can be very expensive when you come to pay for them to be shipped to you!
50c for a component is a great fix, but let us remember that no component supplier is going to ship you a 50c component for free, most suppliers have a minimum order price + shipping, which can make small projects VERY expensive to build.
This is even more frustrating here in the UK where buying let us say GBP 10.00 in components can result in you paying GBP 10.00 in shipping, so when you want a GBP 0.50 regulator you have to either buy 100 off of them or pay the minimum order charge plus their shipping.
Sorry for the whine, but a lot of UA-cam videos on building small electronic items forget these hidden costs.
Awesome! Ordered the power supply. Thank you so much for testing 👌
You're welcome ;-)
I did the same sinc my Bugconverte Cap was acting as SC because of ESR i realised ceremic might be good option since it's easy to find from old motherboard or pcb .
What is that hotplate you used at the very end of the Video?
Hi Scott, I was wondering if you could do a video to show how to connect a VFD with a single phase capacitor start motor. Thank you
Replacing the output capacitor with a low ESR one reduces noise, but also the power supply ripple. Often that ripple is needed for stability of the voltage regulator. I would always recommend to stick with replacements to similar components and not deviate too much from the original implementation, unless one can measure the stability afterwards. Bad stability is often much worse than noise.
I bought the UPS circuit in 5V and 12V versions, but I've received 9V instead of 12V, so from this video I've easily recognised the resistors to swap for the voltage divider, but buying the exact components is not feasible due to the shipping costs, so I went to the harvest route. The problem is that my multimeter is not very good at measuring resistance, so I harvested some similar resistor from another circuit that had similar resistance without really knowing the exact number. Well the good part is that I managed to obtain 7V, 10V, 13,5V and 20V and left it at 13,5 that is the most similar (also should allow more power and staying close to 12V during high loads). It will be useful to know the exact resistance, maybe you could pick it up again and make a couple of final upgrades: a potentiometer to regulate the voltage and an interruptor to disconnect the batteries when not needed. Maybe design a cool box 🙃. Having a clean output is not always critical, especially if I know such regulation is done at the receiving end.
Just received mine, a 5V and a 12V. Will be using 1 for a solar project. Just be careful with the voltages! Capacitors seem rated at 16V max and I would stay at least 10 to 20% below that. Checked my 12V version and that smd resistor R7 has a marking 9092 which is 90.9 KOhm or 90.900 Ohm. Also the board has been changed as his has R7 and R7* . The R7* has turned into R12.
I would always opt for a clean output. Spikes can produce noise on radios if you use longer wires and in some cases cause strange effects. I always also place a 100nF cap on the input and output.
a few seconds in the end of video, I see a beauty pcb heater. please tell me it's model? thanks
So when replacing the capacitors does the rating not matter because of the design difference?
Hi,
Can anyone tell me which value of capacitor we need to use for which application?
Thanks