You'll want to use a 10x38mm PV fuse there. Auto blade fuses are a fire hazard at those voltages. 10x38mm PV fuses are ceramic fuses with, roughly 1000VDC ratings and very high interrupt ratings (40kA+). Usually sold in increments up to 30A or so.
Thanks for the comment! Lots of you guys mentioned automotive fuse is a no no - absolutely right. This is just what I had kicking around my home office. I have lots of WGPV-30 fuses at work that I will use for the final install. Realistically, i should have made the trip to get them for this test. Next time 🤞
@@leckiestein Yes, those are excellent fuses. 1000VDC, 33kA, 10x38mm ceramic PV fuses. Also look into DIN-rail mounted fuse holders to help organize the bits and pieces. Size fuses to 150% of your maximum expected continuous current to avoid overheating them, and within the cable spec. Also check the fusing on the Tesla battery pack. When you are ready to tie it in, you might need a T-Class (200kA) first-stage fuse given the amount of energy it packs. The pack might already have one built-in somewhere but since you are likely using the modules individually you are probably bypassing it. So you'll need a T-Class (200kA) main battery pack fuse before you tie it into a bus. Victron now makes busses with T-Class holders built-in that are very convenient for something like this. Victron Lynx Class-T Power-In with M10 bolts. Not cheap but probably necessary. -Matt
Fun experiment! Thanks for sharing. Yeah you always have to take the chineseum ratings and convert them back to real ratings. Monitoring hotspots (surfaces of mosfets, etc.) and setting limits or improving the cooling as needed. You probably would have had a better chance at success if you went with the 24v output. 5v at 50A from 90v is an extreme conversion and would require double or triple the inductance or capacitance than it probably currently has. I had done a different test with a bit higher quality buck converter. I tested the output current with 24v in and a short on the output. It was surprising that the capacitors were getting really hot and not the mosfets. Certainly interesting stuff indeed.
I bought a couple of these but haven't used them besides basic testing. Unrelated to your test but interesting: They are synchronous buck converters so if you back feed on the output, it boosts the voltage back to the input but it doesn't have input over voltage feedback so it goes max voltage until the input caps blow. But we can use the icharger or others that have a recycle feature so when discharging a lipo, you can send the power back to a higher voltage big battery bank.
That little guy obviously has no ability to sustain 50A of output. Good call on the fuse. The power supply shorted out.... the FET probably died. Generally speaking when diodes and FETs die, they die into a crowbarred state. You can't use a regular vehicle blade fuse to protect an 80VDC source. That fuse could easily have failed and turned into an ARC fire. You can get proper power supplies with output over-voltage protection but if you are looking for something with a wide range of input that's a bit of a different kettle of fish. My solution for random high voltage DC inputs is to actually use a solar charge controller and a small LiFePO4 buffer battery. Fuse/breaker, charge controller, battery. I use the charge controller to trickle-charge the battery and the battery provides us with some bus protection as well as the ability to sink a lot of current at the lower voltage (just not continuously 24x7 since it is being trickle-charged). An example of this would be, say, a 10x38 ceramic "solar" fuse (these are high voltage / high IR fuses), A Victron SmartSolar 150/35 charge controller, and a small (12, 24, 48V as you need) LiFePO4 battery with the current capabilities you need for the equipment. In this situation, the charge controller would be able to charge at 35A. So 12VDC output x 35A = 420W, or 24VDC output x 35A = 840W, or 48VDC output x 35A = 1680W. Something like that. Voltages will actually be a bit higher to properly charge and float the battery. A 25.6V LiFePO4 batteries is charged to 28.4V and floated at 26.8V. Plenty good enough for 24V gear. For example. And you get a ton of proper safeties with a real charge controller or DC-DC instead of the fly-by-night amazon model which has zero safeties. Note that charge controllers do NOT have well regulated outputs, hence the need for the battery is mandatory. A Victron (or similar) DC-DC would have a well regulated output without a battery, but has a more limited input voltage range. p.s. does that power supply even have an input fuse of its own? It should have one on the board somewhere. If it doesn't it's a fire hazard that wouldn't pass any certifications (whether it lists any or not).
In my QA & repair job at a tech firm 20-30 years ago, we used Cosel power supplies . Never really looked inside one, because THEY NEVER MALFUNCTIONED. Those were the days
@@leckiestein I don't know how they get away with it? I had a bunch of voltage controllers from China about 10 years ago, ALL of them broke down well within HALF the ratings. I wince every time I see these solar folk and other project makers use these dangerous at times garbage things! There must be a lot of editing out of the woes of these units constantly failing. I thought you did well with your one here though lol, 70% surprised me :)
Hello, you wrote the use a Single IRDZ44 as the Switcher, On Pictures on the Web I see there are 2 Mosfets used , this seems to be a Synchronous Design made by a TL494 using it in the Single Output Configuration + an Half bridge Mosfet Driver that Drives the Low and Hi Mosfets, can you please check if from the 8pin chip there is a Path to the Gates of the Mosfets (through the Smd Transistors) ? Thankyou, Konstantin
Oh interesting! Maybe you can send me a link to the photos you're looking at? My converter is plastered with silicone and I'm sending this back to get a refund so I don't want to damage it trying to pry it up; I didn't actually pop off the heat sink to confirm the device it's likely the part number is etched off anyways, but I'm confident the transistor used would be no more than what a Z44 can handle because there's only two devices under that sink using what looks to be a TOLL package. They would have to be rated for at least 120 V and I don't think you're going to find anything at that voltage much more than 50 A in a TOLL package. Z44 is the first part number that came to mind but now that I think about it I believe that transistor is only rated for 60 V. Anyway, interesting that you mention it's a synchronous converter, I do see two traces and there's two transistors leaving the driver heading under the heat sink and I was wondering what the secondary trace was. If this is a synchronous converter that trace and extra transistor makes sense but that would mean the driver couldnt be a TL494 in that case. In order to use a TL494, you would have to use a gate driver such as a UCC27211 to handle the high and low side mosfets. I 100% don't have that on this board. So the big question is: what that heck is this Driver?!
Hi, the Photos are from Aliexpress where the Bottom side of the PCB is shown and there the Pins of are 2 through-hole Mosfets can be seen (just see the Botm of your PCB :-), either TO220 or TO247 donno. The SOIC8 Chip in my opinion a HalfBridge Mosfet Driver with integrated Dead-time like the IRS2184(but probably a CN Clone of it, I use these clones too) and not an opamp. The TL494 has already 2 Error Amplifiers integrated an one can be used for OCP. Btw., what is a TOLL Package ? Mosfets can be for ex. IR IRFP90N20D 200V 94A or HOOYI HY1920P 200V 90A or probably some CN part with similar data, the IRFZ44 is ancient and way underrated :-) A Similar Circuit CN DCDC Converter I have (just mechanical different and upto 75Vin and only 25A out) uses 2 HUAYI HYG043N10NS2P 100V 164A.
I don't know if this applies, but I fried a similar "400w" boost converter going from ~12V to 14.5V at around 7 amps. It fried as I was connecting/disconnecting the load after a few seconds of test - I think there was a feedback thing happening. I added an 18V "TVS" diode to the output, so if I do get a spike, it would get dissipated instead of frying something. After that modification, I didn't run into any more issues - its' been working great ever since.
In my experience what they do is quote a power but that power is at the least conversion so the highest output voltage so if it was a max of 60v output then the max current would be around 16A which would give a max output at 5v of 80W. I think it's deceptive to give a power rating on a variable output device as the limiting factor is always current. I know it's not quite that straight forward due to the PWM but I have many boost and buck converters and this current limitation always seems to hold true for the ones I have blown up. The same is true for MPPT converters which are quoted, more correctly, on output current and input watts s increase as the system output voltage increases so a 20A controller on a 24v system can handle twice the watts as it can on a 12v system.
Generally I've had a lot of luck, too, with buck boost converters meeting the ratings given. Usually once you get to the top end of the spectrum heat becomes the problem therefore duty cycle has to be limited. But in this case this unit is just completely improperly rated. The transistor used is only rated for 50amps. When you are switching at high speeds on an inductive load, transient currents can be three times this!
No. It might say this watt there or that watt there, but the specification literally says 50A on max output. You may then combine those 50A in anyway you see fit as long as you dont exceed max watt. As an example, 1000watt. So, if you want to charge a 500ah lifepo battery at 14,6v and 50A then you can do that. Except it blows, because they lied.
When I said switching high speeds on an inductive load I'm referring to the inductor used in the converter, not the final output. The initial circuit the transistor is connected to is a reactive circuit and they did not account for the transient currents that occur when switching at high speeds on a reactive circuit. The transistor should have been at least three times the rating. So yes, they grossly overrated this unit.
@@leckiestein I accept certainly that it is over rated. My comment was more observations about the ones I have seen. I do wonder if it might manage higher current with minimal reduction in voltage say with input at 60v and output at 55v although that would be too great with the transistor you say is used.
@@philbrooke-little7082 I can parallel 3 mosfets and that would likely do it. and you're right, if we can get the voltage difference to be smaller, the amount of energy needed to store in the inductor would be greatly reduced therefore increasing the reliability of the converter. However, the topology of this converter is problematic for sensitive work, if a transistor fails, it shorts the input rail to the output rail. Im making more videos on this topic as I carry out my work of fully battery backing up my entire print setup. Ive used the power designer tool from TI may times in the past to design power supplies so Im designing my own converters using a synchronous rectifier topology and this can achieve 99% efficiency.
My default assumption is to de-rate any questionable electronics I get off Amazon or Aliexpress to half of whatever they're advertised at, and potentially adjust downwards further based on thermals or component choices. This is still pretty affordable for a 500W/25A converter, but it would be a lot nicer to not have to second-guess whatever numbers the manufacturer sticks on the product page.
Nice video, these amazon converters are often over-rated, I have had good luck with some by running characterization on them (primarily investigating stability with increasing load, feedback and output signals on the PWM controller) and using them well below their "rating" once that is understood. I have also had luck modifying feedback components or adding low ESR capacitors on input / output rails. Of course, that's a lot of time invested to work around the cheapness. One additional note, most blade fuses are rated for 32V, so they may not provide protection reliably in this scenario (80V,) when breaking higher voltages the fuse can sustain an arc or even plate out internally preventing it from interrupting.
Hey thanks for your comment! Making sure we stay safe out here. The Automotive fuse is just what I had laying around as this is just my home office. But at work, Ill be sure to use a littel or Bussmann High-Rupture Capacity fuse when doing the final wiring :)
Hi there! It comes down to what is most cost-effective. So the idea is to have a single server rack house 20kw worth of power supplies including a 72v battery. Each printer rack needs roughly 2.2kw for 12 printers and runs on 24 volts. The average distance to run wire from each print rack to the server rack is 50 feet. If you do the math: To deliver 2.2kw at 24 volts 50 feet away with min voltage drop, I would need 100 feet of cable, and nothing less than a 0 awg pure copper would deliver to the site with minimal voltage drop. I currently have 7 racks so that's about 700 feet of zero gauge wire needed. At $11.50 CAD per foot * 700, it would cost me $8000! If I run high voltage with a DC converter at the print rack, the wire can be 12 AWG which is $0.60 per foot and I will have exactly 24v at the rack with a converter since voltage drop won't be an issue as the converter can compensate for the difference in input voltage. Make sense?
How do the existing printer power supplies actually behave when fed with HV DC instead of AC? Can you distribute the backup to be at the point of use? AC's advantage is to be able to easily change voltage for lower amperage transmission. There exists a distance at which transmission in AC becomes cheaper. In this use case, you can use the cheaper "off grid" inverters since you are not feeding power back into the grid.
I have some meanwell supplies currently running my Print farm that can handle dc and ac input but im far out of the operating range. I believe the low and threshold is 160 VDC
@@leckiesteinI would use paralleled modules to run a 240V inverter (or 120 if you like) and distribute that, then use the printer’s PSUs as normal. Cheap and simple and safe.
If I wasn't planning to make videos of the engineering and building process, absolutely! But, Id like to grow my channel with unique content. Connecting batteries to inverters has been done to the 9's. I think people will be more interested to watch the experimental/development process while giving me the opportunity to utilize some expensive gear I already have and its a great practical learning experience for everyone :)
As soon as I saw you pushing the amps up I new it would fail I have some similar units and in the instructions they indicate the current at such wide voltages has to be reduced and they note a max current at the output which is about 30 amps and my units say 1500 watts they also have fuses installed.
5:15 use parallel Diode for each battery pack . it will be good to protect reverse voltage and forward the voltage when one of the batteries is in voltage cut-off stage.
@@vgamesx1 You should also have an undervoltage shutdown at the downstream load so that if one battery disconnects, the load disconnects as well. If your load is a power converter, it will generate a massive current spike, as soon as one battery in a series connection drops out. Imagine drawing 1000W with 4x20V batteries and all of a sudden you only have 60V instead of 80V, but the load still draws 1000W. Current would shoot up from 12.5A to 16.7A. If you only have two batteries, the current would likely double. So the rectifier diode needs to be sized for the current to be expected at the lowest possible working voltage.
My assumption is that the "most false" part of the advertising are the 50A and not so much the 1000W (maybe this can deliver 500-750W with a higher output voltage like 40-50V). Also I think the spike from the sudden change in the DC load was quite bad for this unit, as you said it does not even have ceramic capacitors so big spikes might occur when that expensive DC load changes its apparent resistance in microseconds each time you turn the dial 1 click. Maybe I am wrong, but I want to be totally fair with the unit. Very instructive video. I will probably not purchase that unit, however, when "chinesium" is involved I usually tame my expectations to about 1/2 of the advertised specs. If not less. Even if it is not ideal for me the usage of this fuses not rated for 80V is not as concerning as some comments say. Maybe for industrial usage it is, for a controlled environment, I do not expect them to arc like crazy at that voltage levels even with high temperature and so on. And it is better that than nothing. Cheers.
Many switching power supplys can run on dc for example 110v dc so maybe you can add another battery to get around 100v dc and try few models of power supplys to see if they work on dc. Probably the original psu's of the printers can do it
Absolutely, and thanks for the comment. Back in 2019 when I started building my print farm, I did consider this so I purchased Meanwell rsp-3000 power supplies and they can do 165vdc - 270 I believe. Anyway, I have 9 of them running my printers right now. The plan was always to get a model Y battery back when they became more available and split the pack in half which would be 200 volts. This plan was formed before the recession. Now the 3 phase high voltage power supplies and the batteries would cost more than all of my printers put together which the majority of the farm is bambu A1 minis. These printers also require half the power of the original printers so all in all, I dont need as much battery as I once did with the ever-evolving 3d printer of today and Id like to use what I have to save that money to put towards more printers
@@leckiestein Yes, though remember that Mean Well is a premium OEM. Their supplies have more safeties than you have fingers and most are fully rated for both AC and DC inputs. It all depends on the design. Cheap power supplies often have a transformer to reduce the AC voltage BEFORE going into the rectification stage and cannot handle a DC input (a DC input will just short-out the transformer). They do this so they can use cheaper low-voltage components. Premium power supplies have high-voltage rectification and/or switching circuitry BEFORE the transformer. Particularly power supplies with PFC circuits. These can theoretically handle AC and DC inputs.
That is kind of what I am researchig about. I took a risk and powered a network equipment cabinet at 300VDC. There were ubiquiti, Mikrotik, TPlink routers and network switches in that cabinet. The equipment has worked flawlessly for almost 3 years now and still going.
@@collinsmwaura1833 The fuses and switches and any AC relays in that equipment can't handle DC ARCing though, especially at 300VDC. You've created a massive fire risk by doing that. I do run small devices directly from LVDC in a few places that I need to backup. Like a network switch or cable modem. If their power bricks output 12VDC then I can just clip them out and run them from a fused 12VDC battery system, for example. -Matt
That flashbang was probably due to the load dump when the DC load tripped. Being too careful and you probably forgot the load was only capable of 30 amps.. All the same the components look more like 200 watt than 1000 watt capable.
I'm confused... I can't understand why the fuse popped... You were draining about 2 amps from the battery, the fuse is 25A.... Why the hell it popped? Do you means that the high power MOSFET shorted and caused an high current spike? Anyway NEVER NEVER NEVER trust the specs about batteries and converters sold on Amazon or eBay or AliExpress... The Chinese manufacturers and seller are ALWAYS EXAGGERATING THE SPECS, like the power banks with a 5Ah battery advertised like a 20, or like you experienced , a 150W converter advertised like 1000w. I learned the lesson: always think that the real specs are about 10% of the advertised one...😂
Hey thanks for your comment. Ya, its crazy, there was only about a total of 3 amps worth of current running through the switch transistor before the fuse popped. A few things could have happened: the amount of flyback voltage on the transistor could have been too high causing the short because I really doubt there was too much current or the current on the rectifier was too high causing the rectifier to short. Either way, I had it replaced and Im going to give it another go under different conditions in a coming video!
Thanks again for sharing, I just came across Your channel and I think I´m gonna stay. Your setup is awsome, everything is right at hand… I consider myself a tinkerer, too but I am not half as sophisticated. My next goal would be to create some kind of voltage standard to check the accuracy of my gear, But there´s a hen/egg problem: how do I check accuracy with "unknown" gear? I recently aqired a Metrawatt MA 5D meter, it can do all I need: volts/amps/resistance and capacitance. Now, the company is not interested in repair anymore but they want me to get new gear that I can´t afford. So I go on the usual suspects sites to look for something I can. Now, I checked against known parts and the Metrawatt as my Voltcraft tell the same so I feel safe there. I want to get into tape decks & stuff where milivolts matter, now I think I can. Have a good day Mate, You and Your loved ones be safe.
Hi @LaLaLand.Germany, Thank you so much for your kind words and for taking the time to share your journey-your tinkering setup sounds impressive, and I’m thrilled to hear you’re enjoying my channel! Having a reliable voltage standard is such an interesting project, especially for fine work like tape decks where every millivolt counts. It sounds like you’re already off to a great start with the Metrawatt MA 5D and the steps you’ve taken to validate its accuracy. I completely understand the challenge of finding affordable yet reliable equipment. That’s actually one of the reasons I enjoy diving into bench testing and sharing projects like these-making high-quality tools and knowledge accessible to everyone. Speaking of projects, I’m excited to share that this channel is now sponsored by JLCPCB, which opens the door to some awesome upcoming builds! I’ll be designing and testing custom PCB projects that I think you’ll enjoy- lots of power supply projects and everything from innovative tools for tinkerers like us to creative ways to solve everyday challenges. Thank you again for your support-it means the world to me. I’m looking forward to seeing you around the channel, and I hope you and your loved ones stay safe and well. Have a great day, Mate! Cheers, Leckiestein
When you are doing 'tests' totally out of specs of the parts/components, you can expect this kind of results and more. Probably ablet to do a peak of 15 Amps at 80 volts or such. But really a peak like for half a second with a low duty-cycle like once in an hour and normal load max 5 amps output. But with 5 V. out, probably max. 25 W for a bt longer time with an input of 30 Volt. If you cannot find the specs of the total design, the components and tracks will give you lots of clues. For your way of fusing.... to protect the batteries and cables, better use something that can handle this voltage to cut. Also, add fuses and some kind of smoothing on the input . If you had put an oscilloscope at the input, you would probably have seen sad loads and voltage-drops too due to the high voltage-differences you had during the short test. Actually, the peak currents through the battery-packs might induce problems on the protection-circuits inside the battery-packs very fast too. They are designed for much more constant DC-loads then the high-frequency load you have put through them. Using packs like these straight on the input of an inverter can also ruin the converter. Converters like these can probably work much better on normal lead-batteries. Just imagine the high currents during the small peaks on the inside of the converter with 1% or such on 10Khz for example.
As you got that error message from your load, that it was going to disconnect, it seems that the sudden loss of load is what destroyed that cheap converter. This seems to be a design flaw with your load, it should have not disconnected, but instead just limited how much it was drawing. Many switch mode supplies have a minimal load spec, and suddenly going from heaps to zero at a ridiculous speed (like opening relay contacts) can kill even the best of them.
The electronic load disconnected because the converter switching transistor shorted thus the input was shorted to the output. The electronic load suddenly received 80 some odd volts while trying to pull 34 amps. 80*34= 2720watts. The electronic load is only rated to do 350 watts max.
Listed rating on internet shop? Apply safety coefficient of 0.2 on what is listed, then you get real value. They remove those markings on smd, not to prevent cloning of device, they do it to prevent claims and reclamations that people will recognize immediately device is not within spec. Then you turn it on, burn it maybe and thats it no reclamation.
The way i understand the exaggerated/misleading "1000W" is as the area of the operating envelope: (Vin-Vout)*Iout. 75v*20A = 1500W; 50% more than rated. OTOH, with that size heatsink and fan, I'd guess it was good for about 50W dissipation. If we call it 95% efficient, then about 13A would be the max (48.75W) for 75v/5v, and as it so happens, that correlates with ~1000W.
Hey! What's the model number, Ill have a look! Im actually in the market for something to charge the batteries on my enclosed solar trailer (coming in a future video).
@@leckiestein @leckiestein RSP 1500-24 - I noticed you're a CA resident. That would make the exchange difficult imo; but if you're still interested, lemme know. I thought of running all of my 24V 3d printers off one PSU. I imagined the cost of the 8awg fine strand wire going to each machine (2 Voron and 1 Creality) would be too pricey. It would be worth it in a 3d printing farm, maybe.
You would be right! Were trying to store so munch energy in the inductor. My thoughts on doing this was to run an initial test before wiring it to my expensive electronic load in series with a battery. I received a replacement converter so keep an eye out for the video - ill be testing at 24 volts.
@leckiestein awesome! I've looked into these converters specs in detail.while they are a bunch of junk to me anyway,lol,I'm gonna give one a go to see if it will power my new solid state high voltage multiplier sometime next year.i need 3 to 18vdc at 35 amps.i love linear supplies but there's too much power dropped across them, when u drop the output voltage.worst case is the converter will smoke and I'll have build a fifty pound linear supply that won't turn down as low.anyway great video.id set the input at 60v roughly and sit 20 to 30v on output.put 20 amp load and cross your fingers.hope for best,plan for worst.lol.ill look for your video!!best wishes.
Hi there! It comes down to what is most cost-effective. So the idea is to have a single server rack house 20kw worth of power supplies including a 72v battery. Each printer rack needs roughly 2.2kw for 12 printers and runs on 24 volts. The average distance to run wire from each print rack to the server rack is 50 feet. If you do the math: To deliver 2.2kw at 24 volts 50 feet away with min voltage drop, I would need 100 feet of cable, and nothing less than a 0 awg pure copper would deliver to the site with minimal voltage drop. I currently have 7 racks so that's about 700 feet of zero gauge wire needed. At $11.50 CAD per foot * 700, it would cost me $8000! If I run high voltage with a DC converter at the print rack, the wire can be 12 AWG which is $0.60 per foot and I will have exactly 24v at the rack with a converter since voltage drop won't be an issue as the converter can compensate for the difference in input voltage. Make sense?
I built a display in a showroom using addressable LEDs; the entire display is about 150 A at 5 V. if there was a situation where someone wanted to run addressable LEDs from a lipo battery, this would be a good option (if it doesn't short out first lol)
You used the wrong watts, we found many years ago that far eastern 'seller watts' are approx 1/3 of a 'standard electrical unit watt'. after lots of testing and measuring that conversion factor from 2006 still seems accurate to this day...... This unit was a let down, i expected it to smoke about 400w going on a guess from its physical size. Its maybe been fitted with a cheaper mosfet in the chopper stage. it may be worth fitting a new 100v rated one in at as many amps as you can get in the package size to fit the original pcb, you may find then it actually is a moderate board. Once I bought an inverter that had a bad fan, it smoked, returned for replacement that did its 2000w, but smoked after its 3rd morning coffee brewing in the camper, they refunded and said dump it, i took the refund and replaced all the fets with decent ones, ones in it were 500v 30a as they should have been but a different part number by 2 letters from the pcb, different manufacturer and while the amps/volts matched, the package total watts didnt (250 not 395), i guess they substituted on volts/amps onlly and not watts, and guess they will have got many returns for a design that was good if they built it to spec. its 7yr old now...
@@leckiestein No, no i'm not lol..... far eastern seller watts run about as true as far eastern seller mah's on rechargeable batteries.... you cant even buy a 10w led bulb that runs at 10w from any of the big online sales buckets...... anything bought on banggood, ali, amazon affiliate seller, ebay, you cant trust it, you may as well be buying from temu or wish. One thing learned over the years, buy on footprint area, buy on mosfet count, buy on weight, dont buy on published seller claims.... only good thing about that mystery box is the tl chip in it, at least thats maybe ok and so replacingg the mosfet's or output diodes is maybe possible, to make that 1000w supply ok. (well 300 real watts in that footprint)
TLDR choke smps arent wattage limited but rather cureent limited and voltage limited, and current cannot rise inside choke, so if you want 50 amps at output then it needs those 50 amps at input at lower duty cycle, thats why high power buck converters REQUIRE very good input capacitors. So obviously you cant get 1000w at 5 volts from this humble unit - even inductor is probably going to saturate despite being black kool mu - it has way to many turns for 200 amps. For real power you need special stuff like whats used for CPU/GPU: high frequency to have small inductor with less turns and thicker wire, multiphase if difference in voltages is too big (since its directly affects duty cycle which you cant make too small without sacrificing efficiency) and so on. For that thing I expect current limit to be about 20-25 amps and it could in theory handle it well.
@leckiestein thats not how buck converter works, if you want 50 amps at output then you need 50 amps choke current. Voltage difference is t_on/t_off. So even with 100% efficiency you draw 50a*80v for 1/16 of period, then release 50a*5v for 15/16 of period.
@@TURBOSLAYERPWNZ Please know the difference between passive and reactive circuits. Whatever POWER (not current aka amps) comes into the converter, it will be the same power that comes out of the converter minus any losses that happen during the conversion process aka resistance in the inductor, switching mosfet, rectifier, board traces, etc., that create heat.
@@leckiestein It seems that we are talking about different stuff. You are talking about what comes in and out of converter on AVERAGE, while I am talking about what happens inside and stresses its components at different moments. Converter has parts that store energy - inductor and capacitors. All that stored energy is from reactive power an only losses are active, but losses are mainly depend on current. As does flux density in the inductor, which can saturate. Thats about current limit. Also all load current goes trough inductor at any point of time. Both during on state(trough upper mosfet and inductor) and off state (trough lower mosfet and inductor). And during on state same current goes trough batteries and input capacitors (during off state batteries rest and charge input capacitors). So current stress on the input is same as at the output, but only during on phase, during off phase batteries rest. (there are also input capacitors but I asume they recharge much faster than entire off time)
@ The max switch current seen is actually only ~5.21A. Here’s the math: The average input current is 3.125A (output power of 5V × 50A = 250W divided by 80V input). The ripple current is calculated as ΔI = (Vin × D) / (L × F), where D = Vout/Vin = 0.0625, L = 10µH, F = 120kHz. This gives ΔI = 4.167A. The max current is the input current plus half the ripple: 3.125 + (4.167/2) = 5.21A. For the calculations, I’m assuming the frequency and inductance based on a what I’ve seen in other switch power supplies using a toroidal coil this size.
Dropping from 80V to 5tV at 17% duty roughly, will hit the switching tranny HARD! I expect they are cheap and well below specs for the "so called" specs of the unit. ...also for 1,000W, buck is not good topology, a transformer design is more appropriate.
Hi, so the fuse blew yes theoretical it was a 25amp fuse but if it was a Chinese fuse it could be wrongly rated (see Louis Rossman vid about amazon fuses). I don't exactly know what you are planning to do but if it is to run printers on 24V why not make the battery 48V (it is way more standaard than 72) and go with a victron DC DC so you go to 24V you know those are realable and won't explode.
I just happened to already have three of these Tesla batteries installed on my racks already. I'd prefer not to buy any additional ones to meet 2 banks of 48v considering these three are more than enough to run the farm. we're changing the layout and adding new printers. One thing to consider about the Victron, and most other manufacturers of inverter technology, they are most often for lead acid and LFP chemistry, they don't have the input voltage swing ability needed to utilize the entire capacity of lithium ion cells. Anyway, you can tell by how I explained my doubts at the beginning of the video; I did not have high hopes for this converter. But it made for an interesting experiment so other people can make informed decisions when purchasing such devices that can be a danger to sensitive equipment they connect to it.
Thanks for the comment! But, I thought in this day and age just about everyone who would watch a video like mine would know about ohms law before posting a comment like yours. Mate, 34 amps @ 5 volts on the output does not mean 34 amps on the input @ 80 volts... That would mean the converter uses 16 times more power to do the conversion than the load itself. That said, what did we learn? Either youve posted an erroneous comment, or you live on a planet where physics is broken. Either way, ease up, and have a great day! (no all-caps clown talk needed here, were all friends)
You are 100% right. This cheap converter wouldnt be a long term solution anyway as I am developing my own converter using the most ideal Texas Instruments driver money can buy. But I was hoping to buy some time and not spend a fortune to get things moving. Minimal down time for my printers is also a factor. Meanwell is a solid manufacturer. I have 9 rsp-3000 supplies running my farm since 2019 and they are still going strong today! As soon as they make a dc-dc converter with a mosfet rectifier topology that can achieve the efficiency rating of the TI device, Id go all in!
Hey thanks for your sub. Yes, I meant synchronous converter. Over the years, I've talked quite a bit about synchronous half bridge and full bridge converters and have found it to be more universally understood when I explain it in terms of using a transistor as the rectifier instead of a diode to maximize efficiency. This project will be based around the LM5116 synchronous buck controller from Texas instruments, and the LM5069 power good eFuse controller for an extra layer of protection.
This is an Aliexpress type PS of China. That's why the price is low. Never expect those systems to meet the max value. 1000W ? Nope may 100 to 500W max.
Upon further inspection, I discovered they used a single IRFz44 or similar transistor for the switch. Its rated for 50 amps max in this package but its not the simple when you're using it as an inductive switch. Transient currents have not been accounted for!
You should have looked for the error on the board - thats what we would expect and wanted to see. I think the voltage difference from input to output was too high and its the amps that make components hot, not the voltage. Typical cheap china crap i would say...
How so? Explain? did you even watch the video? The converter ran for actually less than five minutes. It's rated 50 A and I only use 34 A before the fet shorted out. The only thing that kept this converter from going up in flames is an Automotive fuse.
@@leckiestein The fuse blew and you weren't even filming it, your thumbnail is fiction, nothing blew up your title is a lie. Anyway I added you to the list of don't recommend this channel so lie as much as you want I wont be bothered. Oh and yes I foolishly watch all the bullsh1t.
In electronics, us old-timers (40 years and up) say "a transistor blew" or "I blew up a transistor" it means the same thing; this is controlled bench testing, not a blockbuster film :) If you want more excitement, try searching "lipo battery fire". Have a great day! :)
Hi Zoey, thank you for reaching out! If you wouldn't sending me an email, I have several projects coming up that will require a PCB to be manufactured. Looking forward to hearing from you. leckiestein@gmail.com - Chris
I am surprised that the ATO fuse was able to interrupt 80 V. They are normally rated for 32 V
Thats why it was extra charred:)
You bet! 80 volts can make quite the arc!
You'll want to use a 10x38mm PV fuse there. Auto blade fuses are a fire hazard at those voltages.
10x38mm PV fuses are ceramic fuses with, roughly 1000VDC ratings and very high interrupt ratings (40kA+). Usually sold in increments up to 30A or so.
Thanks for the comment! Lots of you guys mentioned automotive fuse is a no no - absolutely right. This is just what I had kicking around my home office. I have lots of WGPV-30 fuses at work that I will use for the final install. Realistically, i should have made the trip to get them for this test. Next time 🤞
@@leckiestein Yes, those are excellent fuses. 1000VDC, 33kA, 10x38mm ceramic PV fuses. Also look into DIN-rail mounted fuse holders to help organize the bits and pieces. Size fuses to 150% of your maximum expected continuous current to avoid overheating them, and within the cable spec.
Also check the fusing on the Tesla battery pack. When you are ready to tie it in, you might need a T-Class (200kA) first-stage fuse given the amount of energy it packs. The pack might already have one built-in somewhere but since you are likely using the modules individually you are probably bypassing it. So you'll need a T-Class (200kA) main battery pack fuse before you tie it into a bus.
Victron now makes busses with T-Class holders built-in that are very convenient for something like this. Victron Lynx Class-T Power-In with M10 bolts. Not cheap but probably necessary.
-Matt
Fun experiment! Thanks for sharing. Yeah you always have to take the chineseum ratings and convert them back to real ratings. Monitoring hotspots (surfaces of mosfets, etc.) and setting limits or improving the cooling as needed. You probably would have had a better chance at success if you went with the 24v output. 5v at 50A from 90v is an extreme conversion and would require double or triple the inductance or capacitance than it probably currently has. I had done a different test with a bit higher quality buck converter. I tested the output current with 24v in and a short on the output. It was surprising that the capacitors were getting really hot and not the mosfets. Certainly interesting stuff indeed.
I bought a couple of these but haven't used them besides basic testing. Unrelated to your test but interesting: They are synchronous buck converters so if you back feed on the output, it boosts the voltage back to the input but it doesn't have input over voltage feedback so it goes max voltage until the input caps blow. But we can use the icharger or others that have a recycle feature so when discharging a lipo, you can send the power back to a higher voltage big battery bank.
That little guy obviously has no ability to sustain 50A of output. Good call on the fuse. The power supply shorted out.... the FET probably died. Generally speaking when diodes and FETs die, they die into a crowbarred state.
You can't use a regular vehicle blade fuse to protect an 80VDC source. That fuse could easily have failed and turned into an ARC fire.
You can get proper power supplies with output over-voltage protection but if you are looking for something with a wide range of input that's a bit of a different kettle of fish. My solution for random high voltage DC inputs is to actually use a solar charge controller and a small LiFePO4 buffer battery. Fuse/breaker, charge controller, battery. I use the charge controller to trickle-charge the battery and the battery provides us with some bus protection as well as the ability to sink a lot of current at the lower voltage (just not continuously 24x7 since it is being trickle-charged).
An example of this would be, say, a 10x38 ceramic "solar" fuse (these are high voltage / high IR fuses), A Victron SmartSolar 150/35 charge controller, and a small (12, 24, 48V as you need) LiFePO4 battery with the current capabilities you need for the equipment. In this situation, the charge controller would be able to charge at 35A. So 12VDC output x 35A = 420W, or 24VDC output x 35A = 840W, or 48VDC output x 35A = 1680W. Something like that.
Voltages will actually be a bit higher to properly charge and float the battery. A 25.6V LiFePO4 batteries is charged to 28.4V and floated at 26.8V. Plenty good enough for 24V gear. For example.
And you get a ton of proper safeties with a real charge controller or DC-DC instead of the fly-by-night amazon model which has zero safeties. Note that charge controllers do NOT have well regulated outputs, hence the need for the battery is mandatory. A Victron (or similar) DC-DC would have a well regulated output without a battery, but has a more limited input voltage range.
p.s. does that power supply even have an input fuse of its own? It should have one on the board somewhere. If it doesn't it's a fire hazard that wouldn't pass any certifications (whether it lists any or not).
Or the fuse blew and it was fine.
@@evan010101 It is most definitely not fine. There is no such thing as a 'temporary' internal short in a MOSFET or diode.
In my QA & repair job at a tech firm 20-30 years ago, we used Cosel power supplies . Never really looked inside one, because THEY NEVER MALFUNCTIONED. Those were the days
No kidding, and just think of how inefficient they used to be with bipolar transistors and not the advance ultra low resistance fets we have today!
@@leckiestein I don't know how they get away with it? I had a bunch of voltage controllers from China about 10 years ago, ALL of them broke down well within HALF the ratings. I wince every time I see these solar folk and other project makers use these dangerous at times garbage things! There must be a lot of editing out of the woes of these units constantly failing. I thought you did well with your one here though lol, 70% surprised me :)
Hello, you wrote the use a Single IRDZ44 as the Switcher, On Pictures on the Web I see there are 2 Mosfets used , this seems to be a Synchronous Design made by a TL494 using it in the Single Output Configuration + an Half bridge Mosfet Driver that Drives the Low and Hi Mosfets, can you please check if from the 8pin chip there is a Path to the Gates of the Mosfets (through the Smd Transistors) ? Thankyou, Konstantin
Oh interesting! Maybe you can send me a link to the photos you're looking at? My converter is plastered with silicone and I'm sending this back to get a refund so I don't want to damage it trying to pry it up; I didn't actually pop off the heat sink to confirm the device it's likely the part number is etched off anyways, but I'm confident the transistor used would be no more than what a Z44 can handle because there's only two devices under that sink using what looks to be a TOLL package. They would have to be rated for at least 120 V and I don't think you're going to find anything at that voltage much more than 50 A in a TOLL package. Z44 is the first part number that came to mind but now that I think about it I believe that transistor is only rated for 60 V. Anyway, interesting that you mention it's a synchronous converter, I do see two traces and there's two transistors leaving the driver heading under the heat sink and I was wondering what the secondary trace was. If this is a synchronous converter that trace and extra transistor makes sense but that would mean the driver couldnt be a TL494 in that case. In order to use a TL494, you would have to use a gate driver such as a UCC27211 to handle the high and low side mosfets. I 100% don't have that on this board. So the big question is: what that heck is this Driver?!
Hi, the Photos are from Aliexpress where the Bottom side of the PCB is shown and there the Pins of are 2 through-hole Mosfets can be seen (just see the Botm of your PCB :-), either TO220 or TO247 donno. The SOIC8 Chip in my opinion a HalfBridge Mosfet Driver with integrated Dead-time like the IRS2184(but probably a CN Clone of it, I use these clones too) and not an opamp. The TL494 has already 2 Error Amplifiers integrated an one can be used for OCP. Btw., what is a TOLL Package ? Mosfets can be for ex. IR IRFP90N20D 200V 94A or HOOYI HY1920P 200V 90A or probably some CN part with similar data, the IRFZ44 is ancient and way underrated :-) A Similar Circuit CN DCDC Converter I have (just mechanical different and upto 75Vin and only 25A out) uses 2 HUAYI HYG043N10NS2P 100V 164A.
I don't know if this applies, but I fried a similar "400w" boost converter going from ~12V to 14.5V at around 7 amps. It fried as I was connecting/disconnecting the load after a few seconds of test - I think there was a feedback thing happening.
I added an 18V "TVS" diode to the output, so if I do get a spike, it would get dissipated instead of frying something.
After that modification, I didn't run into any more issues - its' been working great ever since.
In my experience what they do is quote a power but that power is at the least conversion so the highest output voltage so if it was a max of 60v output then the max current would be around 16A which would give a max output at 5v of 80W. I think it's deceptive to give a power rating on a variable output device as the limiting factor is always current. I know it's not quite that straight forward due to the PWM but I have many boost and buck converters and this current limitation always seems to hold true for the ones I have blown up. The same is true for MPPT converters which are quoted, more correctly, on output current and input watts s increase as the system output voltage increases so a 20A controller on a 24v system can handle twice the watts as it can on a 12v system.
Generally I've had a lot of luck, too, with buck boost converters meeting the ratings given. Usually once you get to the top end of the spectrum heat becomes the problem therefore duty cycle has to be limited. But in this case this unit is just completely improperly rated. The transistor used is only rated for 50amps. When you are switching at high speeds on an inductive load, transient currents can be three times this!
No. It might say this watt there or that watt there, but the specification literally says 50A on max output. You may then combine those 50A in anyway you see fit as long as you dont exceed max watt. As an example, 1000watt. So, if you want to charge a 500ah lifepo battery at 14,6v and 50A then you can do that. Except it blows, because they lied.
When I said switching high speeds on an inductive load I'm referring to the inductor used in the converter, not the final output. The initial circuit the transistor is connected to is a reactive circuit and they did not account for the transient currents that occur when switching at high speeds on a reactive circuit. The transistor should have been at least three times the rating. So yes, they grossly overrated this unit.
@@leckiestein I accept certainly that it is over rated. My comment was more observations about the ones I have seen. I do wonder if it might manage higher current with minimal reduction in voltage say with input at 60v and output at 55v although that would be too great with the transistor you say is used.
@@philbrooke-little7082 I can parallel 3 mosfets and that would likely do it. and you're right, if we can get the voltage difference to be smaller, the amount of energy needed to store in the inductor would be greatly reduced therefore increasing the reliability of the converter. However, the topology of this converter is problematic for sensitive work, if a transistor fails, it shorts the input rail to the output rail. Im making more videos on this topic as I carry out my work of fully battery backing up my entire print setup. Ive used the power designer tool from TI may times in the past to design power supplies so Im designing my own converters using a synchronous rectifier topology and this can achieve 99% efficiency.
My default assumption is to de-rate any questionable electronics I get off Amazon or Aliexpress to half of whatever they're advertised at, and potentially adjust downwards further based on thermals or component choices.
This is still pretty affordable for a 500W/25A converter, but it would be a lot nicer to not have to second-guess whatever numbers the manufacturer sticks on the product page.
Nice video, these amazon converters are often over-rated, I have had good luck with some by running characterization on them (primarily investigating stability with increasing load, feedback and output signals on the PWM controller) and using them well below their "rating" once that is understood. I have also had luck modifying feedback components or adding low ESR capacitors on input / output rails. Of course, that's a lot of time invested to work around the cheapness. One additional note, most blade fuses are rated for 32V, so they may not provide protection reliably in this scenario (80V,) when breaking higher voltages the fuse can sustain an arc or even plate out internally preventing it from interrupting.
Hey thanks for your comment! Making sure we stay safe out here. The Automotive fuse is just what I had laying around as this is just my home office. But at work, Ill be sure to use a littel or Bussmann High-Rupture Capacity fuse when doing the final wiring :)
If you need 24v and are using 3 * 24v packs ..... how about using the 3 packs in parallel?
Hi there! It comes down to what is most cost-effective. So the idea is to have a single server rack house 20kw worth of power supplies including a 72v battery. Each printer rack needs roughly 2.2kw for 12 printers and runs on 24 volts. The average distance to run wire from each print rack to the server rack is 50 feet. If you do the math: To deliver 2.2kw at 24 volts 50 feet away with min voltage drop, I would need 100 feet of cable, and nothing less than a 0 awg pure copper would deliver to the site with minimal voltage drop. I currently have 7 racks so that's about 700 feet of zero gauge wire needed. At $11.50 CAD per foot * 700, it would cost me $8000! If I run high voltage with a DC converter at the print rack, the wire can be 12 AWG which is $0.60 per foot and I will have exactly 24v at the rack with a converter since voltage drop won't be an issue as the converter can compensate for the difference in input voltage. Make sense?
How do the existing printer power supplies actually behave when fed with HV DC instead of AC?
Can you distribute the backup to be at the point of use?
AC's advantage is to be able to easily change voltage for lower amperage transmission. There exists a distance at which transmission in AC becomes cheaper. In this use case, you can use the cheaper "off grid" inverters since you are not feeding power back into the grid.
I have some meanwell supplies currently running my Print farm that can handle dc and ac input but im far out of the operating range. I believe the low and threshold is 160 VDC
@@leckiesteinI would use paralleled modules to run a 240V inverter (or 120 if you like) and distribute that, then use the printer’s PSUs as normal. Cheap and simple and safe.
If I wasn't planning to make videos of the engineering and building process, absolutely! But, Id like to grow my channel with unique content. Connecting batteries to inverters has been done to the 9's. I think people will be more interested to watch the experimental/development process while giving me the opportunity to utilize some expensive gear I already have and its a great practical learning experience for everyone :)
As soon as I saw you pushing the amps up I new it would fail I have some similar units and in the instructions they indicate the current at such wide voltages has to be reduced and they note a max current at the output which is about 30 amps and my units say 1500 watts they also have fuses installed.
5:15 use parallel Diode for each battery pack . it will be good to protect reverse voltage and forward the voltage when one of the batteries is in voltage cut-off stage.
Good idea, although normally the problem there is you need a big enough diode, it would work in this case because he only needs a 2A diode.
@@vgamesx1 You should also have an undervoltage shutdown at the downstream load so that if one battery disconnects, the load disconnects as well. If your load is a power converter, it will generate a massive current spike, as soon as one battery in a series connection drops out. Imagine drawing 1000W with 4x20V batteries and all of a sudden you only have 60V instead of 80V, but the load still draws 1000W. Current would shoot up from 12.5A to 16.7A. If you only have two batteries, the current would likely double. So the rectifier diode needs to be sized for the current to be expected at the lowest possible working voltage.
2:02 at the Top should be some fuses normaly i think...
But there Bridged xD looks more like a Shunt for 50A than a Fuse 😂😂😂
My assumption is that the "most false" part of the advertising are the 50A and not so much the 1000W (maybe this can deliver 500-750W with a higher output voltage like 40-50V).
Also I think the spike from the sudden change in the DC load was quite bad for this unit, as you said it does not even have ceramic capacitors so big spikes might occur when that expensive DC load changes its apparent resistance in microseconds each time you turn the dial 1 click. Maybe I am wrong, but I want to be totally fair with the unit.
Very instructive video. I will probably not purchase that unit, however, when "chinesium" is involved I usually tame my expectations to about 1/2 of the advertised specs. If not less.
Even if it is not ideal for me the usage of this fuses not rated for 80V is not as concerning as some comments say. Maybe for industrial usage it is, for a controlled environment, I do not expect them to arc like crazy at that voltage levels even with high temperature and so on. And it is better that than nothing.
Cheers.
Many switching power supplys can run on dc for example 110v dc so maybe you can add another battery to get around 100v dc and try few models of power supplys to see if they work on dc. Probably the original psu's of the printers can do it
Absolutely, and thanks for the comment. Back in 2019 when I started building my print farm, I did consider this so I purchased Meanwell rsp-3000 power supplies and they can do 165vdc - 270 I believe. Anyway, I have 9 of them running my printers right now. The plan was always to get a model Y battery back when they became more available and split the pack in half which would be 200 volts. This plan was formed before the recession. Now the 3 phase high voltage power supplies and the batteries would cost more than all of my printers put together which the majority of the farm is bambu A1 minis. These printers also require half the power of the original printers so all in all, I dont need as much battery as I once did with the ever-evolving 3d printer of today and Id like to use what I have to save that money to put towards more printers
@@leckiestein Yes, though remember that Mean Well is a premium OEM. Their supplies have more safeties than you have fingers and most are fully rated for both AC and DC inputs.
It all depends on the design. Cheap power supplies often have a transformer to reduce the AC voltage BEFORE going into the rectification stage and cannot handle a DC input (a DC input will just short-out the transformer). They do this so they can use cheaper low-voltage components.
Premium power supplies have high-voltage rectification and/or switching circuitry BEFORE the transformer. Particularly power supplies with PFC circuits. These can theoretically handle AC and DC inputs.
That is kind of what I am researchig about. I took a risk and powered a network equipment cabinet at 300VDC. There were ubiquiti, Mikrotik, TPlink routers and network switches in that cabinet. The equipment has worked flawlessly for almost 3 years now and still going.
@@collinsmwaura1833 The fuses and switches and any AC relays in that equipment can't handle DC ARCing though, especially at 300VDC. You've created a massive fire risk by doing that.
I do run small devices directly from LVDC in a few places that I need to backup. Like a network switch or cable modem. If their power bricks output 12VDC then I can just clip them out and run them from a fused 12VDC battery system, for example.
-Matt
That flashbang was probably due to the load dump when the DC load tripped.
Being too careful and you probably forgot the load was only capable of 30 amps..
All the same the components look more like 200 watt than 1000 watt capable.
Hmm. Curious where you got your 30 amp figure?
I'm confused... I can't understand why the fuse popped... You were draining about 2 amps from the battery, the fuse is 25A.... Why the hell it popped?
Do you means that the high power MOSFET shorted and caused an high current spike?
Anyway NEVER NEVER NEVER trust the specs about batteries and converters sold on Amazon or eBay or AliExpress... The Chinese manufacturers and seller are ALWAYS EXAGGERATING THE SPECS, like the power banks with a 5Ah battery advertised like a 20, or like you experienced , a 150W converter advertised like 1000w. I learned the lesson: always think that the real specs are about 10% of the advertised one...😂
Hey thanks for your comment. Ya, its crazy, there was only about a total of 3 amps worth of current running through the switch transistor before the fuse popped. A few things could have happened: the amount of flyback voltage on the transistor could have been too high causing the short because I really doubt there was too much current or the current on the rectifier was too high causing the rectifier to short. Either way, I had it replaced and Im going to give it another go under different conditions in a coming video!
Thanks again for sharing, I just came across Your channel and I think I´m gonna stay. Your setup is awsome, everything is right at hand… I consider myself a tinkerer, too but I am not half as sophisticated. My next goal would be to create some kind of voltage standard to check the accuracy of my gear,
But there´s a hen/egg problem: how do I check accuracy with "unknown" gear? I recently aqired a Metrawatt MA 5D meter, it can do all I need: volts/amps/resistance and capacitance. Now, the company is not interested in repair anymore but they want me to get new gear that I can´t afford.
So I go on the usual suspects sites to look for something I can. Now, I checked against known parts and the Metrawatt as my Voltcraft tell the same so I feel safe there. I want to get into tape decks & stuff where milivolts matter, now I think I can.
Have a good day Mate, You and Your loved ones be safe.
Hi @LaLaLand.Germany,
Thank you so much for your kind words and for taking the time to share your journey-your tinkering setup sounds impressive, and I’m thrilled to hear you’re enjoying my channel! Having a reliable voltage standard is such an interesting project, especially for fine work like tape decks where every millivolt counts. It sounds like you’re already off to a great start with the Metrawatt MA 5D and the steps you’ve taken to validate its accuracy.
I completely understand the challenge of finding affordable yet reliable equipment. That’s actually one of the reasons I enjoy diving into bench testing and sharing projects like these-making high-quality tools and knowledge accessible to everyone.
Speaking of projects, I’m excited to share that this channel is now sponsored by JLCPCB, which opens the door to some awesome upcoming builds! I’ll be designing and testing custom PCB projects that I think you’ll enjoy- lots of power supply projects and everything from innovative tools for tinkerers like us to creative ways to solve everyday challenges.
Thank you again for your support-it means the world to me. I’m looking forward to seeing you around the channel, and I hope you and your loved ones stay safe and well. Have a great day, Mate!
Cheers,
Leckiestein
When you are doing 'tests' totally out of specs of the parts/components, you can expect this kind of results and more.
Probably ablet to do a peak of 15 Amps at 80 volts or such. But really a peak like for half a second with a low duty-cycle like once in an hour and normal load max 5 amps output.
But with 5 V. out, probably max. 25 W for a bt longer time with an input of 30 Volt.
If you cannot find the specs of the total design, the components and tracks will give you lots of clues.
For your way of fusing.... to protect the batteries and cables, better use something that can handle this voltage to cut.
Also, add fuses and some kind of smoothing on the input . If you had put an oscilloscope at the input, you would probably have seen sad loads and voltage-drops too due to the high voltage-differences you had during the short test. Actually, the peak currents through the battery-packs might induce problems on the protection-circuits inside the battery-packs very fast too. They are designed for much more constant DC-loads then the high-frequency load you have put through them. Using packs like these straight on the input of an inverter can also ruin the converter.
Converters like these can probably work much better on normal lead-batteries.
Just imagine the high currents during the small peaks on the inside of the converter with 1% or such on 10Khz for example.
As you got that error message from your load, that it was going to disconnect, it seems that the sudden loss of load is what destroyed that cheap converter.
This seems to be a design flaw with your load, it should have not disconnected, but instead just limited how much it was drawing. Many switch mode supplies have a minimal load spec, and suddenly going from heaps to zero at a ridiculous speed (like opening relay contacts) can kill even the best of them.
The electronic load disconnected because the converter switching transistor shorted thus the input was shorted to the output. The electronic load suddenly received 80 some odd volts while trying to pull 34 amps. 80*34= 2720watts. The electronic load is only rated to do 350 watts max.
Listed rating on internet shop? Apply safety coefficient of 0.2 on what is listed, then you get real value. They remove those markings on smd, not to prevent cloning of device, they do it to prevent claims and reclamations that people will recognize immediately device is not within spec. Then you turn it on, burn it maybe and thats it no reclamation.
I would never use my nice rigol test load for testing these sort of cheap supplies
I would be lying if I said that thought hadn't crossed my mind 😂
Good effort. I didn't like the look of the PCB converter: small caps, copper winding. What a variable power supply with a fan?
💥💫
The way i understand the exaggerated/misleading "1000W" is as the area of the operating envelope: (Vin-Vout)*Iout. 75v*20A = 1500W; 50% more than rated. OTOH, with that size heatsink and fan, I'd guess it was good for about 50W dissipation. If we call it 95% efficient, then about 13A would be the max (48.75W) for 75v/5v, and as it so happens, that correlates with ~1000W.
You need a 24v (adj,) meanwell 1500w PSU? I got it to build an RC charging case and never built it. Cheap!
Hey! What's the model number, Ill have a look! Im actually in the market for something to charge the batteries on my enclosed solar trailer (coming in a future video).
@leckiestein RSP 1500-24
@@leckiestein @leckiestein RSP 1500-24 - I noticed you're a CA resident. That would make the exchange difficult imo; but if you're still interested, lemme know. I thought of running all of my 24V 3d printers off one PSU. I imagined the cost of the 8awg fine strand wire going to each machine (2 Voron and 1 Creality) would be too pricey. It would be worth it in a 3d printing farm, maybe.
You shouldn't have dropped that much voltage across converter.you should have set output at 24v and tried to load at that first.5v was just to low🙂
You would be right! Were trying to store so munch energy in the inductor. My thoughts on doing this was to run an initial test before wiring it to my expensive electronic load in series with a battery. I received a replacement converter so keep an eye out for the video - ill be testing at 24 volts.
@leckiestein awesome! I've looked into these converters specs in detail.while they are a bunch of junk to me anyway,lol,I'm gonna give one a go to see if it will power my new solid state high voltage multiplier sometime next year.i need 3 to 18vdc at 35 amps.i love linear supplies but there's too much power dropped across them, when u drop the output voltage.worst case is the converter will smoke and I'll have build a fifty pound linear supply that won't turn down as low.anyway great video.id set the input at 60v roughly and sit 20 to 30v on output.put 20 amp load and cross your fingers.hope for best,plan for worst.lol.ill look for your video!!best wishes.
why not just run the battery packs in parallel? no conversion losses. and you'll have the amperage from 3 of those packs available.
i dont understand why you take 24 volt packs and rig up some circuit and module to put out 24 volts.
Hi there! It comes down to what is most cost-effective. So the idea is to have a single server rack house 20kw worth of power supplies including a 72v battery. Each printer rack needs roughly 2.2kw for 12 printers and runs on 24 volts. The average distance to run wire from each print rack to the server rack is 50 feet. If you do the math: To deliver 2.2kw at 24 volts 50 feet away with min voltage drop, I would need 100 feet of cable, and nothing less than a 0 awg pure copper would deliver to the site with minimal voltage drop. I currently have 7 racks so that's about 700 feet of zero gauge wire needed. At $11.50 CAD per foot * 700, it would cost me $8000! If I run high voltage with a DC converter at the print rack, the wire can be 12 AWG which is $0.60 per foot and I will have exactly 24v at the rack with a converter since voltage drop won't be an issue as the converter can compensate for the difference in input voltage. Make sense?
But is this practical, who needs 5V at 30A. That would really charge your phone to oblivian. You also overloaded the voltage right.
I built a display in a showroom using addressable LEDs; the entire display is about 150 A at 5 V. if there was a situation where someone wanted to run addressable LEDs from a lipo battery, this would be a good option (if it doesn't short out first lol)
You used the wrong watts, we found many years ago that far eastern 'seller watts' are approx 1/3 of a 'standard electrical unit watt'. after lots of testing and measuring that conversion factor from 2006 still seems accurate to this day......
This unit was a let down, i expected it to smoke about 400w going on a guess from its physical size.
Its maybe been fitted with a cheaper mosfet in the chopper stage. it may be worth fitting a new 100v rated one in at as many amps as you can get in the package size to fit the original pcb, you may find then it actually is a moderate board.
Once I bought an inverter that had a bad fan, it smoked, returned for replacement that did its 2000w, but smoked after its 3rd morning coffee brewing in the camper, they refunded and said dump it, i took the refund and replaced all the fets with decent ones, ones in it were 500v 30a as they should have been but a different part number by 2 letters from the pcb, different manufacturer and while the amps/volts matched, the package total watts didnt (250 not 395), i guess they substituted on volts/amps onlly and not watts, and guess they will have got many returns for a design that was good if they built it to spec. its 7yr old now...
I think what you are talking about is RMS and peak power. RMS is about 0.707*peak power
@@leckiestein No, no i'm not lol..... far eastern seller watts run about as true as far eastern seller mah's on rechargeable batteries....
you cant even buy a 10w led bulb that runs at 10w from any of the big online sales buckets...... anything bought on banggood, ali, amazon affiliate seller, ebay, you cant trust it, you may as well be buying from temu or wish.
One thing learned over the years, buy on footprint area, buy on mosfet count, buy on weight, dont buy on published seller claims....
only good thing about that mystery box is the tl chip in it, at least thats maybe ok and so replacingg the mosfet's or output diodes is maybe possible, to make that 1000w supply ok. (well 300 real watts in that footprint)
TLDR choke smps arent wattage limited but rather cureent limited and voltage limited, and current cannot rise inside choke, so if you want 50 amps at output then it needs those 50 amps at input at lower duty cycle, thats why high power buck converters REQUIRE very good input capacitors. So obviously you cant get 1000w at 5 volts from this humble unit - even inductor is probably going to saturate despite being black kool mu - it has way to many turns for 200 amps. For real power you need special stuff like whats used for CPU/GPU: high frequency to have small inductor with less turns and thicker wire, multiphase if difference in voltages is too big (since its directly affects duty cycle which you cant make too small without sacrificing efficiency) and so on.
For that thing I expect current limit to be about 20-25 amps and it could in theory handle it well.
@leckiestein thats not how buck converter works, if you want 50 amps at output then you need 50 amps choke current. Voltage difference is t_on/t_off. So even with 100% efficiency you draw 50a*80v for 1/16 of period, then release 50a*5v for 15/16 of period.
Assuming 100% efficiency, to pull 50 amps @ 5 volts on the output, we would only need 3.1 amps on the input at @80 volts. Ohms law.
@@TURBOSLAYERPWNZ Please know the difference between passive and reactive circuits. Whatever POWER (not current aka amps) comes into the converter, it will be the same power that comes out of the converter minus any losses that happen during the conversion process aka resistance in the inductor, switching mosfet, rectifier, board traces, etc., that create heat.
@@leckiestein It seems that we are talking about different stuff. You are talking about what comes in and out of converter on AVERAGE, while I am talking about what happens inside and stresses its components at different moments. Converter has parts that store energy - inductor and capacitors. All that stored energy is from reactive power an only losses are active, but losses are mainly depend on current. As does flux density in the inductor, which can saturate. Thats about current limit. Also all load current goes trough inductor at any point of time. Both during on state(trough upper mosfet and inductor) and off state (trough lower mosfet and inductor). And during on state same current goes trough batteries and input capacitors (during off state batteries rest and charge input capacitors). So current stress on the input is same as at the output, but only during on phase, during off phase batteries rest. (there are also input capacitors but I asume they recharge much faster than entire off time)
@ The max switch current seen is actually only ~5.21A. Here’s the math: The average input current is 3.125A (output power of 5V × 50A = 250W divided by 80V input). The ripple current is calculated as ΔI = (Vin × D) / (L × F), where D = Vout/Vin = 0.0625, L = 10µH, F = 120kHz. This gives ΔI = 4.167A. The max current is the input current plus half the ripple: 3.125 + (4.167/2) = 5.21A. For the calculations, I’m assuming the frequency and inductance based on a what I’ve seen in other switch power supplies using a toroidal coil this size.
Dropping from 80V to 5tV at 17% duty roughly, will hit the switching tranny HARD!
I expect they are cheap and well below specs for the "so called" specs of the unit.
...also for 1,000W, buck is not good topology, a transformer design is more appropriate.
Hi, so the fuse blew yes theoretical it was a 25amp fuse but if it was a Chinese fuse it could be wrongly rated (see Louis Rossman vid about amazon fuses). I don't exactly know what you are planning to do but if it is to run printers on 24V why not make the battery 48V (it is way more standaard than 72) and go with a victron DC DC so you go to 24V you know those are realable and won't explode.
I just happened to already have three of these Tesla batteries installed on my racks already. I'd prefer not to buy any additional ones to meet 2 banks of 48v considering these three are more than enough to run the farm. we're changing the layout and adding new printers. One thing to consider about the Victron, and most other manufacturers of inverter technology, they are most often for lead acid and LFP chemistry, they don't have the input voltage swing ability needed to utilize the entire capacity of lithium ion cells. Anyway, you can tell by how I explained my doubts at the beginning of the video; I did not have high hopes for this converter. But it made for an interesting experiment so other people can make informed decisions when purchasing such devices that can be a danger to sensitive equipment they connect to it.
*YES A "CLOWN" 20 AMP FUSE .... THEN PULL 33 AMP .... !!!*
*EVERY IDIOT KNOW THE FUSE **#BLOW** .*
(IT MUST)
*IS NOT A "REGULATOR" FAIL ....*
Thanks for the comment! But, I thought in this day and age just about everyone who would watch a video like mine would know about ohms law before posting a comment like yours. Mate, 34 amps @ 5 volts on the output does not mean 34 amps on the input @ 80 volts... That would mean the converter uses 16 times more power to do the conversion than the load itself. That said, what did we learn? Either youve posted an erroneous comment, or you live on a planet where physics is broken. Either way, ease up, and have a great day! (no all-caps clown talk needed here, were all friends)
So far i wouldn't even bother with this kind of DC-Dc converter.. I would go for MeanWell brand they are pretty ok
You are 100% right. This cheap converter wouldnt be a long term solution anyway as I am developing my own converter using the most ideal Texas Instruments driver money can buy. But I was hoping to buy some time and not spend a fortune to get things moving. Minimal down time for my printers is also a factor. Meanwell is a solid manufacturer. I have 9 rsp-3000 supplies running my farm since 2019 and they are still going strong today! As soon as they make a dc-dc converter with a mosfet rectifier topology that can achieve the efficiency rating of the TI device, Id go all in!
@@leckiestein "mosfet rectifier topology"? Do you mean synchronous converter? Anyway, I would like to see your own converter development! Subscribed
Hey thanks for your sub. Yes, I meant synchronous converter. Over the years, I've talked quite a bit about synchronous half bridge and full bridge converters and have found it to be more universally understood when I explain it in terms of using a transistor as the rectifier instead of a diode to maximize efficiency. This project will be based around the LM5116 synchronous buck controller from Texas instruments, and the LM5069 power good eFuse controller for an extra layer of protection.
obviously it wouldn’t 😂 u know this 😂
No doubt! Ha! But it would be a pretty boring channel if I didn't try to push these things to the limit lol
This is an Aliexpress type PS of China. That's why the price is low. Never expect those systems to meet the max value. 1000W ? Nope may 100 to 500W max.
Upon further inspection, I discovered they used a single IRFz44 or similar transistor for the switch. Its rated for 50 amps max in this package but its not the simple when you're using it as an inductive switch. Transient currents have not been accounted for!
tip of an iceberg of all the fake wattage listed converters on ebay and amazon buck and boost. sadly they like adding fake zeroo000000000s
Just found your channel buddy, love the things your doing, subbed, rung the bell, and a thumbs up buddy 😊😊😊
Right on man! Happy to have you here!
Likely an extra 0 in the listing.
50. Amps. I doubt it
You'get 1,000% more success putting three 24V cells in parallel, giving you the opportunity to learn what cell balancing is all about.
You should have looked for the error on the board - thats what we would expect and wanted to see. I think the voltage difference from input to output was too high and its the amps that make components hot, not the voltage. Typical cheap china crap i would say...
the fuse made this video boring :(
👎 for clickbait thumbnail and a lying title, joke channel.
How so? Explain? did you even watch the video? The converter ran for actually less than five minutes. It's rated 50 A and I only use 34 A before the fet shorted out. The only thing that kept this converter from going up in flames is an Automotive fuse.
@@leckiestein The fuse blew and you weren't even filming it, your thumbnail is fiction, nothing blew up your title is a lie. Anyway I added you to the list of don't recommend this channel so lie as much as you want I wont be bothered. Oh and yes I foolishly watch all the bullsh1t.
In electronics, us old-timers (40 years and up) say "a transistor blew" or "I blew up a transistor" it means the same thing; this is controlled bench testing, not a blockbuster film :) If you want more excitement, try searching "lipo battery fire". Have a great day! :)
@@leckiestein Well thanks for the effort you put into the reply, entirely irrelevant but well done for trying to make sense, maybe next time eh.
No worries mate. Thanks for the feedback - ill keep it in mind for future posts.
Interesting test. If any custom PCB may help for upcoming work? We're open to sponsor and see how it turned out. (PCBWay zoey)
Hi Zoey, thank you for reaching out! If you wouldn't sending me an email, I have several projects coming up that will require a PCB to be manufactured. Looking forward to hearing from you. leckiestein@gmail.com - Chris