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.
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 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.
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.
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.
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
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 :)
...💭 well maybe just my opinion: It's just a circuit, meaning it's working in both directions... Adding a diode for blocking on the output side to prevent the current from flowing back to the input side or having a ground connection on the housing is necessary for propper operation which likely is meant to be @32Amps @ the rated 50Amps according to the general roules for specifications. Don't forget these kind of products are just meant to be used for shorten development times of new appliances 😮 And regarding that just the fuse has blown it might be still working ❓‼️ Thanks for sharing your experience with this experiment!
Hey thanks for your comment. The topology used in this converter would never allow for voltage on the output rail to flow backwards to the input UNLESS something has gone wrong like it did here when the switching transistor shorted thus bridging the input and output rails together. Upon further inspection of the switching device used, it was a single IRFZ44, and this is the problem. They over rated the converter! That transistor's max rating is 50 amps to a resistive load. When switching on an inductive load, it should be about 3 times higher to compensate for the transient current of the inductor to meet the 50amp rating they gave this converter.
@leckiestein ...if I'm not completely wrong the ratings are always meant to be to a resistive load? and for operation this has to be devided by 1.6, sometimes deviding by √2 is okay, and then the required safety factor has to "added" ...e.g. 1.5mm² Cu can take 23Amps. that's the rating 23:√2:min. Saftyfaktor1.5 ==> 23A :(√2*1.5) = 23A*0.47...well in Asia the min. safetyfactor = 1.25 if I'm not wrong ==> Rating*0.566 that should be good for 50min. and like in this case on Resistive loads ... The unanswered remaining Question is the Rating or is the IRZ Rating already with the Asian Safetyfactor or without... Regarding the "price pressure" (Asset management...) very likely without and if no safety is required you end up with 1:1.6 or 1:√2 for resistive loads according to the Rating which also is the Rating of international rectifiers... Components for developing... Cheers...
I'm talking about the characteristics of the transistor that was used, the rating is 50 A max. The manufacturer of the converter use the transistor rating as their converter rating which is incorrect because the converter uses an inductor; that's the coil that you see in the centre of the circuit board. The transistor switches the power on and off very quickly into the inductor and the inductor stores some of that energy therefore giving us the ability to create a voltage difference between the input and the output but the power should be relatively the same minus any losses due to inefficiencies which create heat. The load in the test is a resistance load, but the transistor doing the switch is connected to an inductor which is then rectified with a diode and filtered with the capacitors on the output rail. This is called a reactive circuit and some funny things happen in reactive circuits that have to be accounted for when choosing the correct semiconductors; which they were not when they rated this unit.
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...
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
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.
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
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!
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.
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 an IRFz44 transistor for the switch. Its rated for 50 amps but its not the simple when you're using it as an inductive switch. Transient currents have not been accounted for!
![ร้อยพ่อพันแม่ - WanMai [Official MV]](http://i.ytimg.com/vi/XY2pNYASEbg/mqdefault.jpg)
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.
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 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.
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.
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.
Good effort. I didn't like the look of the PCB converter: small caps, copper winding. What a variable power supply with a fan?
💥💫
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
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 :)
...💭 well maybe just my opinion:
It's just a circuit, meaning it's working in both directions...
Adding a diode for blocking on the output side to prevent the current from flowing back to the input side or having a ground connection on the housing is necessary for propper operation which likely is meant to be @32Amps @ the rated 50Amps according to the general roules for specifications.
Don't forget these kind of products are just meant to be used for shorten development times of new appliances 😮
And regarding that just the fuse has blown it might be still working ❓‼️
Thanks for sharing your experience with this experiment!
Hey thanks for your comment. The topology used in this converter would never allow for voltage on the output rail to flow backwards to the input UNLESS something has gone wrong like it did here when the switching transistor shorted thus bridging the input and output rails together. Upon further inspection of the switching device used, it was a single IRFZ44, and this is the problem. They over rated the converter! That transistor's max rating is 50 amps to a resistive load. When switching on an inductive load, it should be about 3 times higher to compensate for the transient current of the inductor to meet the 50amp rating they gave this converter.
@@leckiesteinwait, i thought you were using a resistive load? Or did i just misunderstand everything 😅
@leckiestein ...if I'm not completely wrong the ratings are always meant to be to a resistive load? and for operation this has to be devided by 1.6, sometimes deviding by √2 is okay, and then the required safety factor has to "added"
...e.g. 1.5mm² Cu can take 23Amps. that's the rating
23:√2:min. Saftyfaktor1.5 ==> 23A :(√2*1.5) = 23A*0.47...well in Asia the min. safetyfactor = 1.25 if I'm not wrong
==> Rating*0.566 that should be good for
50min. and like in this case on Resistive loads ... The unanswered remaining Question is the Rating or is the IRZ Rating already with the Asian Safetyfactor or without... Regarding the "price pressure" (Asset management...) very likely without and if no safety is required you end up with 1:1.6 or 1:√2 for resistive loads according to the Rating which also is the Rating of international rectifiers... Components for developing...
Cheers...
@@MegaCyrik ...the remaining Question is why did it failed already at 33Amps there's still a difference of 2Amps?
Measurements?
I'm talking about the characteristics of the transistor that was used, the rating is 50 A max. The manufacturer of the converter use the transistor rating as their converter rating which is incorrect because the converter uses an inductor; that's the coil that you see in the centre of the circuit board. The transistor switches the power on and off very quickly into the inductor and the inductor stores some of that energy therefore giving us the ability to create a voltage difference between the input and the output but the power should be relatively the same minus any losses due to inefficiencies which create heat. The load in the test is a resistance load, but the transistor doing the switch is connected to an inductor which is then rectified with a diode and filtered with the capacitors on the output rail. This is called a reactive circuit and some funny things happen in reactive circuits that have to be accounted for when choosing the correct semiconductors; which they were not when they rated this unit.
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
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
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.
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
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
I would never use my nice rigol test load for testing these sort of cheap supplies
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 ....*
obviously it wouldn’t 😂 u know this 😂
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 an IRFz44 transistor for the switch. Its rated for 50 amps but its not the simple when you're using it as an inductive switch. Transient currents have not been accounted for!