The Ultimate Buck Converter? - Juntek DPM8650
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- Опубліковано 1 лип 2023
- Up to 75V input voltage, up to 60V output.
50A maximum output current.
7-segment displays for voltage and current.
And a wireless remote controller with LCD display.
www.aliexpress.com/item/10050... - Наука та технологія
That´s a very good converter indeed.
Would be interesting to have a look at the output voltage ripple, if you have the setup.
It's so easy to assume the display tells it all, like it's the clean output of a battery pack...
The banana plug connections are pretty slick!!
Thanks :)
Thank you for the introduction Julian. Can't wait for the disassembly!
Wow.....that's a wonderful thing. I love the Juntek gear and have been using their 80v 5A models for a couple of years now. They are very reliable. Thanks for the show.
The ultimate buck converter is the electronics hobby itself. It does an amazing job of converting your bucks into clutter and smoke.
WOW! I can say that is a really nice unit! Can't wait for the teardown to know for sure!
I got the WD4050 which was about 1/3 the price, but if you have the budget that certainly is a Cadillac of buck converters!
Ultimate buck ? Depends on the price.
Looks pretty good to me
Nice to see a Chinese product with Rising Clamp connectors. This is definitely an step up from the usual rubbish.
I might get one of these to play with myself. It looks to be higher quality than the usual chineseum on the domestic market.
Can't wait to see the teardown and how its made inside! Also want to see a real heavy load test with 60V and 50A - 3000 W of power from this device - we will see how it ends 😏
It is beefy and impressive, but RD tech has made a name for themselves as a Chinese brand you can trust to make quality products, so personally unless it's cheap I wouldn't buy from anyone else at this point.
Juntek has been making this model for about as long as RD Tech has been around and they focus on high-output models that Rui Deng doesn't make, so get the right tool for the job. I like RD Tech, but Juntek is an established and proven brand. I'd buy a Rui Deng for my bench and a Juntek for high-power applications.
Both are budget brands, but RD Tech has developed new and improved models while Juntek seems to keep selling the same buck converters year after year (no boost models that I'm aware of). Juntek doesn't seem to promote their products very well, either, as they're hard to find and that's probably why Julian hasn't tried one before ;).
Bhi
I recall seeing these a couple years ago but they were a little pricey and i didn't need anything that big but i remembered some that were smaller to but i also remember a control panel that was separate with more info i think it was wireless but it might have been wired
pity it doesn't also do boost. it would make it far more useful.
Exactly what I was thinking. A bigger brother to the 7210A.
Yes, but it also gets more inefficient. You loose quite a bit of conversion efficiency with buck/boost combined!
The LTC3780 is a sychronous buck/boost. Also I'll be trying the LT8705 buck/boost soon :)
Hi Julian,
I have the Juntek DPM8624-RF.
With this device I wanted to charge batteries. It said in the description this is possible. I came to the conclusion it's INCREDIBLY DANGEROUS to do that with this device, because during powering on, the device will short the plus and minus on the load side. Also when the device is powered off I believe the plus and minus are shorted.
I had a very bad short circuit once, and had smoke everywhere.
Could you test this device if you are also experiencing the same?
was thinking this would be good to remotely monitor whats going on in a caravan. we seem to have so many issues and would be handy to see what the voltage and currents are at the battery but not if it shorts it
Could that be the "fast discharge" system. I've watched it rapidly discharge the output capacitors when the output is switched off. The manual says it also does it when the output voltage is being reduced. On the DPM8650 the fast discharge mechanism can be disabled. I'll look at this more in my teardown.
@@JulianIlett That could be it indeed. I have not checked for this function as far as I can remember. Looking forward to your teardown
That could be really handy in a camper van with leasure / agricultural battery's.
Likely R/T for TTL serial, A/B for RS485 with modbus available on both. Hopefully they can provide the register map.
I think fast discharge mode limits or loads the output to avoid current dumping from output capacitance or bypasses some of the available o/p capacitance.
I have a DPM8624-485 (afaik there is a TTL version without the 485 at the end and the Modbus/RS-485 versions have that extension).
Had no time to try it yet especially since I am still waiting for a power supply, but my plan was to use it for battery charging where a microcontroller would control the charge process via modbus. Apparently there are Arduino libraries for it.
Did you ever get this working with MODBUS?
@@VonBugle Sorry for the late answer. Haven't got it working yet, because of a grounding issue I fried the RS-485 adapter that came with the unit.
For anyone reading this I recommend getting a proper RS-485 adapter that has ground broken out (RS-485 needs ground) and ideally also isolated. The cheap adapter that is supplied with the unit has no ground connection and relies on the external grounding over the USB Port and since it isn't isolated (at least mine wasn't) it's easy to kill.
@@Ether_Void hi I have a question are you successfully control the voltage setting and current setting using microcontroller?
Bana plugs are a good idea, so long as you stay within their current rating of about 15A.
Great tool and review! It reminds me of the Rui Deng Buck Converter like the DPM5020 or the new DPM6024 with up to 24 Amps. 50 Amps really is a word and i would like to see a heavy load test on the Juntek - so you need a 50 Amp load. Can it really handle 60V at 50 Amps? Thats 3 kW power in this little plastic device? Also interesting: what about conversion efficiency, ripple output, min. voltage drop. I would have loved it more to have the multicolor display on the converter directly rather than having a remote control.
This 25amp version has a claimed power capacity of 3000 Watts, which sounds like a lot of bang for the buck provided that the buck does not go bang 💥. Would you say that this buck converter would be practical for stepping down the voltage from PV panels to charge a battery? 🤔
Two things to watch: The slow rise of current from the solar panel may cause the buck converter to oscillate or even crash. Putting a battery on the output of a buck converter will back feed current to the input. Of course, the 2nd issue might solve the 1st issue.
Note that a standard MPPT solar charge controller does Maximum Power Point Tracking - it optimizes the power produced by the solar panel by operating (tracking) at the most efficient voltage on the panel for the current conditions. This buck converter will not do MPPT.
I don't think that this device does MPPT, which you'd want for solar.
I have the Rui Deng DPS5020, which is also a powerful buck converter and i use it since 2 years for my small PV project to charge several batteries on a daily basis. Never had an issue with it. The only thing that causes problems is when you try to load the battery in reverse polarity - this typically destroys a diode or at leasst a fuse in the converter. I also use another cheap buck converter for PV-to-battery charge with no problems apart from reverse connection.
That's pretty good. Does it remember its settings between power outages? meaning, if I set the output to 5v fixed and set output to come on when power is applied, if power is removed from the main unit for a while like overnight, does it remember the voltage and amps settings before automatically powering it on?
Yes it does remember the voltage and current settings. Also, I want to remotely switch this device on and off depending on battery voltage. It looks like the little on/off slide switch can be externally controlled. More soon.
Could that old USB b allow you to send firmware update to it or allow computer control of the unit?
did you check the distance and the signal of the remote .. what type of connection ? how many meters in same room is it working ok ?
The wireless module looks like a nRF24L01+. My experiments yielded a range of 20-25 metres through walls (maybe double that line of sight).
How is the range on the remote? Does it work between the office and the shed?
Possibly not - the wireless module looks like a nRF24L01+
not a bad price
It makes an awesome power supply with its handy control unit. But don't do what I did by setting the display to Chinese on a similar control unit. It was almost impossible to figure out how to set it back to English. Lol.
Hmm seems like a good Buck converter, are you waiting for the rain to start before going back to the shed???
The shed is a complex place. It gets very hot (and very cold). It gets damp in winter. It's the best place for lithium battery experiments (especially charging). It's not the best place for sensitive (or valuable) electronics.
@@JulianIlett you have valuable Electronics??? 🙂
Admittedly, not much.
Does Juntek do a buck\boost converter?
Wondering what/where i could use this thing, A variable power supply? im unsure what application it could have.
at £127 I'd need to have a usefor it before buying
@@dantronics1682 Trying to think of a purpose , High amp step down power conversion for high power applications? Not sure how secure the wireless feature is and if setup in a permanent installation would you need to keep changing the settings? I dont know 🙂
Well, my application will be running a high current 12V load (Antminer) from a 25V solar charged battery.
@@JulianIlett I have one that I use to drop 50v to 25v for an inverter (700w) but its not digital. just a pot to set the voltage, just bought another since its so cheap (£30)
@@JulianIlett Hmm interesting , I do have a 30V odd car battery sat here doing doing nothing maybe it could be used on that but im unsure how secure the wireless thing is , odds are low but you never know if you get some joker changing your settings 😀.
curious how it would hand a solar panel at input.
A buck converter measures output voltage (and sometime current) and uses those measurements to control PWM in a feedback loop. A solar charge controller measures Input voltage and current (to control the MPPT mechanism) as well as output voltage and current (to properly charge the battery (CC/CV).
How did this end?
Kicking myself in the a** for re wiring my solar array to a 2s config. Yeah sure I get more power production earlier and later into the day and better cloudy weather performance but now my array can average 85v (can dip into the low to mid 70’s. Technically rated for 77.4vmpp) and I can no longer use my 1500w dc to dc boost converter to solar charge my 72v 3.5kWh ebike since it caps at 60v input 😢
If you put this between high voltage solar and low voltage batery with pwm controller, if you set voltage close to battery voltage, will it rise efficiency?
No, because this unit isn't 100% efficient and the total efficiency is the multiple of both the units
However, now you can charge your batteries using the lower voltage pwm charger
@@subhobroto I mean teoreticly if i have 50v panel and 12v battery, on full sun i would get on PWM like 1/4 of full power, so if you put this buck between and set output voltage lets say 13-15V, i should get like 90% of full power which would come from mppt charge controller, or am i wrong?
I think the issue here is that it doesn't monitor the input current and input voltage. If you add this on the input side you could control the buck converters output via a micro controller to behave similar to an MPPT controller (no more pwm controller needed).
@@Ether_Void its not the issue, changing power from 20 to 90percent is good a few more percent from mppt tracking does not matter much.
@@rm6857 In that case I don't really understand the issue.
As subhobrotosinha287 mentioned you can't increase conversion efficiency by adding more converters. A let's say 90% efficient converter can't bring back the power that is lost somewhere else.
A PWM controller is inefficient because it doesn't operate near the maximum power point of the solar panel.
If your unit doesn't charge well above 90% it might be a safety feature or something to prevent deep cycling.
Hard to say without details.
Ripple?
I/(2fC)
@@JulianIlett Think I meant NOISE.
Why? You already have a 12v battery that can power anything...
Because it would be nice to use a higher Voltage between solar panels and the unit and then step it down to battery Voltage if the battery and the panels are a good distance apart.
more junk???? lol
hope Juntek is not JunkTech
I don't know if this product has a lot of appeal to your "historical" audience. Yes, the format is good, like years before. But the product choice is bad.
I think we "general home tinkerers" are not as sharply focused on "garden / home / powering" as you. Sad.
Hi --just wanted to let you know why i'm banning your channel...I now automatically click on "Don't recommend channel" anytime i see the words "Ultimate..., World's..., Biggest.., Most Amazing, Incredible" I even ban channels with "Don't do..." and "This is the way to..." anyone that claims to have all the answers, these channels clearly don't know what they are talking about and are only using the title as Click Bait. The world is dynamic, always changing, this Buck Converter, may be ultimate today, but not next week when a new product comes out. that will make you look stupid for posting this video. And I have a bunch of Buck/Boost regulators...they're all ultimate...because they all work. The other problem is that anyone with the "perfect product," is probably being paid to post a commercial, just another reason to ban a channel. thank you.
Whoa! Who peed in your Cheerios? Wow. I think somebody needs a nap. I guess you didn't see the question mark?
was unaware users could ban channels , Unless they are some google employee with the keys to the server cabinet.
I can somewhat see where you're coming from in that the internet as a whole has become clickbaity, however entirely cutting out every single person, channel, blog, website, or whatever, that uses such an unoffensive word as "Ultimate" is an utterly insane and petty extreme in the opposite direction and I have a suspicion that you'll find you're in the minority and you're not going to change anyone's mind by taking such a hard stance...
Ironic. "Ban your channel" sounds a bit clickbaity to me - when all you've done is choose not to watch.
The "Ultimate" in this case has some context to it if you have watched any of the earlier videos, there were a bunch of DIY Buck/Boost converters (on the MuPPeT board) which were often controlled via an Arduino. In this sense it is the "Ultimate" one in that series as it has the highest power rating and same digital control (if not better) than the MuPPeT versions.
JUNteK. somehow when you said it has a wireless controller the ultimate word lost its meaning (for me)...