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- Опубликовано: 1 янв 2025
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Teardown Tuesday.
What's inside BK Precision's 8500 300W 120V/30A DC Electronic Load?
It is also known as the Itech 8512.
www.itech.sh/en...
Dave's DIY Simple Constant Current Dummy Load:
• EEVblog #102 - DIY Con...
I know why they laid out those DIP ICS the way they did, cause it looks more like a little town, when laying out PCBs I usually am not happy unless it looks cool, I will spend a day after laying a board out just trying to make it look nice
I love power supply stuff so this teardown was brilliant. thanks Dave.
Great video...nice useful piece of kit...need to add it to my wish list....
Look forward to the review.
"it smells good" and "those thick inputs, love emm" Omg! Haha, u are an awesome geek who doesnt feel ashamed admitting it, gotta love this guy!
I believe the red stuff you are calling "locktite" is actually a varnish called "Glyptal". I remember the stuff way back when I used to work on aircraft communication gear to keep stuff from vibrating loose, and to QC each connection.
I agree. my point was that a DB9 connector is for RS232 that has around -15 +15 levels where in this machine they used TTL levels but with a DB9 connector.
Yup! And most of the old stories are hard to share without photos or docs or whatever, both of which I kept very few of unfortunately.
Can't believe I had a piece of kit before Dave did! :) I have this one's little brother (The 150W one). Very handy.
The beep is going to be my new ringtone haha, keep up the great work Dave.
Apparently its an SST 8051 (not ST)
Thanks for sharing so much knowledge in such a casual, light manner. Very thankful. Great vid!!
SWAG: The TL084 DIP op-amps might be to drive the big MOSFET's,from the DAC? The DIP package might have higher dissipation,or something,so they went with that package. Just a guess!
Yeah, the x20 lens works great. Just need a stable mount for it because it has to get relatively close inside the gear to get those shots.
12:28. on my Maynuo M9714 it seem that this chip is a microcontroller C8051F340
And please share when done. There are plenty of DIY loads on the EEVblog forum.
Loved the whistling Dave, sounded like a love bird!
LOL...
Loving the sniffing of the new hardware. Build quality: 9; Bouquet: 10
The silicone guy went a bit nuts - even glued the white connectors that had latches!
Could be. But I don't see a reason to measure that, the stability and tolerance are designed-in, and the cal takes care of the absolute value.
The font panel rubber surround had to be removed first to remove the protective film. It's gone now.
Got one of these about 3 months ago for some SLA charger testing and transient testing of a MOSFET switching circuit. It is a great unit and so much nicer than my home built MOSFET load.
The PC control works well. There is Python code for driving the unit so Linux support is no problem. The DB9 is TTL and not a regular pinout. I made up a cable using a FTDI TTL232 cable and DB9 plug. Not isolated but I will dig up pinout if anyone is interested.
I've seen quite a few failed in monitors, but they are far better than say Capxon. In general, I think with the 1100 USD price tag, they could have used some better ones. Especially as a load tester gets very hot and is supposed to be reliable.
15:14 Spread out passives. Helps wave solder survival if SMT stuff isn't so close to TH stuff
I mentioned this in my DIY current load video. It would be software controlled. Pretty trivial to do.
Oh, we are definitely going to want to see your design.
Yeah, seriously good value. The street price is $900, as little as $750 on ebay, and the 150W version is under $500 on ebay. Great value for such a niche bit of test gear.
They might have put the xfmr up front to better balance the weight of the unit. The already have the heatsinks in the back, so if the xfrmr was there, too, it might have a clumsy, unbalanced feeling that could lead to dropping it (by we clumsy, unbalanced users).
Dave, What is the value of the power resistors? 0.02 ohm?
Best regards from Venezuela!
You should have the option to skip those after 5 seconds?
I absolute love these teardown vids!
The caps come off, but no 4mm support. Yes, a bit of a fail.
Yeah, it all depends on the system though. I've seen a documentary on a portion of the satellite tv wars that happened here in the States. Pretty interesting stuff that engineers were hired to do for corporate espionage. Acid that removed the plastic layers of a several hundred pin chip so he could figure out at the base layer and decode the chip's proprietary functions.
It bugs me so much when manufacturers etch out the labels on an IC...
You had to remove the front panel rubber to peel off the film.
datasheet links in the description! nice! and +1 on the industry stories etc.
Dave, I would say the Date-marking on the PCB is
2010 Sept. 06
and not 10. Sept. 2006
Sad but the first thing I would have done is rip the protective plastic film off the front :) Would have liked to see the structure of the heatsink behind the fan. Thanks for the vid
If the Mains traces were on top of the board, couldn't the heart sinc vibrate the solder resist coating/whatever off?
good job Dave :DD keep teardown tuesday alive :DDDDDD
Dave, whenever you do a video you have all the hi-tech stuff and you know about almost every component in there and where am I?:
"still thinking about a 555 chip in front of me!!!"
There are ads in the middle of the video?
Hey Dave, I noticed you read the test labels from left to right. Would you say it was more likely they put them on right to left? Not sure if it even matters which order these tests are done.
Sad to see Lelon caps on the PSU, as those are among the worst. On such a high end piece of kit, I'd expect decent caps...
I miss the story videos as well! Keep it up anyway!
So what's inside the huge metal boxes with the fans on?
hmm is that a DB9 connector but TTL voltage levels??
woh!!! transistors or voltage regulators placed adjacent to electro caps without a HEAT SINK!!!
there is always a small problem is a pcb
I have a unit that's very similar to this, a Beich CH8710C, 360v/30a/300w that I picked up on ebay for about $500 shipped.
What function do the components connected to the input of the electronic load ? emi filter? And if they are, what are they for? Are sources supposed to be tested that wouldn't distort the test?
lol i know. prior to y2k it was really easy! year first is always ymd. usually it's a 4 digit year these days so that's easy too. whenever it's a us or euro style date though, who knows?!
The CPU in this unit is a microchip "Flashflex" SST89E516R. I am trying to repair my unit. There was enough of the number left on the CPU to be able to identify the chip. There is no function of the load, but the front panel display works fine. I have done some digging and there seems to be an enable signal that controls the MOSFETS that is missing. I will post here if I manage to fix it.
Yes, they would have done the cal test last.
Nice cooling tunnels!
Those posts don't look like they take 4mm plugs, unless there are caps on the front. Also, grey terminals with red/black borders instead of coloured terminals. Testgear convenience Fail!
Try the 150W version for under $500 on ebay.
Teardowns are cool, but we miss such videos as 'Industry Storie', 'Tips and Tricks' and so on.
What is the point off rubbing the number off chips
I don't mind the freestanding TO220's, but I think the TO220's with the shitty thin tab are absolute crap (11:16).
also the rants, love em
Still have to test it though. Something can always go wro
If you know where to get the service manual, let me know.
Did you manage to get service manual?
Could be Precision Reference Test?
Dave has to get fresh air somewhere. After all he has to smell Sagan's "dummy loads" at home. :-)
It looks identical to Maynuo M9711/M9710 with premium price tag.
Because Maynuo is a chinese rip-off
Or it's the OEM...?
Who knows..))
Just taken delivery of a Maynuo M9812 and the only key difference I can see is the plethora of additional QC stickers in this puppy that Daves reviewing in his usual inimitable style.
A shaving ad, how fitting..
That @12:20 looks so non-professional but i assume that could be Atmel :)
Slows them down by maybe an hour tops in this case! Pointless. Easy to find out by the pinout.
Make an industry storie friday!
Yes! Power supplies!
Seems like some of the manufacturer's logo remains on that IC. Looks like maybe an S? Doesn't look like ST, and their stuff is usually laser etched ... anyone else have some ideas?
The problem with industry stories is that Dave doesn't have a 9 to 5 job anymore O_o
I agree, very wimpy!
I know, it's pointless. Not hard to figure out.
MIC Transformer ... in a BKP product ...
Yes, they aren't the best. But not the worst out there.
Congratulations on becoming popular enough to have your vids interrupted by advertising ;)
They WERE known to be crap. Please do some research - they completely revamped their quality control in the wake of the cap scandal. They are quite good these days.
(sniffing) .... smells good !!!!
Gals have Chanel No. 5, Lise Watier, Calvin Klein, Versace and Hugo Boss
Guys have Agilent, Tektronix, Fluke, B&K Precision and Rhode & Schwarz !!!
Are you a millionaire by any chance with the amazing lab you have??
price of this thing seriously....
No, just a 2 minute delay at the beginning, sorry for being ambiguous, but if you weren't popular, they wouldn't inject ads...
Looks like 2011. Most of the world uses the sane date format year-month-day.
I always sniff my test equipment when I pull it out of the box as well
That Indiana Jones theme song though...
Mostly fear of copy cats. It slows them down from being able to copy the system and creating knockoffs. Note how I say slows them down, not stops them.
Sometimes yes, sometimes no, depends on the ad.
big thumbs up
i like this
Dave needs a shave!
Right. The US is the exception.
1k usd? ... mmmmh..
Nice, I compared it to my DIY 1500W water-cooled simple load.
Arek R. Where is it?the video
There is no video about my 1500W electronic load...
+Arek R. make one then.
Nothing good to show, piece of shit, big luck that it works...
I dont care, still crap.
This video got so many views only due to the fact people saw the thumbnail and thought it would be interesting. However i would say 99% of the video viewers watched no mor than 5 minutes of this.