Optimizer (OP)
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February 22, 2016, 03:06:26 AM Last edit: October 04, 2016, 06:26:23 PM by Optimizer |
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Hi All, Sometime back I was trying to buy breakout boards for my DPS2000BB supplies but they were either out of stock or thermally inefficient. I design embedded power systems for my day job so I decided to go ahead and make my own. Here are the specs: 1) 3oz copper. I am finding this copper weight and planing generates less heat and leads to a more efficient power transfer. Unlike some of the other boards I’ve seen which use internal layers for primary current conduction, I utilized external layers for price and performance. The cooler the copper, the lower the resistance and the better the transfer. 2) I plan to run these hot with limited air flow, so I had to ensure operation at higher ambient temperatures. Through a few controlled tests I have verified continuous operation up to 70C (160F) ambient at full load on the DPS. My test load (shown below) consumed 166 Amps @12V continuous. This is slightly over the maximum recommended 164Amps. Measurement locations on board: 3) The PCBs are inspected to Class II per IPC-6012/13. The FR4 TG is 140C so it will hold up to higher ambient temperatures without delaminating. 4) I have placed a jumper for remote rebooting so no soldering is required. I have built quite a few of these and the pin headers are already in place with a jumper. This can be easily hooked up to an inexpensive remote rebooting solution. 5) There are (3) 3-pin headers for hooking up fans. 6) 12 PCI-e outputs. Nothing new here, but much more convenient than screw downs or bolting on cables. I was hoping to recoup my own cost, so I was hoping to unload my spares (and possibly some extras). If anyone is more serious about picking up some of these in quantity, I can always start another production run. I can sell a 5 pack of these for $275 USD including free shipping within the US. I'll also be selling these individually on my website. I can support purchases via PayPal or BTC, and I am more than happy to do escrow for BTC with OgNasty (buyer pays fees). I can order boards within the next two weeks, and have them shipped about two weeks after that. Thank you for taking the time to check it out. I usually keep these things to myself. If you have any questions feel free to fire away. PM me for details if there is interest in orders. Otherwise, let's keep it persistent for the world. www.price-technology.com-Optim
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sidehack
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February 22, 2016, 04:14:55 AM |
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I'm really hoping my boards were the "out of stock" rather than the heat problem ones. We build 'em with 14oz of copper between the 4 layers in each rail, which tested fine up to 196A draw in about 95F ambient. But no PCIe 6-pins.
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Optimizer (OP)
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February 22, 2016, 04:31:54 AM |
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@VirosaGITS I spent the beginning of my venture playing with the J4bberwock's. They were difficult to amass in quantity and given my ambient conditions those boards rose an additional 30+degrees Celsius. This is what I was seeing at full load for the J4bberwock: Versus what I am currently seeing on my unit: Given the lead times and my quick test, I made a lot specifically for myself to eek out a bit of efficiency. @sidehack I needed the 6-pinners. 14oz seems a tad much. Is that 3.5oz per layer and full coverage on all layers??? I would expect a 4-layer board around that weight to be overkill (to a point where the connectors might be tested). -Optim
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sidehack
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February 22, 2016, 04:37:12 AM |
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I'm not sure on the details (Novak did the PCBs for PSU boards) but I think it's 3oz outside 4oz inside. Could be 2oz outside 5oz inside. Many vias to help transfer internal heat to the surface. Also, I like overkill.
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Optimizer (OP)
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February 22, 2016, 04:43:12 AM |
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@sidehack
As do I. More importantly, I can appreciate the efficiency that level of 'overkill' brings to the system. That is assuming the designer strayed away from reliefing (which I realize many of these deisgns have). That appears to generate many other issues for these systems.
-Optim
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VirosaGITS
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February 22, 2016, 04:45:33 AM |
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@VirosaGITS I spent the beginning of my venture playing with the J4bberwock's. They were difficult to amass in quantity and given my ambient conditions those boards rose an additional 30+degrees Celsius. This is what I was seeing at full load for the J4bberwock: https://i.imgur.com/cvp4xfG.jpgVersus what I am currently seeing on my unit: https://i.imgur.com/efWCCMg.jpg?1Given the lead times and my quick test, I made a lot specifically for myself to eek out a bit of efficiency. Thanks for humoring me. In depth technicalities is a bit beyond me but i like amassing the general/conceptual knowledge. 100F seem pretty close to body temperature i believe? Thats like 37C? That seem cool to me. So you mean its a power waste issue? But it would be how much? 2-3watts waste?
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Optimizer (OP)
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February 22, 2016, 04:51:58 AM |
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@VirosaGITS I spent the beginning of my venture playing with the J4bberwock's. They were difficult to amass in quantity and given my ambient conditions those boards rose an additional 30+degrees Celsius. This is what I was seeing at full load for the J4bberwock: https://i.imgur.com/cvp4xfG.jpgVersus what I am currently seeing on my unit: https://i.imgur.com/efWCCMg.jpg?1Given the lead times and my quick test, I made a lot specifically for myself to eek out a bit of efficiency. Thanks for humoring me. In depth technicalities is a bit beyond me but i like amassing the general/conceptual knowledge. 100F seem pretty close to body temperature i believe? Thats like 37C? That seem cool to me. So you mean its a power waste issue? But it would be how much? 2-3watts waste? Well, the issue scales with load. The power lost in these systems is equivalent to I^2*R. Where I is the current transferred and R is the resistance of the board. The resistivity of copper also scales with temperature. The hotter these boards get, the less efficient they are. That being said, my concern is always I. Since I is squared in that power loss relationship, R needs to be as small as possible (Since we can't change I without scaling the system). -Optim
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VirosaGITS
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February 22, 2016, 05:02:13 AM |
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@VirosaGITS I spent the beginning of my venture playing with the J4bberwock's. They were difficult to amass in quantity and given my ambient conditions those boards rose an additional 30+degrees Celsius. This is what I was seeing at full load for the J4bberwock: https://i.imgur.com/cvp4xfG.jpgVersus what I am currently seeing on my unit: https://i.imgur.com/efWCCMg.jpg?1Given the lead times and my quick test, I made a lot specifically for myself to eek out a bit of efficiency. Thanks for humoring me. In depth technicalities is a bit beyond me but i like amassing the general/conceptual knowledge. 100F seem pretty close to body temperature i believe? Thats like 37C? That seem cool to me. So you mean its a power waste issue? But it would be how much? 2-3watts waste? Well, the issue scales with load. The power lost in these systems is equivalent to I^2*R. Where I is the current transferred and R is the resistance of the board. The resistivity of copper also scales with temperature. The hotter these boards get, the less efficient they are. That being said, my concern is always I. Since I is squared in that power loss relationship, R needs to be as small as possible (Since we can't change I without scaling the system). -Optim That make sense, if you ever get some watt waste numbers at different temperature, that could be cool too. I'll stay subbed to the thread. Cheers, you're new but you seem to know your shit. Welcome (again?) to the forum and thanks for the lesson.
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Optimizer (OP)
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February 22, 2016, 05:27:38 AM |
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@VirosaGITS I spent the beginning of my venture playing with the J4bberwock's. They were difficult to amass in quantity and given my ambient conditions those boards rose an additional 30+degrees Celsius. This is what I was seeing at full load for the J4bberwock: https://i.imgur.com/cvp4xfG.jpgVersus what I am currently seeing on my unit: https://i.imgur.com/efWCCMg.jpg?1Given the lead times and my quick test, I made a lot specifically for myself to eek out a bit of efficiency. Thanks for humoring me. In depth technicalities is a bit beyond me but i like amassing the general/conceptual knowledge. 100F seem pretty close to body temperature i believe? Thats like 37C? That seem cool to me. So you mean its a power waste issue? But it would be how much? 2-3watts waste? Well, the issue scales with load. The power lost in these systems is equivalent to I^2*R. Where I is the current transferred and R is the resistance of the board. The resistivity of copper also scales with temperature. The hotter these boards get, the less efficient they are. That being said, my concern is always I. Since I is squared in that power loss relationship, R needs to be as small as possible (Since we can't change I without scaling the system). -Optim That make sense, if you ever get some watt waste numbers at different temperature, that could be cool too. I'll stay subbed to the thread. Cheers, you're new but you seem to know your shit. Welcome (again?) to the forum and thanks for the lesson. I am a newbie. I am mostly playing around with this out of interest. I may be able to play around with that load stand on Wednesday-ish. I will let you know if I have some more exact numbers. My rule of thumb when there is no airflow is that the hotter it is, the less efficient (this does change with surface area). I also like the reliability aspect. Cooler things last longer. -Optim
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MarkAz
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February 22, 2016, 05:31:09 AM |
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Interesting - I use almost exclusively Jabberwocks boards and haven't had any issues with them, but I'm generally running well under the limit of the PSU's. They definitely do seem to run warm, so when I made my fan adapter for the dual DPS2000BB's, I actually had it hang over the board to blow some air on it - easy enough to do and worth the extra effort. Can you explain a bit about your test rig? I'm assuming those are some industrial resistors just basically converting power into heat, correct? I like that you actually did pure testing with it, and didn't just hook up a S7 and call it good. Also, I'm a bit confused about what exactly you're offering - do you have these boards available now, or do they ship in 4 weeks?
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kilo17
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February 22, 2016, 05:47:41 AM |
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I must say that I am impressed with the attention to detail, although I would say look at the double 2000 board he makes and you will see the way it becomes the New standard. A lot easier to hook up fans to 2 units and also a lot more versatile for hooking up miners. A single 2000 can run 1 s7 while the double can run 3 and stay cool
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Bitcoin Will Only Succeed If The Community That Supports It Gets Support - Support Home Miners & Mining
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Optimizer (OP)
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February 22, 2016, 06:30:42 AM |
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Interesting - I use almost exclusively Jabberwocks boards and haven't had any issues with them, but I'm generally running well under the limit of the PSU's. They definitely do seem to run warm, so when I made my fan adapter for the dual DPS2000BB's, I actually had it hang over the board to blow some air on it - easy enough to do and worth the extra effort. Can you explain a bit about your test rig? I'm assuming those are some industrial resistors just basically converting power into heat, correct? I like that you actually did pure testing with it, and didn't just hook up a S7 and call it good. Also, I'm a bit confused about what exactly you're offering - do you have these boards available now, or do they ship in 4 weeks? Yes. Those are just resistors. I ran 14 of them in parallel to get ~72mOhm load. With the supply across them, they will dissipate the 2kW. That is why I threw the fan in the mix. Those resistors will get very, very hot during this test. During this test, this subjects the power adapter board to the full load (~166A) to measure worst case temperature and dissipation. I measured the voltage across the load with a DMM. The temperature was measured with FLIR and a National Instruments thermocouple. http://www.ni.com/product-documentation/10632/en/I've thrown a current probe onto the power input to verify efficiency and calculated the current based on the measured load resistance of 72.2mOhm. This isn't the most accurate calculation, but it should get me right around what I need. I do enjoy a science fair and I rarely get to fully test things at work with the corporate overhead. I have a spare 50 PCBs sitting on my desk and I was hoping to unload. When that stock runs out, I would have to order more and the two week extra bit of time would get into the mix. I do not have all of the parts for assembly, but those may be acquired within a day or two and be built in time (the approximate 1-2 weeks before shipment). PM me for details if you are interested.
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Optimizer (OP)
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February 22, 2016, 06:40:04 AM Last edit: February 22, 2016, 08:08:30 AM by Optimizer |
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I must say that I am impressed with the attention to detail, although I would say look at the double 2000 board he makes and you will see the way it becomes the New standard. A lot easier to hook up fans to 2 units and also a lot more versatile for hooking up miners. A single 2000 can run 1 s7 while the double can run 3 and stay cool I come from an area of engineering where there is an emphasis on reliability. This has led to a bit of paranoia in my personal ventures. In your mining topology, if a single supply were to fail, three miners would drop out of the system. With the single board solution, I am rocking a 1:1 supply failure to miner failure ratio. It makes me a bit more comfortable; to each his own as they say. I also find that the efficiency of these supplies taper off with max load (This appears to be a phase shifted bridge supply). I have yet to see an actual efficiency curve for the DPS2000BB (I have yet to measure as well...), but I imagine the dual supply configuration might actually hurt the W/hash slightly. This is purely speculation, I need to dig for a while to know for sure. -Optim
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NotFuzzyWarm
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February 22, 2016, 06:15:19 PM Last edit: February 22, 2016, 08:41:25 PM by NotFuzzyWarm |
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Optim, here ya go: Discussion about the 2kw supply - but curves for the IBM DPS2500BB https://litecointalk.org/index.php?topic=5854.0
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Prelude
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February 22, 2016, 06:49:20 PM |
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Those are efficiency numbers for DPS2500BB, NOT DPS2000BB. Big difference, and the numbers can't be applied to the 2000w version.
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NotFuzzyWarm
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February 22, 2016, 07:09:00 PM |
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Well poop! Yer, right, everywhere it's about the 2kw supply - except for the performance curves..... Post edited to reflect that.
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Optimizer (OP)
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February 22, 2016, 07:20:16 PM |
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@NotFuzzyWarm and @Prelude
Thank you for the post. It was close. I'm sure the DPS2000BB curve is similar to this. There is likely a crest around 50-60% that tapers off slightly as the supply approaches 100%. I might check one supply over here to get a ball park between 50% load and 100% load. Will update this thread later in the week.
-Optim
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MarkAz
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February 22, 2016, 07:21:41 PM |
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All in all very cool - and I love that there's some other good hardware guys coming into the space, it takes a village. About half of my 2000BB's are running the 4k board, and while I haven't had any failure yet, I certainly have had failures in the past... but as he pointed out, there's a practical advantage to pairs of those 2000BB's - but what I did with my single boards was just reverse the orientation of the miners so the plug was on the inside instead of out, and then you can have cables going out in either direction, and still use the same general configuration of back-to-back 2000BB's. The only downside of this is that the fans aren't blocked on the outside, like they are with the 4k board, but if you're using high SP fans I haven't found that it matters much. On one of my units I experimented with using foam insulation strips around the perimeter of the fan mount, and it made virtually zero difference, not worth the time it took to do it. NotFuzzyWarm brought up the 2500BB, would these breakouts be compatible? If so, that might be VERY awesome, as you could easily run 4 A6's on 2x 2500BB, getting almost full utilization out of the PSU. I imagine the extra thermal headroom your design has would make a BIG difference in this case. So I'll take a couple of those to check out - but 5 isn't a great number because I'm going to use them in pairs, but how about either 4 or 6? PM me and we can work out the details if that's acceptable to you.
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philipma1957
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February 22, 2016, 07:45:49 PM |
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So. Do I get to adjust volts with a simple switch?
Will they work with the 2500 model psu.
Would you consider making a dual board?
I may want a few singles if they work with the 2500 model psu.
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