EEVblog Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: Simon on August 24, 2014, 12:37:22 pm
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I'm designing a project with lots of outputs each supplying up to 13A & 12V, now with 35 outputs that in theory is 5+KW but to be conservative and assume that all outputs will not work at once lets say that I want 1-1.2KW PSU's. Where would i buy such as item ? ATX PSU's would be great but much of the capacity is actually available at other voltages, one I looked at could do 2x42A rails which wastes 200W although that is not bad i suppose. Is it worth getting dedicated supplies ? or are ATX supplies best bang for buck.
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Atx power supplies are close to best bang for buck.
Or if you can find second hand high power server power supplies. Best i have seen had 4 kW available at 12v output!
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Most high-efficiency PC PSUs over 700W use DC-DC converters from 12V for 3.3V and 5V outputs.
Go on Newegg.com, select 80+ Gold/Platinum/Titanium-rated PSUs over 1000W and you should see that most of them can go up to full-load on 12V alone.
Examples:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817438011 (http://www.newegg.com/Product/Product.aspx?Item=N82E16817438011)
http://www.newegg.com/Product/Product.aspx?Item=N82E16817104142 (http://www.newegg.com/Product/Product.aspx?Item=N82E16817104142)
http://www.newegg.com/Product/Product.aspx?Item=N82E16817151109 (http://www.newegg.com/Product/Product.aspx?Item=N82E16817151109)
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Try these guys:
http://mch1689.en.made-in-china.com/product/cSLJwztxJUkW/China-1500W-30V-50A-Programmable-DC-Power-Supply-MCH-P3050-.html (http://mch1689.en.made-in-china.com/product/cSLJwztxJUkW/China-1500W-30V-50A-Programmable-DC-Power-Supply-MCH-P3050-.html)
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Does it have to be 12V? At that power level you will be losing a lot in resistive losses. If you can use a higher voltage then things may get easier, though you lose the option of PC PSUs. However for anything serious I'd avoid PC PSUs anyway as it can be hard to find decent quality.
MeanWell SP & RSP series go from 1 to 2kw
e.g. http://uk.mouser.com/ProductDetail/Mean-Well/SE-1000-12/?qs=sGAEpiMZZMsPs3th5F8koBOlc8SUmHBQmdQ4UosFvGs%3d (http://uk.mouser.com/ProductDetail/Mean-Well/SE-1000-12/?qs=sGAEpiMZZMsPs3th5F8koBOlc8SUmHBQmdQ4UosFvGs%3d)
Good quality High power PSUs can often be found cheaply as surplus
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Want cheap?
http://www.ebay.co.uk/itm/HP-440785-001-Power-supply-1200W-Hot-plug-1U-12V-DC-output-For-Proliant-DL580-G5-/301185987999?pt=US_Server_Power_Supplies&hash=item462015759f (http://www.ebay.co.uk/itm/HP-440785-001-Power-supply-1200W-Hot-plug-1U-12V-DC-output-For-Proliant-DL580-G5-/301185987999?pt=US_Server_Power_Supplies&hash=item462015759f)
Cant get cheaper watts than that. Downside is that you need some hack for the output connector and figuring out how to turn on server power supplies is not always the easiest task.
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Does it have to be 12V? At that power level you will be losing a lot in resistive losses. If you can use a higher voltage then things may get easier, though you lose the option of PC PSUs. However for anything serious I'd avoid PC PSUs anyway as it can be hard to find decent quality.
MeanWell SP & RSP series go from 1 to 2kw
e.g. http://uk.mouser.com/ProductDetail/Mean-Well/SE-1000-12/?qs=sGAEpiMZZMsPs3th5F8koBOlc8SUmHBQmdQ4UosFvGs%3d (http://uk.mouser.com/ProductDetail/Mean-Well/SE-1000-12/?qs=sGAEpiMZZMsPs3th5F8koBOlc8SUmHBQmdQ4UosFvGs%3d)
Good quality High power PSUs can often be found cheaply as surplus
48 v telecom power supplies are your next cheapo alternative. You can get Used 48v telecom/server power supplies for something like 20usd/eur/gbp per 2kW unit. But i guess simon was looking for 12volt powers.
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Does it have to be 12V? At that power level you will be losing a lot in resistive losses. If you can use a higher voltage then things may get easier, though you lose the option of PC PSUs. However for anything serious I'd avoid PC PSUs anyway as it can be hard to find decent quality.
MeanWell SP & RSP series go from 1 to 2kw
e.g. http://uk.mouser.com/ProductDetail/Mean-Well/SE-1000-12/?qs=sGAEpiMZZMsPs3th5F8koBOlc8SUmHBQmdQ4UosFvGs%3d (http://uk.mouser.com/ProductDetail/Mean-Well/SE-1000-12/?qs=sGAEpiMZZMsPs3th5F8koBOlc8SUmHBQmdQ4UosFvGs%3d)
Good quality High power PSUs can often be found cheaply as surplus
Not necessarily I'm just designing a dumb controller with 35 outputs that can handle 13A each, the actual power requirements will depend on the end use so I'm just curious as to what is out there that I can build into my product. 24V would be an option I'd want to have and this is where ATX power supplies can't help me anymore so any suggestions there ?
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24V would be an option I'd want to have and this is where ATX power supplies can't help me anymore so any suggestions there ?
A pair of PC PSUs in series can give you 24V but you need to disconnect the link between output ground and input ground - usually a solder pad around one of the mounting screws.
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Yea i guess that could be an option
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Farnell has some to choose from for instance 1821485
These have large MTBF ratings.
You can go with a PC powersupply, most high wattage supplies have a 12V rail only and as said above they use DC-DC converters for the lower voltages. Solder or disable those and you are good to go. There are (esp. in germany) a lot of pc websites that test the powersupplies. There are some that even state the brand of used elco's and their temperature, all measured voltages and currents under load(s) etc. etc.
You then see that there is no free ride, the PC powersupplies that scored the best at 500W (I searched for back then) are around 90+ euro and then you want 1kW so that is going extra, still extremely cheap compared to the Farnell listed powersupplies.
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Oh yea, that farnell thing is too expensive. ATX supplies it is.
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Ok then go and find a site that tears them down in their reviews and list component choices for example this one:
http://www.hardocp.com/article/2014/07/01/seasonic_platinum1200_power_supply_review/#.U_oDemAcSUk (http://www.hardocp.com/article/2014/07/01/seasonic_platinum1200_power_supply_review/#.U_oDemAcSUk)
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All i need to know now is that I can get the PSU i want in ATX format so that I can design cases for the correct amount of supplies as the need arises.
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ATX supplies pretty much all are the same size. and conveniently also all have the same hole mounting locations and the same need for a cutout in the back of the case. Just make sure you leave an air vent opening so you can get cooling air into the unit, and probably 5cm at the front to get the wiring looms through to the output connector. You probably want to make a custom case that takes 2 so it is easier to stack or to modify to get a 24V version.
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Well fortunately I work for a mechanical company and can sweet talk the metal shop supervisor into punching, folding and welding me anything i need if i produce profiles for him.
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TME.EU distributes MeanWell supplies and other Polish company, and MARITEX sells TDK-Lambda units. Take a look at their offerings, and maybe something will fit your spec.
Sent from my Samsung i9100 by Tapatalk
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Well fortunately I work for a mechanical company and can sweet talk the metal shop supervisor into punching, folding and welding me anything i need if i produce profiles for him.
Yes, but just remember that he might consider anything under 3mm plate to be too thin to work with......... I worked on aircraft tractors where a thin plate was 6mm, a standard one was 10mm and the strength members were 20mm steel plate. No laser cut there, bend around with a press and use a plasma cutter for profiling and a massive Miller rotary converter running the welder, using 1/4 inch welding rods. Generally the accidents resulted in chipped paint and the other thing was either flat mangled metal or had a hole in it. There were some that hit concrete walls, and that was the only thing that bent the plate. Cut out with plasma and weld in a new plate in those cases, the walls were made to Mil spec. 1 part cement, 1 part sand and 1 part stone, well mixed and properly cured with a minimum of 0.5m thickness and steel rebar every 10cm.
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We work is 1mm or 1.2mm unless we have to go bigger
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0.8mm steel as used in modern cars is likely to be best then, easy to form and likely to be easier to laser cut as well, along with being cheap if they already have a roll of it.
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Uh 0.9mm is small for us, I tend to have stuff punched out on bits of scrap.
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Well fortunately I work for a mechanical company and can sweet talk the metal shop supervisor into punching, folding and welding me anything i need if i produce profiles for him.
Maybe you can borrow one of his IGBT Inverter welders, find the schematic, bypass the HF arc start circuit and use the welder >:D!. Just kidding. That is really a bad idea ;D.
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I'm designing a project with lots of outputs each supplying up to 13A & 12V, now with 35 outputs that in theory is 5+KW but to be conservative and assume that all outputs will not work at once lets say that I want 1-1.2KW PSU's. Where would i buy such as item ? ATX PSU's would be great but much of the capacity is actually available at other voltages, one I looked at could do 2x42A rails which wastes 200W although that is not bad i suppose. Is it worth getting dedicated supplies ? or are ATX supplies best bang for buck.
I wouldn't use ATX power supplies. I recently got a couple of 2kW power supplies from Meanwell. They are not very expensive, have several monitor function and connection for sense wires.
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They normally deliver 60V open circuit though, but are a nice start.........
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£314 + vat for 1500W @12V for half that I can get 2.4KW in atx. It will depends on the final use anyway.
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They normally deliver 60V open circuit though, but are a nice start.........
What do ?
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What do ?
Modern IGBT inverter welders I mentioned earlier ;).
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What do ?
Modern IGBT inverter welders I mentioned earlier ;).
oh, yea, I'll certainly pass on that suggestion.
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Remembered our local guys do 1KW+
http://www.innovative.co.nz/ac-dc-power-supply/ (http://www.innovative.co.nz/ac-dc-power-supply/)
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Remembered our local guys do 1KW+
http://www.innovative.co.nz/ac-dc-power-supply/ (http://www.innovative.co.nz/ac-dc-power-supply/)
Some of their DIN mounted products looks like rebranded Puls PSU's, is it real manufacturer?
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Remembered our local guys do 1KW+
http://www.innovative.co.nz/ac-dc-power-supply/ (http://www.innovative.co.nz/ac-dc-power-supply/)
Some of their DIN mounted products looks like rebranded Puls PSU's, is it real manufacturer?
Yes, they design and build.
They also do big standby chargers for telco's here.
No doubt they may have some re-brand stuff....who hasn't?
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If you're in the US, I found http://powergatellc.com (http://powergatellc.com) has better prices on supplies than any of the big distributors.
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£314 + vat for 1500W @12V for half that I can get 2.4KW in atx. It will depends on the final use anyway.
I strongly doubt the ATX power supply can deliver 2.4kW 24/7 if it even can deliver 2.4kW at all. If this is for something remotely professional I recommend to get an industrial power supply. Even if it is just for the sense lines and a proper way to connect wires to it. Besides that your price seems to be wrong. I paid less for the 2kW PSUs I used.
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I strongly doubt the ATX power supply can deliver 2.4kW 24/7 if it even can deliver 2.4kW at all.
The 80+ Gold/Platnium/Titanium-rated PSUs are able to deliver their full 1000+W on the 12V rail. How long they can hold that up might be up for debate but Simon said his application is not going to run all outputs at max power at the same time so 24/7 at max power does not appear to be a requirement.
That said, those higher-quality ATX PSUs cost $150-250 each so after buying a pair, you are ~$100 away from being able to afford a RSP-2400-24 or similar for ~$450 and spare yourself the trouble of having to mod ATX PSUs to make them daisy-chainable. The extra convenience might very well be worth the extra $100.
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Yes it could end up cheaper with an industrial supply for higher powers.
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Look at the R/C market, big power supplies aren't that expensive.
http://robotbirds.com/catalog/index.php?cPath=9_161 (http://robotbirds.com/catalog/index.php?cPath=9_161)
I have this one:
http://robotbirds.com/catalog/product_info.php?cPath=9_161&products_id=1695 (http://robotbirds.com/catalog/product_info.php?cPath=9_161&products_id=1695)
I have used it several times to power a cordless drill. When you overload it the voltage will collapse, but it recovers quickly. It has a fan that is controlled by the output current.
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Highest power ATX supplies commercally avaliable are about 1600W at 12V rail. Good example would be EVGA Supernova G2 1600W, at 125A the ripple is 15mV, and voltage regulation is only 0.5%. Simply amazing. It even has 10 year warranty, lol. :D Current price at Newegg is 345$. But if you would use multiple PSUs, EVGA Supernova G2 1300W at 200$ would be best buy.
Bunch of excellent ATX PSUs tests are available at http://www.jonnyguru.com/ (http://www.jonnyguru.com/)
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HP ESP113 server power supplies have a nice edge connector on them that makes it easy to connect your own board. 32A at 12V. Cheap, reliable, and noisy :D
(http://i.imgur.com/8hHLdP0l.jpg) (http://imgur.com/8hHLdP0)
(http://i.imgur.com/BqwdT1Il.jpg) (http://imgur.com/BqwdT1I)
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ATX supplies actually make a lot of sense because the cabling distribution is already there. Due to the high currents I'd need cables to come in next to connectors and groups of switching components and so far I'm looking at 5 connectors with power either side of each connector and there are plenty of wires already on ATX power supplies.
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Most of the current on modern ATX supplies is wired up through the PCI-e power connectors (6pin and 8pin) rather than the main 24pin ATX plug.
I can't remember for sure, but I though the PCI-e socket, while it looks like a standard molex part, uses a proprietary pci-e keying. Something to check for sure before you invest too much in it. Those parts can be hard to find sometimes despite being in so many consumer products.
Edit
http://www.molex.com/pdm_docs/sd/457180002_sd.pdf (http://www.molex.com/pdm_docs/sd/457180002_sd.pdf)
PCI-E 6 pin is:
Square Keyed Keyed
Keyed Keyed Square
Normal Molex is:
Square Square Keyed
Keyed Keyed Square
Sooooo, a PCI-e plug on an ATX psu should fit into a normal molex socket, but not the other way around! (assuming a keyed pin fits ok into the square hole).
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You cut off the pc specific connectors at the end strip the wire add a standard ferrule for the diameter shrink it and put in a wago socket of your choice on your own board, whats the problem?
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Actually I just cut the wires to length, strip it and solder it straight to my board from previous experience the two 12V rails can be connected in parallel.
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£314 + vat for 1500W @12V for half that I can get 2.4KW in atx. It will depends on the final use anyway.
I strongly doubt the ATX power supply can deliver 2.4kW 24/7 if it even can deliver 2.4kW at all. If this is for something remotely professional I recommend to get an industrial power supply. Even if it is just for the sense lines and a proper way to connect wires to it. Besides that your price seems to be wrong. I paid less for the 2kW PSUs I used.
+1
There are lots of problems with using an ATX power supply including the minimum load needed on that 12V rail. Industrial power supplies give a guaranteed level of quality, reliability and performance which is not there with an ATX power supply.
Look for an industrial power supply from someone like MeanWell, Puls or Phoenix Contact. Use multiple power supplies in parallel if needed to give the required power level.
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That may be true for cheapo ATX PSUs, but 1000W+ PSUs are usually very high quality, and modern designs don't have problems with minimum load, nor minimum load on minor rails, etc. It's a viable solution, if Simon can't find industrial PSUs which are cheap and suit his needs.
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There are lots of problems with using an ATX power supply including the minimum load needed on that 12V rail.
The ATX 2.03 spec requires that PSUs be able to operate with no load at all on any rail to pass compliance and to reach 80+ Gold or higher certification, you kind of cannot afford wasting much power on internal shunts.
And then you have the Haswell power supply certification that requires that PSUs be able to cope with a 8A/µs load slew rate while remaining within 5% of specifications.
When you get into high-performance power supplies with traceable certifications (vs no-name brands with missing or fake certifications), the quality bar is actually pretty high.
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Actually I just cut the wires to length, strip it and solder it straight to my board from previous experience the two 12V rails can be connected in parallel.
How are the boards organised? For the project I needed the 2kW PSUs (6 in total) I used a standard eurocard frame and had busbars run along the backplane. It turned out to be a very compact solution.
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Well to solve the problem of burdening the PCB traces with large currents as I'm using 4/5 connectors I'll put power wires right next to each connector to break down power requirements.
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For my project I have used DIN41612 type F connectors. 16x3 rows (48 pins) with a current rating of 5.5A each.
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I'm designing a project with lots of outputs each supplying up to 13A & 12V, now with 35 outputs that in theory is 5+KW but to be conservative and assume that all outputs will not work at once lets say that I want 1-1.2KW PSU's. Where would i buy such as item ? ATX PSU's would be great but much of the capacity is actually available at other voltages, one I looked at could do 2x42A rails which wastes 200W although that is not bad i suppose. Is it worth getting dedicated supplies ? or are ATX supplies best bang for buck.
There are two kinds of 12v power unofficially speaking.
Data equipment 12v is standardized at 12.0v and there's a fairly tight regulation tolerance around 12.0v.
Data power supplies have limited surge capability and the protective circuit is specifically designed for it. They have very little tolerance for "hard switched loads". The power can go up and down when you wake up a hard drive after sleep or when the graphic card is loaded, but the peak di/dt is nothing like attaching a load with an empty capacitor or starting a motor across the line.
From my experience, they're very sensitive to this type of loading. I have had a few fair sized ATX power supply trip and shut down immediately from something as benign as hot plugging a CD-ROM drive. I'm not a power supply engineer, but this behavior can be intentional. This type of current peak associated with hard switching is not normal in a computer, so it might be seeing it as a short circuit and shutting down to prevent damage. While good for computer use, the nuisance trip can make it unpractical or even unusable.
power supplies for stationary use/testing of 12v nominal auto electric aims for the 14v which is the voltage in a car with the engine running. When the standing voltage is at 12.0v, it's already in trouble zone since battery charge is quite depleted by that point. Plug-in consumer products for automotive often require 14v if there's any sort of battery charging involved.
You didn't mention the type of load, response time, and surge current needed, flexibility and dependent/independent capability.
Do you need combined 1.5kW with 1.2kW per channel max with good independent regulation (one side unaffected by abruptly changing load on the other).
I would personally avoid the 100% split like 1.5kW, 750W per channel and insist on having at least a second channel with 10% or so of capacity on independent regulation so there's power power and control power.
http://www.americas.fujielectric.com/sites/default/files/1U12V3000W%20ACDC_0.pdf (http://www.americas.fujielectric.com/sites/default/files/1U12V3000W%20ACDC_0.pdf)
http://www.voltronics.com/ac-dc-switcher-grpi-gr (http://www.voltronics.com/ac-dc-switcher-grpi-gr)
Something designed as ground APU for automotive products or mechanically driven equipment (robotics, etc) would be more fit if the load is something like a power amplifier (mobile transmitter, audio power amp) or hard switched load like thermostatically controlled engine cooling fan.
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I'm not pushing more than 10A per output, I'm sure it will be fine and with all of the wire that will be involved there will be plenty of inductance to slow the pulse rise.