HP Server PSUs - 12 Volts - Lots of Amps 

Thanks for that :)

Most site i have seen with these don’t use them, instead they get similar data via the iRMC, especially where they have more than one brand of server in their racks.

What Pot is needed and where is it connected? Can you link any info pls?

​@@stewartrv My 460W model ran at 12.25v and the inbuilt pot only adjusted up to 12.5v. I added a 43k Ohm resistor from ground to one of the legs of the screw, and got 13.8 - 14.2v. Problem is then under load it switched off, so must have a max limit of 13.8v (now the lowest setting). It works fine now, but it was on the cusp of tripping and the screw is a bit sensitive. So I'd prefer a lower resistor value to ensure it always runs (e.g 13.4 - 13.8v). The quiet PSU fan also got a bit louder. I use it for a Xiegu G90 ham radio (20W RF, RX 0.6A, TX 2-5A) and hear it'll run full power at

Interesting. Makes me wanna research it some.

@@blackz06 PMBus ... the specs are available for the current (and older) versions... www.pmbus.org/Specifications/CurrentSpecifications pmbus.org/Specifications/OlderSpecifications If you orient the edge connector on the PSU so that the large power connectors are on the right and the group of small data connectors are on the left, as you look into the back of the PSU ... ... the I2C PMBus pins are the two rightmost small connectors (facing downwards) The wikipedia page on "Power Management Bus" mentions various chips and firmwares that implement the spec and provide for graphical interfaces... although, being I2C you could write your own using an appropriate microcontroller such as Arduino, Atmel, PIC, etc. Usually these server PSUs give a LOT of power conditioning information, temperature, fan-speed, 100% fan-test, current limits, etc. I don't know about HP, but my Dell ones also provide Input and Output Voltage and Amps - which is great for monitoring efficiency, impending failure and line condition. The slot also provides an always on, low current, supply for powering a management IC... it will even power a raspberry PI very nicely if driven through a 12v-to-USB power regulator. So, you could browse into your power supply from anywhere in the word and monitor it or turn it on/off. Have fun : D

@@garychap8384 Wow, thanks for the info!

Server rooms are normally the polar opposite of clean rooms; I suspect the 'refurbishment' process for the power supply is blowing the dust out.

The server rooms I worked in were clinically clean and needed to be. Apart from servers for local Government we had the servers for UK Post Office which had so many fans they sounded like jet airplanes taking off when they were all powered up. Any dust in the rooms would very quickly have found a home inside them but they were clean when opened.

I know - I did it just to annoy the OCD brigade.

$50! Prices must have gone through the roof!

@@mikewillis1592 Shipping:GBP 25.99

Ouch. I bought my 460w used for £9 (including £3 delivery in the UK).

Thanks Heine. I just connected a PP3 9v battery to that connector and it turned on the PSU. So I can switch it on and off without using that click switch (with its annoying bistable action). Cheers :)

@@JulianIlett You can just connect pin 37 (always on 12v) to the right pin of the "main detection port" (12V).

solar powered or you like to pay the power generators that much, maybe have shares in that company ?

@@jyvben1520 no on both

how are they noise wise? is tolerable to sit near them for hours? thank you

The lowest grade of server power supply is an 80+silver. Most are gold and a smaller fraction are platinum or titanium.

Same volts on mine, I added a 43k resistor (between a pot leg and ground) and got 13.8 - 14.2v. A bit too much as it trips above 13.8v under load.

After a few days of tests, I reckon they return about 20% of the electricity cost. Not a bad 'cash back'. Also they produce a very dry heat - ideal for the shed. But the noise - OMG the noise.

@@JulianIlett Any thoughts on thermostatic control and quieter fans? If the devices have thermometers in built you might be able to get much of it as a software patch.

They are thermostatically controlled - the fans change speed periodically - they also run slower on colder days. It's also possible to lower the ASIC clock speed - less heat is produced and the fans run proportionately slower. But I need around 2kW to keep the shed warm - that's both Antminers running flat out.

@@JulianIlett You could build a small shed or lean to beside your main shed and use the fans to pump the heat through some ducting. Lots of insulation to keep the heat in and noise out and your golden. Just a thought

The large transformer-looking device is the switching transformer, and the pcb trace is for current measurement (i assume).

Warm to the touch

I didn't freeze frame and pick off the model numbers, but this family of supplies come in different efficiency ratings. The lowest are 80+gold level. You are right that the efficiency peaks at 50% utilization.

@@davidwillmore That's interesting. Given that servers run continuously for years on end, and given the amount of money that server farms end up paying for electricity and for air conditioning to get rid of excess heat, I would have guessed that spending a few bucks extra for higher efficiency would always be a no-brainer...

@@ats89117 It is, but the supplies Julian is talking about are the ones being removed from service, so they are the older and less efficient ones. If we looked at the ones in service, I would expect them to be more efficient then the ones we are seeing surplus. Keep in mind that, at these efficiencies, the power saved going from one grade to the next is very little. I.e. going from 92 to 94 doesn't save much power as there is very little being wasted.

Yes - and I'm pretty sure the 750W unit should do the same (it's probably badly adjusted).

@@JulianIlett Yeah, otherwise it doesn't make sense that the 1200W one needs less cooling than 750W one. Thanks for the info anyway, I'll go buy one right now! They're so ridiculously cheap!

@@JulianIlett Just an update: I've bought a 750W and a 1200W model. 1200W one is just like yours, while for 750W I went with a fancier 80+ Titanium one (HSTNS-PL34). They behave exactly like you described: 1200W is semi-passive, 750W runs the fan all the time, even when off (it's actually really quiet though!). I guess the explanation could be that the 750W one is manufactured by LITE-ON, while 1200W is from Delta Electronics. If I were you, I wouldn't mess with the potentiometers - they probably set various important things like output voltage, protection thresholds, etc., and very unlikely - the fan curve). Instead, I'd try interfacing the PSU via I2C/PMBUS. You can normally use this to set fan speed to anything that is above the PSU's internal target.

Are they configured as synchronous rectifiers or 'ideal diodes'?

@@cambridgemart2075 synchronous rectifiers

Yes it s for standby

The servers these PSUs are meant for have a dedicated remote control system integrated, called Integrated LighsOut, or ILO. You can completely shut down the server and still have full remote control ability, so if you need to enter the BIOS or RAID card for thousands of miles away you can do it.

I guess I could use the standby 12V to power my remote control receiver :)

@@JulianIlett Yes you could, the PSU will always supply the 12V as long as it has mains

He just did a video about that recently!

@@SouthSideChiTown ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-MNV5zf9Ll4Q.html

@@douro20 Yeah, I'm sure he did but I can't find it. Have a link to it?

@@douro20 thank you.

Well, I suppose a relay is a sort of robotic arm - it just has very limited movement :)

It broke. No, the miners make a loss :)

@@JulianIlett what exactly was the purpose of the miners again? besides making a racket in the shed

@@Space_Reptile heat! 😂

That wouldn't work in winter - there's no sun :)

@@JulianIlett Seattle is pretty notorious for gloomy weather but people are building these "pop can heaters" for small studios/shops. It would be curious to see how effective it would be in your climate. love the videos still!

Not a good idea. You are loosing money on them (big time). You can look up his miners, and see what others earn with them here: www.asicminervalue.com/

@@deslomeslager that is relative. If his power comes from solar it is "free" (besides cost of panel and battery buffer) + it is a heater in winter . Sure you won't make money . But my thought is not about that i would like a video on the more electronic side and power consuption side of this miners

@@ixi12Vl It's a pretty good idea if you're using it as a heater, but otherwise even for "free" it's a bad idea because using the electricity you generate rather than grid power is roughly 10x more efficient than using it to make money.

On sunny days, I have connected a miner to my 240W solar panel (through the PowerOak unit). But it will only run at the minimum clock speed so around $0.01 is all it earns.

I see.

That's one of the many uses I have for them

Same here. But i also use a 48v power supply from wireless tower surplus since you can't get max watt from high power charger with 12v psu

Most server PSU's are packed so tight there is no room for a trimmer pot, and also packed so tight it is almost impossible to locate the feedback. Good luck!

@@rich1051414 they have trimmer pots but the range is not very wide. and most will overvoltage tripout before about 13.8V.

​@@TheEmbeddedHobbyist Hmm, mine had laser trimmed printed carbon resistors. If the overvoltage protection is detected from the feedback/sense, sticking your own pot there could be a solution, as long as nothing gets ran out of spec.

@@rich1051414 The one I have i converted to 13.8V to power radio's. Found the voltage control pot and added a fixed resistor to the board to allow it to addjust higher. could not get to 13.8V as it cut at 13.7V, so left it set to 13.6V close enough. With no circuit dia, i did not want to poke around too much to try and get the extra 0.2V. But i expect these are designed to be very effecient at 12V and pushing them away could drop it and cause excessive heat.

​@@TheEmbeddedHobbyist On my 460w PSU I added 43k and got 13.8 - 14.2v, but found under load it'd trip above 13.8v. It runs my Xiegu G90 fine but I'd prefer a lower value as it's so close to tripping, and the screw is finnicky. One time it didn't power up. I read on QRZ someone had e.g a 100W icom but needs to run a battery or capacitors inline, as theirs can't handle the sudden bursts on TX.

Interesting use case but why not just hack in a 4s or 5s lipo? A small pack only costs about $10-15.

@@vgamesx1 Sometimes corded is better. A small cheap pack isn't going to work nearly as well.

@@whitcwa I disagree, a higher voltage of course means it can draw more power and even a small lipo can have ratings at 30C or higher, basically meaning a 2Ah battery can deliver up to 60A, so it goes without saying that a slightly bigger 3Ah+ battery at 50C is going to be able to provide a lot more than 50A, but sure a cord is always going to last longer than any battery.

I once used an old motorbike battery to power an 18v nicad Dewalt drill, so when I got my PSU just to test it I popped the crocodile clips straight on the copper strip and it worked fine. It ran slow of course. In comparison I tried a Dell laptop PSU and it tripped, unless pressing the trigger gently (and only for a second I think).

@@dazednconfused31337 Yeah, a laptop supply isn't nearly enough. You need a 500W or better supply to avoid triggering the over current shutdown.

If I do start twiddling the fan pot (with the PSU powered up), I'll use my ceramic screwdrivers.

Go back 3 videos :)

@@JulianIlett ok

He has shown it in previous videos, it is based on one of Big Clive's Gallium boards.

Who would remove the fan from these PSUs?

@@JulianIlett wasn't removed, just made the mistake of assuming that all of them have a built-in fans, but apparently some models don't. (dps-460bb b)

Yep, me too! I guess they are cooled by driven fans in situ, or something. They are fine with low power though as i just use them as converted project power supplies. Very good quality and cheap for that use....around $5 i paid! Even my 1200w version only cost $20 & free shipping from Amazon.

I use Prohashing :)

@@JulianIlett i went with nicehash as it will oayout in bitcoin that tends to change often so can gain alot more money when it claimes the thing i like most about my old miner is when the miner paied for its power use in winter all that free heat

He says elsewhere he gets about 20% of electricity cost, so certainly no moneymaker, but better than 0% return off a resistive heater...

Because voltage regulation is a thing

Ryan Malin I suppose the miners might not like 13.8v on a sunny day... Some big linear regulators might be silent and kept the shed warm?!

It doesn't add up. On a dull day, my 240W solar panel delivers about 20W. The shed needs more like 2kW to keep it warm.

Its the stage of the food chain before ant eater

@@jasonmonk7336 True, but you're a very naughty boy! Lol!

800 Satoshis

I've not looked into that :)

Use a normal r/c lipo / life charger that runs on 12 volts and power that from one of them.

@@steverpcb I need something automatic that will start charging when I plug it in the mains These power supplies can deliver serious amps and I need around 30amps to fast charge my lifepo4

@@marbesky 4s needs balancing so just putting 14.6 across it is not an option.

@@steverpcb I have an active balancer installed and a 60a bms with top balance I just need high current (30amps) to charge fast

I'm not quite sure, but you should be able to adjust a pot somewhere to increase the output voltage ,, have a look a 'fred in the shed' on YT he has adjusted PCU's to 13.8v DC to run ham radios !! ?

Think yourself lucky you only had 27 minutes of it :)

These particular ones are worthless because crypto is so hard to mine now that a miner from a few years ago will loose money hand over fist (I think Julian has a video showing how much money they actually make, he made about 0.001 cents in his test) On the other hand he is using them as heaters so he would be using that power to heat the shed anyway. On the other other hand a £20 toaster would heat the shed too and be much cheaper than all these ebay parts. He clearly just does it because its interesting.

Insulation Warehouse have one too :)

Bye.

@@JulianIlett I'll still keep dropping by, just hope you'll get better sound, soon. Always good vids.

Hence the fan heater - I'll use it in future videos.