Poser supply connector


Am looking at getting a BPI-W2 to set up as a RAID server, The details on the power input are incredibly vague. What, exactly, is a 5x2mm connector? The pictures aren’t clear. I’m assuming it’s one of those dc jacks, but 5x2mm is no size I’ve ever come across and there’s no indication of whether it’s centre negative or positive.

Does anyone have a link to a detailed description of an example PSU? Preferably one I could buy in the UK, preferably not Ali Express or similar, but that will do in the absence of anything else.

Many thanks :slight_smile:

I have used part spec sheet for power socket I found somewhere here:DC090.pdf (37,6 KB)

and picked universal laptop charger similar to this one: https://allegro.pl/oferta/uniwersalny-zasilacz-do-laptopa-ladowarka-sieciowy-9976564684

5.5x2.5mm fits nicely

for RAID you will need 3A+ rating on power brick (2A is enough to power single 2.5’’ HDD - reboots due to voltage drop during booting process while trying to spinup 2x HDD)

2A brick via barrel + usb-c smartphone charger would work as well - you can power board alone using usb-c and smartphone charger ;p

Hi, Many thanks for the reply.

I’d seen that specc for the connector, but it’s good to know you have used a 2.5mm pin version. Slightly alarming that we need a 3A supply and that connector is rated at 1A!

If it’s centre positive, then I think this would do the trick for me:


Do you know whether it is centre positive please?


googled my brick and this is exactly the one i have http://www.vakomtek.com/EN-H100/products/325/st-5424bk.html

unfortunately there is no polarity info on sticker or in this website

That supply is one of those where you can reverse the polatiry depending how you plug in the used plug to the universal part of the power supply lead. So either you were lucky when you first plugged it in or you got it wrong, protection circuitry preventing you from damaging it and and then plugged it in the righ way :smiley:

I’ve ordered a board and will just have to work out what it is when I have in front of me by using my meter to detect whether it’s the centre or barrel connected to ground.

Thanks again :slight_smile:

OK, in case this helps, here’s what I have ascertained now the device has turned up.

It is centre positive and the universal plug system reveals the blue plug is what fits, which is 2.1mm centre pin size with a 5.5mm outer diameter. I don’t like the universal system in cases like this, if it comes undone you have to scrabble around with metres to be 100% sure you reconnect it correctly, so am going to get a fixed plug PSU…

I hope this will help someone else trying to source a supply in future.