Power Supply Question

[n1ist]

Looking at the pixelnet hub picture in the wiki, it uses both the 24-pin ATX connector and up to three hard-drive connectors.

/mike

[CaptKirk]

Yes, that is what got me thinking.  THAT potentially causes rail tieing issue right there if power is taken from both the ATX and the HDD power as those ARE different rails in a split rail system.

Also, different HDD leads (on different wires) can be on different rails also.   So if that is OK somehow (avoids the differential regulation issue) ,  then why is another tieing situation NOT ok?  I am not convinced this has been thought through all the way and either tieing IS ok, or there needs to be tighter restrictions on the ATX used to AVOID tieing and the "bad things"!!   If tieing is bad, then split rail power supplies cannot be used, but if that is ok then tieing should be OK other ways as well.  I'm hoping the later is correct but right now the former looks to be the rule and some people may have the wrong PS and are risking issues by unintentionally tieing the 12V rails via the HDD power cables.

RJ am I wrong and we need to warn people away from split rail supplies, or was I right and you are tieing via the HDD connectors but did not realize it?

<EDIT:  I am wrong as pointed out below (it is in the WIKI now) but we do need to be sure everyone avoids split 12v rail ATX power supplies- I am thinking of taking pictures of labels of some of the many ATX power supplies to which I have access as a guide (this is goood, this is baaaad) if that is OK with everyone.>

[Trepidati0n]

RJ has specified a single rail supply...in the wiki.  It is at the bottom of page one on the Smart String Power Requirements file.  This has been a point since DAY 1.  The reason he put all those connectors there is for having enough power without damaging the wire.  I have no idea why you are trying to make a mountain out of a pile of which is this dead horse.

EDIT: Here is the rating table when doing 12V work.  Very similar style (insulation type) wire is used for PC's.

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[keitha43]

RJ designed this to work with either a computer power supply or a non computer power supply but not both at the same time. Obviously you should go with the recommendations of the board designer (RJ). I personally don't want to risk damaging any component in my display. If RJ thought using multi rail power supplies were okay he would have said so. Since he said the exact opposite I don't have to care what the reasoning is. His word is good enough for me.

[TheBanker]

Looking at the pixelnet hub picture in the wiki, it uses both the 24-pin ATX connector and up to three hard-drive connectors.

/mike

Does this mean you can use all these connectors from one power supply?  Or do you use different power supplies?

[CaptKirk]

RJ has specified a single rail supply...in the wiki.  It is at the bottom of page one on the Smart String Power Requirements file.  This has been a point since DAY 1.  The reason he put all those connectors there is for having enough power without damaging the wire.  I have no idea why you are trying to make a mountain out of a pile of which is this dead horse.

You are correct, looking now in the Wiki, I see that information.  I wish someone had pointed that out and repeated it here earlier! The last time I looked in there, it was all dummy entries or restricted to SYSOP group (like the manuals are now).  That is (mostly) my mistake that I missed it buried in the incomplete area on the wiki.   I wonder how many others are getting split rail power supplies as most of the more "affordable" high power ones are split now due to ATX12V standard?  I think that needs to be clearer.  That is the pile of dead horse here...

EDIT: Here is the rating table when doing 12V work.  Very similar style (insulation type) wire is used for PC's.
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That is a nice chart.  I got my info here: You are not allowed to view links. Register or Login but I wonder if they mixed up 120Vac with 12Vdc use?

Thanks for the info (finally).

[chrisatpsu]

single rail power supply, then hook up the 24pin atx connector,
hook up a hdd 4 pin molex connector from a set of one string coming from the SAME power supply
repeat for the other strings of hdd connectors coming out of the SAME power supply
any extra hdd connectors on the hub, populate with any available spare 4pin molex hdd connector from SAME power supply.

this helps distribute the power across the conducters providing 12v power from a SINGLE rail power supply without issues.

if your display is running a high number of nodes or modules, considering breaking up to two or more hubs, set to use the same pixelnet universe...

Is there really any more questions after that?

[CaptKirk]

I'm good now!!  SINGLE RAIL is key!!!  AMEN!!!

[taybrynn]

Good deal going at NEWEGG today on an Antec (80 Plus rated) 30amp single rail 12V ATX power supply for $25 with free shipping.

These won't last, I predict.  There may not work for you if your putting a lot on your SS hub, but if your good for at least 6 items at 4a each and
thats keeping it under 80% of capacity.
 
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[Pete]

Thanks for the information.

I just ordered 2.   Just need 2 more power supplies at about 40a each.

[chrisatpsu]

holy crap! 2 - 30's AND 2 - 40's? 

you might as well tap into your nearest nuclear power plant!

j/k

[taybrynn]

looks like that deal is over already. 

[taybrynn]

70A MODULAR PS for $120 after $15 rebate with free shipping ... 80 plus silver certified, modular (connect the cords you want) ...

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40A PS for $37 after $20 rebate with free shipping ... good reviews/brand

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both deals dead now

[therealbigjim]

The new egg shell shocker link took me to a blue tooth router combo deal.

[chrisatpsu]

the links dont last long