Providing constant power using 2 PSUs

[Fritzz]

Here's what I am trying to do.

I would like to combine my gaming PC and WHS 2011 server into one case. 2 mobos, 2 PSU, etc. My goal is to have all my HDD/SSD stored in two of these Vantec Hot swappable bays. That's where my dilemma lies.

Gaming PC consists of 3 SSD, 1 for OS and 2 for data
WHS 2011 consists of 1 120GB SSD for OS and 5 2TB 7200 rpm Seagates for Data.

In total I have 9 drives and if I fill out the 2 Vantecs it would look like:

Vantec #1
Bay 01 - Desktop OS SSD
Bay 02 - Desktop Data SSD
Bay 03 - Desktop Data SSD
Bay 04 - Empty
Bay 05 - WHS OS SSD

Vantec #2
Bay 01 - WHS Data HDD
Bay 02 - WHS Data HDD
Bay 03 - WHS Data HDD
Bay 04 - WHS Data HDD
Bay 05 - WHS Data HDD

As you can see my WHS is the issue since I can't fit all 6 drives into one Vantec. Is there a way for me to supply constant power to the 4 SATA power inputs on the 2 Vantec Bay devices regardless of which PSU is on?

I cannot simply use some sort of splitter/reducer, this would just double the voltage and ruin my hard drives. My thought would be some sort of circuit board that would take power input from the two separate PSU, regulate the voltages and output 4 SATA power connections for both Vantecs. Does anyone know of anything that's currently made that would fill my need? About the only thing I have found is that add2psu which just acts like a remote turn on for a second or third PSU.

Thanks for looking!

 

[Fritzz]

No one?

 

[geok1ng]

the simple solution is to link both psus, alternatively you can power both systems with a single massive psu. but i still don't get the "it will double my voltages and ruin my hard drives". sata power is +12v and ground. 2x12v + 2xground is still only 12v, but you may experience some issues when powering up the second psu

 

[Nobu]

If you have double the amps going through the same path, you would get increased voltage (probably not double), but with two paths to ground voltages should remain about the same(because the excess current has somewhere else to go). (So, what geok1ng said)

Why not just run the two power supplies separately, just add a second power/reset button to the case? Edit: Sorry, misread.

 

[Jorona]

If the WHS 2011 server is always on, why not just use the power from it for all the drives?

 

[Fritzz]

I appreciate the replies, this is why I posted this here. I want to gather as much info as possible before I even attempt to do something like this.

the simple solution is to link both psus, alternatively you can power both systems with a single massive psu. but i still don't get the "it will double my voltages and ruin my hard drives". sata power is +12v and ground. 2x12v + 2xground is still only 12v, but you may experience some issues when powering up the second psu

Going back to my car stereo days, if you wire batteries in series then you get sum of the voltages with the same capacity, but if you wire the batteries in parallel you will have the same voltage and the capacity will be doubled. I assumed it would be the same, which is where the "it will double my voltages" statement came in. If I made sure to wire them in parallel then I should only get a 12v output, which a simple Y adapter should accomplish.

If you have double the amps going through the same path, you would get increased voltage (probably not double), but with two paths to ground voltages should remain about the same(because the excess current has somewhere else to go). (So, what geok1ng said)

Why not just run the two power supplies separately, just add a second power/reset button to the case?

I would hate to have excess voltage of any kind. Even though the Vantec Bay devices may be able to shed the extra voltage, just not sure I want to trust it to. The second power/reset doesn't solve the constant power I am trying to supply to the Vantec device that houses my two OS drives.

If the WHS 2011 server is always on, why not just use the power from it for all the drives?

After looking at my dilemma again. I could use the PSU for WHS to power the second Vantec because all that's in there is WHS drives. It's the first Vantec that is the issue since it will house the OS drives for both machines. So if I power both Vantecs with the WHS PSU, and for whatever reason the WHS restarts or shuts down, then I lose the OS and Data drives for my main PC. Which is why I am trying to figure out a way to supply constant 12v power to the first Vantec, regardless of which PSU is on/off/restarted.


Looks like at this point I need to get some old crappy PSUs and do some testing. Thanks for the input!!

 

[Tsumi]

The power supplies are designed to output 12v, that's it. The connectors on the Vantec will be in parallel, so the same voltage will be supplied.

What will happen, however, is that there will be variations in PSU voltage. One PSU will have a slightly higher voltage than the other, and will be sending current to the other PSU due to the voltage variation. In most cases it won't be a cause for concern, it'll probably just result in lower efficiency.

If you want constant power to the first Vantec, the best thing to do would be to get a third power supply for it and have it always on.

 

[Fritzz]

What will happen, however, is that there will be variations in PSU voltage. One PSU will have a slightly higher voltage than the other, and will be sending current to the other PSU due to the voltage variation. In most cases it won't be a cause for concern, it'll probably just result in lower efficiency.

Assuming this would go to the other PSU via the ground and just be sent off as wasted energy?

If you want constant power to the first Vantec, the best thing to do would be to get a third power supply for it and have it always on.

As much as I don't think I want to do this, it's probably the safest. Something like This should fit the bill.

 

[Netwerkz101]

No one?

I needed a visual aid i think ... but probably misunderstanding your post...anyhow:.

When i first read this thread .. i saw three issues:
1. Mounting 2 motherboards in a case designed for 1.
- Easy to overcome for any kid that has used an Erector Set - space permitting
- Or i misunderstood the goal.

2. Powering the second motherboard:
- Easy enough to add second PSU (you already mentioned this)
- Or maybe I misunderstood the goal.

3. Drive Placement
- Instead of trying to get all drives in the two Vantec units,
Place the 3.5" drives in the Vantecs and place the 2.5" drives in a 4 (or 6) bay mobile rack


Assuming you are placing in the K12 case in your sig?

 

[Netwerkz101]

Oh .. and unless you need hot swap for the SSDs, you can velcro them where space is available in the case.

 

[Fritzz]

I needed a visual aid i think ... but probably misunderstanding your post...anyhow:.

When i first read this thread .. i saw three issues:
1. Mounting 2 motherboards in a case designed for 1.
- Easy to overcome for any kid that has used an Erector Set - space permitting
- Or i misunderstood the goal.

Yep the goal is to combine my main rig(in my sig) and my WHS(sig is the old version I really should update that) into one case. The one I am looking at is Fractal Node 804. Main PC would go where it's supposed to and the mini-itx board for my WHS would go in bay behind.

2. Powering the second motherboard:
- Easy enough to add second PSU (you already mentioned this)
- Or maybe I misunderstood the goal.

Yep 2 psus, well maybe 3 at this point.

3. Drive Placement
- Instead of trying to get all drives in the two Vantec units,
Place the 3.5" drives in the Vantecs and place the 2.5" drives in a 4 (or 6) bay mobile rack

I still have the same problem as before. With all the SSDs in one enclosure, I need to supply constant power to that enclose since it will house the OS drives for both machines.

Assuming you are placing in the K12 case in your sig?

Nope, like I said above thinking about using the Fractal Node 804. My server is currently in a Fractal Node 304 and main rig is in a Fractal Arc Midi. I would like to use the Vantec bays for a clean look. Similar to what I did with my Node 304:

 

[veryrarium]

That's a really nice case mod, wow. Are you sure you want to switch to 804?

 

[Fritzz]

That's a really nice case mod, wow. Are you sure you want to switch to 804?

Thanks! Feeling the waters out to see if I even want to do it. As with most of the modders on [H] there's always another project to be had.