Using power supply without computer

[Meathead]

So I'm using my beastly backup PSU (Corsair HX850W) for some side projects and I was wondering if anyone has had any experience doing so.

I'm using it currently to power a standalone water-cooling system.

I am going to use it to power my electronic RC lipo charger.

After doing some reading, I've read a lot of users needed resistors to put loads on the 5V rail to get the PSU to deliver the specs of the 12V rail to use for an RC charger power supply. This is the first I'm hearing about this being done so I wanted to see if anyone here knows whats up or knows more about PSU's than I do.

 

[ATMINSIDE]

I used a computer power supply as an emergency supply for my senior design project.
Tapped in to the +12V and +5V, worked perfectly.

Do you know what amperage the charger takes?

 

[Meathead]

I used a computer power supply as an emergency supply for my senior design project.
Tapped in to the +12V and +5V, worked perfectly.

Do you know what amperage the charger takes?

The charger I'm looking at is 30A so I'm sure it will be more than able to handle it. Since you used both the 5V rail and the 12V, I can't really use that to answer my question though bummer haha.

The myth I'm trying to confirm/debunk is needing a load on the 5V raid to get all of the internal electronic monitoring on the 12V rail to come on properly or something. Not sure I fully understand or if they fully understand what they are talking about but it looks like a few of them were measuring well below 12V on the 12V rail and loading the 5V fixed it. On some, they said the 12V rail was not being regulated properly by the internals

 

[ATMINSIDE]

We were also pulling a scarce amount of wattage. Probably 15W peak, it only had to drive an Arduino w/ touchscreen and a few servo and stepper motors.

Just letting you know that I had used one successfully outside of computer parts

Since that's a fairly modern PSU, I doubt you'll need much (if any) 5V load.
Computers don't load up the 5V rail like they did ~10 years ago.

 

[Meathead]

We were also pulling a scarce amount of wattage. Probably 15W peak, it only had to drive an Arduino w/ touchscreen and a few servo and stepper motors.

Just letting you know that I had used one successfully outside of computer parts

Since that's a fairly modern PSU, I doubt you'll need much (if any) 5V load.
Computers don't load up the 5V rail like they did ~10 years ago.

Ah haha gotcha. That's why I'm getting into quad's with my senior design coming up soon enough. Although making a Tesla coil is something that would be badass too.

And I agree with your last statement. I guess I will just try it out and see what happens. Just don't want to ruin my beauty haha

 

[ATMINSIDE]

I was using an old Appro 1U server PSU that I didn't care about anyway

Just had to get something, we had the cheap-o laptop style PSU that the school bought burn up LOL!

 

[Bobnova]

If it's a DC-DC 5v/3.3v PSU or an independently regulated PSU, you don't need to do anything special at all.

Is it this specific unit? http://www.hardocp.com/article/2012/08/22/corsair_hx850_gold_power_supply_review/3

If so, you're all set and don't have to worry about load balancing.
If it's group regulated, you'll need some resistors on the 5V rail.

 

[Meathead]

If it's a DC-DC 5v/3.3v PSU or an independently regulated PSU, you don't need to do anything special at all.

Is it this specific unit? http://www.hardocp.com/article/2012/08/22/corsair_hx850_gold_power_supply_review/3

If so, you're all set and don't have to worry about load balancing.
If it's group regulated, you'll need some resistors on the 5V rail.

Unfortunately, it is the previous version of that same PSU.

I think its this one http://www.corsair.com/en-us/profes...us-silver-certified-modular-power-supply.html

Silver instead of gold rated.

 

[Bobnova]

You're in luck, that one is DC-DC as well: http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=153

 

[Meathead]

You're in luck, that one is DC-DC as well: http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=153

Damnit how did you find that. I went to there and it gave me a link to hardware canucks review instead of his review haha. Thanks Ed.

 

[Bobnova]

Skills?

Actually, google, searched for corsair hx850 -gold
The -gold got rid of all the gold rated units, and left the JG review fairly close to the top of the google heap.
It probably also marks me as someone from the dark ages of internet searching when you had to specific AND, OR, +, -, etc. manually.

 

[Meathead]

Skills?

Actually, google, searched for corsair hx850 -gold
The -gold got rid of all the gold rated units, and left the JG review fairly close to the top of the google heap.
It probably also marks me as someone from the dark ages of internet searching when you had to specific AND, OR, +, -, etc. manually.

Ah I used his site search. Never ever works as good as old fashioned google. I did not know about the -gold either wow...

 

[Bobnova]

Yeah! You can specify that results can't contain words, or that the absolutely must have a word (that's +).
It changes eeeevvvverything.

 

[Meathead]

You're in luck, that one is DC-DC as well: http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story&reid=153

Do you mind explaining this? I think the review states that the box says DC-DC but oklahomawolf says something about that being untrue and said he would verify it later on in the review on page 4 once he opened the unit and never did.

 

[Bobnova]

My read on that is that the box says "All rails are DC-DC", he's pointing out that the 12V rail can't be, as some rail has to be AC-DC.
The 12V rail is pretty much always AC-DC, then 5v, 3.3v and -12v either AC-DC, coming from the primary side, or DC-DC coming from the 12v rail.

In that unit's case, it's an AC-DC 12V (normal, good, fine), and DC-DC 5V/3.3V.

 

[caddi daddi]

you can use psus for lots of things, I ofeten piggyback two for the same rig it works just fine.

 

[Meathead]

My read on that is that the box says "All rails are DC-DC", he's pointing out that the 12V rail can't be, as some rail has to be AC-DC.
The 12V rail is pretty much always AC-DC, then 5v, 3.3v and -12v either AC-DC, coming from the primary side, or DC-DC coming from the 12v rail.

In that unit's case, it's an AC-DC 12V (normal, good, fine), and DC-DC 5V/3.3V.

Would it ever be advantageous to do AC-DC, say 120 to some voltage higher than 12V and then DC-DC for all 3 rails. Similar to how class A and class C amps are used together to hit certain power requirements with low distortion.

Only reason I ask is I would consider that DC-DC for all 3 rails and their claim reasonable if they did it that way.

 

[Bobnova]

I could see it being advantageous if you were after really low ripple levels, though rather than DC-DC you'd probably be using linear regulators. I don't know much about the audio world, or other worlds that require staggeringly low ripple levels like that.

Another place that comes to mind would be going from really high voltage, say something where you needed to have 12VDC and the rest of everything ran 4000VAC.

Pretty specific situations. Laptops qualify, they typically have a power brick that does AC-19.2VDC and then 19.2 to 12V/5V/3.3V internally.

 

[Meathead]

I could see it being advantageous if you were after really low ripple levels, though rather than DC-DC you'd probably be using linear regulators. I don't know much about the audio world, or other worlds that require staggeringly low ripple levels like that.

Another place that comes to mind would be going from really high voltage, say something where you needed to have 12VDC and the rest of everything ran 4000VAC.

Pretty specific situations. Laptops qualify, they typically have a power brick that does AC-19.2VDC and then 19.2 to 12V/5V/3.3V internally.

Hmm this may or may not be it but is that what causes the load for laptops to seem more "linear"? That's from the power companies prospective and I think is not required in the US but is still used in power packs because its required in EU and other places.

 

[Bobnova]

The power factor correction I think you're thinking of is what the APFC bits in all modern PSUs do. It's unrelated to the 19.2v output voltage from the pack.