Regulated 12 Volt DC power

DavidOH

Since I am using a PC I want to keep it from being under/over voltage.
( Low Power PC Project: http://forum.solar-electric.com/showthread.php?10467-Low-Power-PC )
I am thinking of adding something to regulate it:
150W 8A DC 8-32V to 9-46V 12v 24v 36 step up BOOST converter pc car power Supply
http://www.ebay.com/itm/400557877161

Am I going overkill with this? :
Samlex IDC-200A-12 Fully Isolated Converter DC-DC Fully Isolated
http://www.amazon.com/Samlex-IDC-200A-12-Fully-Isolated-Converter/dp/B0073HP7S8/ref=sr_1_fkmr2_2?ie=UTF8&qid=1383187861&sr=8-2-fkmr2&keywords=SAMLEX+IDC-200A-12+200W

*** Is such a thing necessary? *** If so what are you using? *** What would you recommend for a 12 volt system? ***

I am on a 500 watt system. The computer may use 31 watts.
A small refrigerator run separately on an inverter will use about 80 watts with an 800 watt surge.
http://forum.solar-electric.com/showthread.php?10461-My-Solar-Project

My recent build.
Tested using about 31 watts. Micro PC AND the 21" monitor.
The PC alone uses about 17 watts. On standby (or OFF) uses about 3.
Motherboard is Intel Atom Dual-Core D525.
http://tinyurl.com/6m9g29s
Intel Atom Dual-Core D525/Intel NM10/DDR3/A&V&GbE/Mini-ITX Motherboard BOXD525MW

I found the Samsung LED monitor listed above on sale for $140 with FREE shipping.
The case is (IMO) the ONLY micro PC case:
http://tinyurl.com/7ycfnp9
M350 Universal Mini-ITX PC enclosure PicoPSU compatible

The picoPSU Power supply is in and this thing is totally silent.
I used an OCZ Solid State Drive. This should be enough for my needs.
As you can see the size is about 8.5 inches deep by 7.5 wide and 2.5 tall.

mike95490

Re: Regulated 12 Volt DC power

the 150 watt car regulator, is a tad over powered for a 32 watt PC. You will likely waste 50w in the DC-DC process. Something in the 50W ballpark would be better. Does the PC have a power supply unit in it? The amazon case page, showed a "also bought" a 12vPSU.

RandomJoe

Re: Regulated 12 Volt DC power

I'd just get a wide-input PicoPSU. They make models that have various input ranges. I have one that'll operate just fine on 8V-20V or something ilke that, so that if I use it in the car it will even handle the low voltage from the car starting.

For example:
http://www.mini-box.com/M3-ATX-DC-DC-ATX-Automotive-Computer-car-PC-Power-Supply?sc=8&category=981
6V-24V input.

DavidOH

Re: Regulated 12 Volt DC power

Good point Joe. I should have thought of that BEFORE I built the PC. It it done. That PS would not have cost much more than the one I have.
I may upgrade to an i5 PC that would use slightly more electricity.
I selected the regulator in the 120-150 watt range because the PC could theoretically use as much as 90 watts. In addition there may be lights and fans on the same regulator circuit.
Thanks for the input.

niel

Re: Regulated 12 Volt DC power

if memory serves an i5 desktop 4th gen cpu will draw in the neighborhood of about 84w and that's only the cpu. my i5 draws about 77w being an older model i5. not sure which generation you are going with, but here is the 3rd gen model i have and the comparison to the newer 4th gen. it is a really fast and capable cpu compared to my older 2.8ghz p4 hyperthreading and even my old amd 2ghz dual processor with my 3570k literally blowing them out of the water.
http://www.intel.com/content/www/us/en/processor-comparison/comparison-chart.html

if you're talking mobile model i5s then you can use this link to look up the various model cpus you'd like to consider.
http://www.intel.com/content/www/us/en/processor-comparison/compare-intel-processors.html

DavidOH

Re: Regulated 12 Volt DC power

DavidOH wrote: »

Since I am using a PC I want to keep it from being under/over voltage.

You may have missed the point. I thought it was clear enough.
The PC is already built.
I'm asking for opinions on IF there should be a regulator on the power circuit.
Did you include one for your home?

I did purchase the one on eBay. About $9 for a 120 watt maximum circuit. I'll need a space in the fuse box for it.

niel

Re: Regulated 12 Volt DC power

so you didn't say this?

"I may upgrade to an i5 PC that would use slightly more electricity."

i wasn't referencing how you will power it, but rather what the cpu draw is.

mike95490

Re: Regulated 12 Volt DC power

DavidOH wrote: »

...
I did purchase the one on eBay. About $9 for a 120 watt maximum circuit. I'll need a space in the fuse box for it.

I think you should have a separate DC box for it.

DavidOH

Re: Regulated 12 Volt DC power

Yes, it will have it's own box, but since it is so small ( only a couple inches ) it will fit inside the fuse box which is about 8x9 inches.

"I MAY upgrade"..... Whatever I MAY upgrade to won't use much more that the one I am powering now.

The entire point of this thread has not been addressed yet:

*** - Did you include one for your home? - ***

" *** Is such a thing necessary? *** If so what are you using? *** What would you recommend for a 12 volt system? *** "

RandomJoe

Re: Regulated 12 Volt DC power

When I was running a 12V system, no I didn't include a regulator for 12V items. I had the entire ham bench attached directly to the bank, ran a 12V line to my cable modem, wireless AP and router, had a "car computer" powered directly off 12V, and occasionally ran some 12V fluorescent lights.

With caveats.

First, I rarely equalized and then only manually. I also wasn't as aggressive about it as I've seen some people describe (kept the voltage down a bit). I turned off most items when equalizing.

The car computer had the previously mentioned wide-input PSU.

The networking gear was Linksys kit, with 12VDC wall-warts. They were apparently transformer design, and their voltage was not highly regulated. No-load was closer to 17V. Even powering the equipment they tended to be 14-15V so I wasn't concerned about running these items straight off the bank. I have since replaced them all with new gear, so would have to rethink that. (Some of it doesn't use 12VDC anyway so…)

Not sure what I'd recommend to someone else! I was willing to take the chance with my Linksys gear primarily because it was all pretty old kit anyway. If I burned something up it wasn't a great loss. I was less eager to run new items straight off the bank, and wound up converting to a 48V system when I upgraded so never went any farther with it.

DavidOH

Re: Regulated 12 Volt DC power

Thanks R Joe. That's what I was thinking. Most of the things will easily accept a wide range of voltage input. I'll keep this thing for the 9v items.