n00b question alert! How to power a min-ITX system?

RDaneel,

I'm currently in the process of trying to put a DC/AC inverter in my car to power my M10000 in a casetronics C134 case. The inverter works fine, but puts a huge amount of noise on my audio lines. So much so that it is basically un-useable for playing MP3's. I bought a cheapy inverter ($30 for a 120W inverter @ Wallymart). I guess I got what I paid for. I'm going to try to return it for the more expensive version ($60 150W) which touted it's filtered sign wave output. My guess is that my el-cheapo is putting out some sort of very noisy square wave that's killing my audio.

I'm not familiar with the various "ATX plug-in" on-board power supplies (like the PW-70a), but my guess is that they won't fit in my C134 case (very tight). If you are using the C137, just check to make sure there is room above the supply. In the case of the C134, there's no room above the power supply. In fact, it's packed so tight, there's no room for ANYTHING else.

I'd check out some of the technical specs on the Opus 150W supply (www.opussolutions.com). His specs tell the story of what you should look out for when trying to select a power source for an automotive application.

Good luck n00b. This stuff is really fun.

Thanks, Mike! I'm trying to be less of a n00b every day... I have pretty decent experience with "regular" and HTPCs, but this is my first car project...

The Opus seems like a good way to go, or the ITPS/PW-70 combo. Both would be a bit of a waste in the C137 case, as you already get a PSU in those systems. Still, it would be nice to have the devices already safely mounted...

You know what, I have a hard time with the term "noob", because I keep getting images of little kids typing one-fingered on their keyboards everytime I hear it. EVERYONE is a noob at something. No matter what anyone says, there is SOMETHING they don't know. I know lawyers that could whoop my *** in legal issues any day of the week, but are completely green when it comes to something as simple as retrieving their email.

I hope people aren't getting tired of the "n00bs" showing up here. I think it's exciting that our hobby is reaching more and more people, and I can promise that I will do whatever I can to give any new guy (or gal) a hand to get their foray into mobile electronics off the ground and running.

I say "welcome all NEWBIES!"

RD.

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Both would be a bit of a waste in the C137 case, as you already get a PSU in those systems

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Yeah, but, according to Casetronics FAQ's...

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Which system can I power directly from the 12VDC source in my car?
We have a few models that use a DC to DC converter inside the chassis, however, we do not recommend customers to power their system directly from a car battery without regulating it first. The input for the converter is 12VDC +/-5% tolerance.

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This means you either have to replace the one supplied by Casetronics, or pre-regulate to 12V+/-5%. It's unfortunate that they don't sell the case without the PSU.

Opus seems to have thought thru the requirements in great detail. They've had some unfortunate problems tho, with their 90W unit. Hopefully they have fixed that since it looks like a nice replacement for my C134 PSU.

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Originally Posted by MikeH

I'm not familiar with the various "ATX plug-in" on-board power supplies (like the PW-70a), but my guess is that they won't fit in my C134 case (very tight).

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look on mini-box.com for a pic of the pw-70(a) ... it's very small and plugs straight into the mobo.

if you have the skills or the ability to go dc-dc you should always choose that over an inverter for the exact reason you stated ... noise.

Addig to the n00b thread;

Could someone kindly go over regulators? What is available and if one should be used with the Opus?

Speaking of the Opus; why would you choose the 90W over the 150W version?

Thanks,

Alric

regulators do as the name suggests and 'regulates' power by providing a steady output from a not so steady input. generally speaking, regulators need a higher voltage on the input than you expect to get out of it.

as far as what is available ... there's a bunch of different regulators depending on what you want to do with it. For car usage, a lot of peopl are using the LM1084IT-12 ... it's is a 12v version of the adjustable 1084 regulator.

The problem with using these regulators in cars is, generally speaking, most regulators have a very low current tolerance. the 1084 allows 5a of current, and that's the best i've found for 12v. This means your circuit will max out at 60w.

regarding the opus ... i THINK it regulates itself and there is no need for external regulation. don't take my word for it tho.

if you have the $$ for the 150w get it. 90w is probably plenty but if you can get the extra power why not B)