in-vehicle PC build - advice needed

[blue-moves]

Hi,
I'm planning to build my own in-vehicle music production workstation in my motorhome so that I can compose, record, edit and mix music while I travel..
So, OK - 2 principle requirements are nonnegotiable..
1) It MUST run on 12volts (natively, no step-ups or downs..!) and
2) It must have super LOW power consumption (at least on idle) as I usually work about 10 hours a day and would like to not stress my leisure batteries.
Can anyone tell me what it is that enables some industrial computer manufacturers to offer PCs (running Intel i7s, for instance) that idle at 5-10 watts when 'normal' domestic PCs (running similar chips) seem to generally idle at 80-200 watts?
Please!!?? This totally mystifies me!
The other thing I hope to find out before I start is: what is it about some computers that enables them to run directly from 12v when most domestic laptops for instance require 19v?
Please only reply if you know what you're talking about and can answer my questions.
Thank you.

 

[USAFRet]

High end laptop(s) and a good voltage converter.

Any desktop level solution fails on multiple points.

 

[blue-moves]

Did you read the part in my post where I said "Please only reply if you know what you're talking about and can answer my questions."??
Here's one of the PCs I can't afford (hence why I'd like to build my own..) - This one idles at <9 watts and runs on 12v directly.
http://www.in-carpc.co.uk/products/view/cq50-fanless-vehicle-pc

 

[Gadhar]

He does know what he is talking about and gave you a simple answer to your question. No need to be rude to someone trying to help. There was no budget listed to help give us an idea of what direction to point you. Good luck in your hunt.

 

[USAFRet]

Well..since you did not specify a budget until now...a good laptop would have been a good solution. But that would be out of your price range.

Now that we have an upper range of price (£852.00), maybe some better solutions will appear.
Of course, what software you'll be using also has an impact on the parts list.

 

[InvalidError]

Yup, get a laptop. That's the only way you're going to have a whole system under 20W under light loads.

You don't want to run your laptop from straight 12V that gets charging from a vehicle alternator since alternators can generate massive voltage spikes when "load dumps" (large load disconnects) occur and this could fry the laptop's power management circuits. You want either a DC-DC converter capable of handling 100V input spikes, a voltage limiter circuit to clip the pass-through voltage or heavy filtering to block noise and spikes.

As for why some laptops have 12V or 19V, that's usually chosen to be higher than the battery voltage so the transition between battery and external power can be handled by plain old diodes. A 12V laptop will have a 2S or 3S battery pack while a 19V laptop will be either 3S or 4S.

 

[ko888]

Did you read the part in my post where I said "Please only reply if you know what you're talking about and can answer my questions."??
Here's one of the PCs I can't afford (hence why I'd like to build my own..) - This one idles at <9 watts and runs on 12v directly.
http://www.in-carpc.co.uk/products/view/cq50-fanless-vehicle-pc

That unit uses an Intel Core i7-6600U, 2.6 GHz, 15 Watt TDP laptop CPU. It only has 2 cores and 4 threads. It's very weak when compared to a desktop CPU like the Intel Core i7-6700K, 4.0GHz, 91 Watt TDP that has 4-cores and 8-threads.

Weak CPUs just don't require as much power to run.

 

[blue-moves]

There are two questions in my post:
1) "Can anyone tell me what it is that enables some industrial computer manufacturers to build PCs that idle at 5-10 watts when 'normal' domestic PCs (running similar chips) seem generally to idle at 80-200 watts" and
2) "what is it about some computers that enables them to run directly from 12v when most domestic laptops for instance require 19v?"
Please only reply if you know the answers to THESE questions.
Thanks.

 

[USAFRet]

There are two questions in my post:
1) "Can anyone tell me what it is that enables some industrial computer manufacturers to build PCs that idle at 5-10 watts when 'normal' domestic PCs (running similar chips) seem generally to idle at 80-200 watts" and
2) "what is it about some computers that enables them to run directly from 12v when most domestic laptops for instance require 19v?"
Please only reply if you know the answers to THESE questions.
Thanks.

1. They take laptop level parts and build it into a small rectangular case, with a custom motherboard.
Built to a specific purpose, and not including all the other parts a traditional universal use desktop might have.

2. One of my laptops has a 12v brick (older low end Toshiba), another has a 19.2v (newer HP i5).
Another one runs and recharges directly off 5v USB.
Different power requirements.

 

[InvalidError]

There are two questions in my post:
1) "Can anyone tell me what it is that enables some industrial computer manufacturers to build PCs that idle at 5-10 watts when 'normal' domestic PCs (running similar chips) seem generally to idle at 80-200 watts" and
2) "what is it about some computers that enables them to run directly from 12v when most domestic laptops for instance require 19v?"
Please only reply if you know the answers to THESE questions.
Thanks.

The first answer is simple: laptop parts, not desktop parts. The i7-6600U is an ultra-low-power 2C4T part closer to a desktop i3 than an i7.

The second answer: that computer does not "run directly from 12V", it has a custom PSU ruggedized for vehicle use which uses DC-DC converters to convert the 9-36V vehicle voltage to the 3.3/5/12V required by the various computer parts. A laptop does the same thing with its 7-17V battery and 12-19V external adapter voltages.