what DC board in your current case?
Guys im sure you will be able to answer this with ease,
I have a ITX board and will be running 2 2.5" drives off it, I already have the laptop style power supply for the board as it came with the case I bought.
Ideally I want the comp to boot up once the car is running ie using a ITPS or a Jeff Mucha controller, which one is best ? and by using one do i no longer need the DC board that is in my current case, ie do these boards apply the power directly to the motherboard.
Cheers, Im sure ill be doing some major posting on here soon hehe.
what DC board in your current case?
You will still need the DC-DC PSU if you're using the ITPS, and i'm pretty certain you will need it with the JMSDC as well
Morex 55W PSU and DC-DC Converter Kit
Ideal for anyone wanting to create their own Mini-ITX projects as seen on these pages. These are exactly the same 55W PSUs and DC-DC Converters found in the Cubid 2677R/2688R cases, now available separately. The DC-DC Converter measures only 160 x 45mm, and can be fitted in the wee-est of crannies. Comes with 110-230V PSU, DC-DC Converter board and cables, power cable and plug.
Note: These PSUs are only 55W, (please remember what they were originally designed for - we recommend a 5400RPM or laptop drive and slimline optical) - unsuitable for use with full size CDROM drives!
ALL HELP APPRECIATED
I'm using one of those Currently wired directly to the battery...and am running a 3.5" desktop HDD off it too...! However it's not guaranteed that i won't destroy my hard drive doing that And, as always...YMMV (your milage may vary) if you try to copy me
I have the Casetronics C134 case which contains essentially the same power supply. I couldn't tolerate the AC/DC conversion, so I bought RadioShack DC/DC converter and wired it thru the ITPS (only for shutdown). Here's a picutre of what I did (My Power Supply ). It is ONE way of supplying power. Keep searching this forum. There are several other good approaches as well.
the quest continues, ill keep u updated :-)
MikeH, could you explain why the need of the notebook PC DC to DC adapter?
Is that to regulate voltage? Would using a regulator work as an alternative?
Does it function during cranking?
I have the Casetronics C134 case with an M10000 motherboard, which is very tightly packed. The case came with an internal Morex-like internal power supply which takes +12v in from an external AC/DC converter (also supplied with the case). I didn't want the AC/DC setup because of the complexity and noise generated by the DC/AC inverter that was required to drive it. So I needed a source of +12v to take the place of the original external "brick". After looking into whether or not I could directly connect to the car battery/alternator for my 12v supply and get rid of the the brick, I found out that the internal case PSU did not regulate the incoming +12 line. It is fed directly to the motherboard. This is not desireable IF the incoming 12v line is used by the mobo without further regulation. (fyi, the jury is still out as to whether anything on the motherboard actually uses this 12v directly, and hence, would be damaged by any overvoltage coming from the car battery system). Also, the Casetronic website FAQ states that the incoming 12v tolerance is +/-5% (or 11.4v to 12.6v).MikeH, could you explain why the need of the notebook PC DC to DC adapter?
I found the Radio Shack Laptop Adapter which meets this spec and can take an input from 11v to 16v without shutting down. It can handle 60watts, which for my setup, is OK (60w=12@5A, my system needs 3.4A max).
I feed the adapter into the ITPS, which I use as a startup/shutdown controller since I have bypassed it's internal 12v linear (inefficient) regulator. The reason I'm not using the on-board ITPS regulator is that it needs a minimum of 13.3v at it's input to provide a regulated 12v output. When the engine is off, my battery sits around 12v, which means the ITPS would be outputting approx. 10.7v, which would crash the system.
I'm going to try to implement Ricky's idea with the backup SLA battery to prevent PC crashing during cranking. It sounds like a good solution. I'll let you know if it works in my system.
Anyway, a long-winded answer, but it's probably one of the toughest design challenges in the carpc system.
Let me know if you've got any other questions.
A great wealth of information, MikeH. Thanks.
That just further strengthens and confirms what I learned here.