Standby or Hibernate w/ nlited windows

**IntellaWorks** · 02-19-2005, 01:17 PM

Alright here's my situation I'd like to throw out there so maybe I can get some other good thoughts back.

I've nlited my windows os in my car pc, which takes about 12 seconds to cold boot to the shell. I've got a carnetix 1260 dc/dc reg % shutdown controller. I'm storring my OS on a Compact flash card on the IDE bus. My OS is about 540MB on the CF card w/o hibernation, I've got 256MB of ram (32 is video) so with hibernation enabled my OS could be about 800MB, My CF card is a 1GB. Now that you know my configuration lets get down to the situation.

I'm trying to decide how my machine is going to shutdown when I turn my car off. I haven't had my PC in my car for a while but I've been thinking to myself how many times a day I get in and out of the car and do I really want to wait 10-15 seconds when I start my car back up for the machine to cold boot.

For those of you who don't know abou tthe carnetix 1260, its an intelligant shutdown controller that has a few cool shutdown features... here they are...

1 - when ignition is shut off it can wait 6 second or 15 minutes to shut the machine down

2 - Keep the machine in hibernation

3 - Keep the machine in standby while monitoring your vehicle's battery, if the voltage drops below 10.5v for more than 10 seconds it stops power going from the PC.

Here is my delima, I've tested hibernation which basically saves the system state on the harddrive. When I power it back up it takes about 7-9 seconds, which to me isn't worth it because my machine cold boots in 12.

I'm basically thinking about 15 minute shutdown delay or standby but I'm mainly stuck in deciding which option to choose.

15 minute shutdown delay is great because if I get gas or something I wont have to worry about the machine restarting, but I think that the constant draw off the battery with the PC running at full power for 15 minutes every time I turn the key off is a lot of strain on the vehicle's battery and really it's unneeded because sometimes I'm shutting my vehicle off for the night. I just don't think I'm ready to by a deep cycle battery because my truck is an 04'

The standby feature is attractive because my pc immediatly stands by, and takes about 2-4 seconds to come back to life. This would be great for times when I'm away from my vehicle for more than 15 minutes. Also my pc only has the CPU fan, Case Fans and RAM powered. So It's less of a draw on my battery. But here's where I'm worried, what if it's below 0 (I live in NH) and my battery gets down to 10.5 volts, shuts the machine off then 2 minutes later I get in to start my truck... will this be enough to kick my car over ?? Also another concern is that I've tried testing and I feel pretty confident about is that if my machine does go into a standby mode and I leave my car Carnetix documentation says there's a possibility of it catching on fire because the internal fan stops. My case fans are about 3 inches away and would be on if the machine didn't shut down so I don't think it would get hot enough to burn but possibly fry the PCB board... I'm also thinking about really hot days in the summer (90 + degrees) I mean I'd add a fan... but if I'm going to utilize this standby process adding fans would draw more from my battery !!!

So I'm looking for other poeples opinions what would you guys decide to do ?? Thanks for the responses...

Randy

**KyferEz** · 02-19-2005, 01:38 PM

Randy, you could use a temperature controlled circuit to start a fan if it becomes too hot. Want one? Take me a few days to do

Does the carnetix not allow you to adjust the low voltage level? Humm, our SDC does, but I doubt you want to do all that just to get an adjustable low v level. We could do a circuit that allows you that option along with the temp monitor for fan control.

I'm not sure how much it would cost off-hand. Quality linear temperature sensors aren't cheap, even at large quantity (which is why mp Pro Power Controller so much more). But the rest won't be too much.

KyferEz