M1-ATX & external switch

**simor** · 09-08-2006, 08:54 PM

Hi,
I would like to add an external switch to my M1/Voom pc to control the auto-powering up/down. By this I mean a 2 position switch:
ON: auto powering is working accordding to the ignition signal
OFF: auto powering is off and/or no power gets to my pc

I thought I'll put the switch on the ignition line but then the pc will drain my battery slowly (i read it takes very little current even when its off) - ps. how much is it / how long will a car battery last ?) and there is no point in that so next I thought I can put it on the unswitched +12V. That should work except, when I was playing with the M1 some time ago I accidently connected the ignition line to +12V leaving ground connected to ground and surprise the pc turned on. Now, I dont want that to happen in the car because the ignition wire may not be good enough to provide that much power.

The questions:
- is my memory good and can smth like that happen (ign+gnd = enough power to start pc)
- if I add the timing jumpers, will this happen as well (ign+gnd = start) ?
- is putting the switch on the gnd line good idea or is that a complete stupidity ?
or - how can I achieve my "wish" using any other method ?

ps. n00b here so speak really s-l-o-w

ps2. how do you guys connect the ignition line ? a technician told me to use the igntion fuse but its rather unprofesional to stick a thin wire around the fuse-leg and try to push the fuse in along with the wire sticking out.... ? I'm thinking of building some kind of extender that will fit into the fuse socket, and i'll solder the fuse onto it while there will be enough room to solder the wire to my pc (?)

THX!

**ARCTiC** · 09-08-2006, 10:27 PM

I assume there's something wrong here, or it's the M1 that is completely wrong. I'm using an M2 and my PSU *doesn't* turn on only with the IGN wire (and ground) tapped in.. it will require the main positive. Then check the sets, doesn't use the "dumb mode" (set the timings) and check if the problem still there.. if yes (apart blaming at your M1) discard these two option and go for the safest one: use a "2 lines" switch, and wire both positive and IGN (separately) on the switch... then you have the main power, plus the feature of the ignition power, until you switch everything on.
I guess anyway that the problem is your settings... switch it right.

For the IGN fuse, well you would take the IGN from you cigarette lighter (just be sure it works ONLY with IGN-ON!) then your fuse will be the cig-lighter one (it's ok, coz the IGN doesn't drawn power.. well assuming u solved that other problem before) and you're safe.

**simor** · 09-09-2006, 04:00 AM

I'm will put my voom apart, put the timing jumpers and play with the wires again to see what happens.

about the fuse, I know which fuse to use (the ignition one because cig is powered by unswitched +12 in my car) but my question was more about the technical side ie. how to actually connect my wire the the little fuse ...
GUess if my ign line turns out NOT to turn the pc on with the gnd only connected, then I'll wrap a very thin wire around one leg of the fuse and use that cause it falls off after soldering to the little (<1mm^2) contact on top of fuse.