I've thought of doing this for a while & knew it should be simple.... in theory.
I have just finished hooking it up & it works great.... my laptop is now startup with ign, shut down with key off, being controlled by my opus 150 that I have left over from my previous p4 install.
I now have my screen powered off of the opus & all usb periferals & external dvd & 3.5" hard drives.... gps antenna, etc... & I have plenty of power for expansion.
the laptop itself is actually powered by a seperate 20v 3.5a supply.... unless your laptop happens to run at 12v you will need a seperate power supply for the laptop.... but this means that the opus has that much more headroom for expansion....
truth is, it's probably not the cheapest way to do this, & I don't know if it would be worth it to actually go out & buy an opus 150 for your laptop install, but as a startup/shutdown controller & 12v/5v power supply it does fine(the 3.3v is harder to make use off... maybe led's?)
..if you happen to already have a dc-dc atx power supply you can use it with your laptop like this
the trick to using an atx supply like this is to have communication between the laptop board & the power supply.... they call this a handshake between the board & supply.... sounds complicated but it's really simple...
the atx power supply (opus & all others) only give 5v on one wire constant when off...this is a purple wire in the atx mb harness... this is called standby power.....this is not used in this installation
when the ign is turned on the opus waits it's required 10 seconds.... then sends a "pulse" to the motherboard on switch... making a momentary contact..... pressing the power button...... this obviously should be connected to the laptop switch...
at this point the power supply has not powered anything..... no 12v or 5v... only the 5 v standby purple wire has power at this point, which in this install powers nothing..... if the opus doesn't "see" the motherboard power up it will send another "pulse" after 5 sec.'s or so..... & repeat this behavior until the computer tells the opus it turned on or the ign is switched back off
now the trick here is to have the laptop "tell" the opus that it has turned on... when the power supply knows the laptop has turned on it will imediately power up all it's rails.... everything comes up & remains up for the whole cycle..
the way to have the laptop do this is to tap into a usb cable plugged into the laptop... just open up a cable between the laptop & the usb hub... inside all the insulation & ground shield you should find 4 wires.... red, black, green & white....
the black & the red are 5v - & +... these should be tapped & extended out of the harness... then carefully re-wrap & replace sheilding at the splice.... a thin strip of tin foil wrapped to connect the interupted shield does the job here...
this red & black from the usb of the laptop should now be used to trip a 5v relay... this will power up as soon as the laptop responds to the "on pulse" from the opus & turns on..... this relay should be used to connect a ground from the opus togeather with a green wire that is at the main atx mb connection from the opus.... this green wire going to ground is what tells the power supply that the system has powered up... causing the power supply to fully power up.... walla..... done...... simple & effective....
shutdown is the opposite... the opus sends out it's "pulse" then the laptop shuts down.... when the laptop powers down it cuts power at the 5v usb & this in turn ungrounds the green wire of the opus by opening the 5v relay.... the opus then turns off
if my discription is unclear I'll try to clarify this with a diagram.... but I think you can understand what I've tried to explain..... hope this helps someone
the 5v relay can be seen mounted to the opus at the top right
Linear Mode
