ok, high guys

http://www.maplin.co.uk/Module.aspx?ModuleNo=37526

if i use this relay, can i achieve the following correctly

i want to put a switch on my dash to "auto boot" when my car door is opened (light comes on)

now what i see is this




now this would turn on the pc if its not turned on, and not turn it off if the src comes on again, etc... correct?

sry for the **** poor diagram, but basically

the usb power is 5v, if i then put a wire for the power switch to go through the lower relay 87a [off position] it will only work if the usb is on, therefore pc is off, correct? - sorry, just learning this and dont wanna reck the usb ports and wanna check this is a good setup, and any advice etc would be greatly appriciated, - ie would i need resistors etc

oh also, i will have a power switch in the src for the light, so as to be able to not turn the pc on automatically...

if this works as i expect i will then be able to power my amps etc correctly and may even rid myself of my car headunit that i just upgraded also lol :P