Thread: which power controller can do this?

This is what i need- when I give it an input, say 9 to 14 volts, it will give an output to a relay to turn my inverter on, when I remove the input, I need it to give a pulse to the compuuter power switch to tell it to hibernate and then wait about 20 seconds to turn off the inverter. cheap and home made is best, I have plenty of relays and stuff laying around.