As described in the history, version 1 had issues when it came to power, with a very complex starting procedure. For version 2, this had to change!
In the early stages of version 2, I entertained the idea of using a Sproggy 2.8plus board. I bought the components and got the circuit shipped to me, but unfortunatly the load was too much, and the Sproggy couldn't handle it. At the time, the Opus offerings where priced a little out of my budget, so I fell back on the inverter.
The inverter has a couple of advantages over the 12v DC power supply, the biggest being that when the player box was in the office, I could run it from 110v. Another advantage was that the PC was closer to stock, if anything broke it was an easy, cheap fix.
The inverter I chose came from Walmart, it is rated at 350Watts continuous and 700Watts peak. The power supply for the PC is a standard 300Watt ATX supply. The inverter is connected via a fused wire to the battery. The fuse is at the battery end, and rated for 30Amps. At the inverter end, there is a relay that was originally designed for the fuel pump, the main feed is connected to the common, the normally open contact is connected to the inverter, the coil is connected to the (now unused) radio fuse at the fuse panel. Ground is a short cable connected to the bodywork. All high current paths are wired with 10AWG cable, the switching line is 18AWG.
When the key is in accessory or run, the relay is closed, and the inverter gets 12v directly from the battery, when the key is in off or start, the coil is de-energized and the inverter is disconnected from the power. This cures the v1 problem of having to run around and reset the inverter after the engine is started. However as the power is off during start, the player doesn't actually start playing until about 25-30 seconds after the engine is started. To get around this will require a tank circuit that at the moment I am disinclined to build.