I have an OPUS 90W setup to power my LCD as well as my carpc, plenty of current room to spare. However, this means that while the carpc is shutting down, the LCD is still on. Not that big of an issue, but I'd rather have it off.
I put the power of the LCD from the OPUS in series with a normally-open SPDT relay with the coils connected to my car's ACC line. So when I turn off the car, the LCD turns off. Works great, but if I turn on the car again before the carpc is shutting down, the LCD will turn on and the PSU will enable it's over-current protection and shut down!
As you can see, the relay will turn on the LCD once ACC is on. Turning it on while the PSU is already on will kill the PSU.
|------| __ 12V _____/ ____ |-----|
| OPUS | relay | LCD |
|------| __ GND ___________ |-----|
Any ideas as how I can battle this?