Thread: Two power supplies

I've tested the power draw on my pc (M1-ATX, M10000) and when its running on its own its pulling about 3.2A onto the M1.

When I put it into standby, its pulling about 0.18A onto the M1, and when I pull all the external USB devices, this drops down to 0.1A in standby.

Now, 0.1A isn't a heck of a lot and with a 90AH battery in a car that gets used every day (longest period unused is 40 hours at the weekend - it "should" last 900 hours at 0.1A), I reckon I can put it into stanby and not have any real battery issues. This wouldgive me very rapid start times, without the hibernation issues (current best return from hibernation is a paltry 40s). For holiday periods I can always hibernate it/turn it off.

Installing this in my car is not an issue per se, but running power to all of the peripherals - touchscreen, USB hub, external audio card, USB TV, bluetooth , external HD (NEO jukebox with all my MP3s on) from the existing M1 will overpower it.

I want to have stabilised voltages to all the bits, so I'm considering getting EITHER

an M2-ATX to replace the existing M1 and then tapping all the power supplies into the PC, but this would increase the standby current draw to 2 or 3x what it could be.

OR

Using an "external" M2 to drive all the peripherals is a neat solution as far as I can see, as I can set a "power off" delay and it'll give me enough amps at +12v to drive the screen,the NEO jukebox HD and possibly the radio tuner as well

The neatest thing I thought of though is being able to cut the power supply to the external USB devices, which, although some of them have their own external +5V supply, they do draw power down the USB cables when the PC is in standby. So, by tapping into the USB +5V lead from the PC to the USB hub and using a relay to disconnect that when the IGN is off, I should be able to get back to the 0.1A current that the M10000 needs in standby.

Are there any reasons why this wouldn't work?

Cheers

Mondy