April 28, 2005 11:30
Quentin Wrote:ginginsman Wrote:Unless I'm mistaken, a DV-DV converter (12 {boat} --> 18 {Mini}) still has to use a DC->AC->DC setup to get its otput: it may be a bit more efficient as all you have to do is chop the DC to get it into the transformer, not convert it to MSW or pure sine-wave 60 hz AC. For the testing stages I am at I'll be happy with an inverter for the moment. A DC regulator assumes you're using a voltage lower than the 12 VDC input, which we're not here.
One worry I have is that we are all basing our plans on what the Mac Mini power supply is delivering.... perhaps we should hold our horses and find out what the Mac Mini itself is expecting/needs in the way of input power spec. I e-mailed Apple a few days ago and have had no answer yet.
Q
Sorry, but that is strighforward: it expects 18.5 VDC @ 4.5 amps. My worries aren't about getting that part right, they're about making sure the mini doesn't get spikes or voltage drops when the engine is started, for example. Portables are insulated from that by their batteries; a mini is not, so whatever inverter or converter is used needs to provide some protection, unless the internal circuitry of the mini (downstream of its own power supply) provides that, and I don't have any inside contacts at Apple to tell me that. Anyone know an Apple certified techie?