Direct DC vice AC conversion

[charles]

[warmrain]

We did just that... made our own cables, purchased a kit of voltage adapter things and it works fine.

The nice thing about the little power bricks though is that they regulate the voltage for things that aren't intended to run form 10.5 to 14.5 volts.

~Cars

[mimoza]

True about the voltage variability. If one is handy with wires, a Zener diode and a couple of resistors will make a fine step-down converter with the Zener acting as a regulator. There is a small cost in power as compared to a converter without the Zener, but it is much smaller than the waste in inverting/rectifying.
But also consider this: If you are stepping down to, say, 5 volts using only resistors, than that 10.5 to 14.5 variance becomes a 4.2 to 5.8 variance, which is somewhat less scary.
If you follow a few simple rules for your sensitive electronics you can reduce the variance even further, e.g., never crank the engine from the battery bank powering your computer.

Cars mentioned that those wall-warts regulate the voltage; in addition they limit the amount of current delivered - so you won't blow up your cell phone battery by charging it too fast.

Think twice before converting to an all DC setup, especially if you don't have a reasonable understanding of the electronics involved. If the small electronics in question have a car adapter available, use that. Is there one available for the LCD TV? I would be very cautious about using an unregulated adapter for your mass storage device.

BTW, what company is this that will make the cables? I would like to check them out. If this company produces a voltage regulated and current limited cable, and will stand behind their stuff, then I say go for it. Just be sure they know all the specs on your wall wart power supplies.

[Great_Aardvark]

As I move through boats over the years I decided to try and be able to have as many of of my dockside conveniences available to me when anchored as possible. The first effort was to use converters as have been described but on this boat I have a different approach which is everything should be 12 volt. My TV and home theater are 12 volt (home theater is an IPod with a car adapter and contains both music and roughly 80 DVDs), cabin heater (Webasco diesel heater), blender and so on. My computer uses a adapter that I used on the airplanes which is the only one I now have to use. By getting devices setup that only use 12 volt there is no energy loss in the adapters. Right now I am setting up the boat for as low power consumption as possible (includes converting all lights both cabin and navigation to LEDs) so I try to avoid adapters when ever possible. As good resource for 12 volt devices are trucker sites.

Tony