document updated 22 years ago, on Feb 20, 2004

Basic features:

Power as many perhipherals as possible
Minimize space usage
Turn power on and off to those devices in an intelligent way (eg. 12 volts is basically always available in the car, until the battery dies...)

Requirements:

USB 2.0 7-port hub — 5v, 2amp
Garmin Geko 201 — 3v, ?amp
Motorola A920 — 4.4v, 1.5amp (5 volts minus one diode drop)
Dell Latitude C640 — 20volts, 5 amps or something (almost certainly will have to be handled by a separate dedicated PSU)
Sound Blaster USB Audigy2: 5 volts
USB SB Extigy: 12v input
USB Sound Blaster MP3+: has no external power connections, just powered from USB, but likely requires an externally-powered hub

As I see it, these are the possible options:

Wire up the inverter, plug in all wall-warts [big, no power control]
DC-DC ATX power supply (eg. at bottom of this page). May need an external 12v regulator as below. Definitely needs external shutdown control. [also pretty big]. (The Opus 90-watt apparently includes a shutdown controller, is pretty small, but costs $162, is still bigger than bricks, and only puts out 6A 5V).
Mini-ITX power supply w/ external 12v regulator and shutdown control (ITPS), all from here
Buy separate DC-DC 12v - 5v and 3.3v non-isolated converters at around 10amps each, ones that can handle up to maybe 18v surges. Power would only be turned on when a powered-up laptop was detected on the other end of the USB cable. (simple and direct method, also allows running off of the car battery when the human wants to) [cheaper if will go to 18v (eg. like this one), more powerful and reliable than above]
Build SMPSs from scratch, otherwise do similarly to above. [hard as hell]

Matches:

BWR-5/6-3.3/7-D12 (10-18v in, 5v 6A out, 3.3v 7A out), $75 shipped
The people over at mp3car.com seem to be in love with the Opus 150watt for around $200. (includes a shutdown controller, apparently)

General links: