I worked out a power supply for my DTV system. I'm still working on getting it online as a portable. Right now I've got a good screen for it, and the whole schebang housed in a butt-ugly RadioShack enclosure with all the ports exposed out the side. PS/2, IEC (DIN-6) and Joystick (DB-9) are all mounted.
The DTV portable is going to need a 7.0v to 9.0v line for the screen, a 5v line for the PS/2 keyboard, and a 3.3v line for the DTV itself. Using some scavenged parts, some free samples from National, and a little elbow grease, I worked up a schematic:
The battery I'm using is seven 1.2v NiCd cells I scavenged from next door when Spatialight moved its R&D operation to Korea and let the whole building come in and pick over their trash. I made out like a bandit, scoring a ton of great parts and connectors and stuff.
Anyways, after burning my fingers for a few hours, I finally ended up with:
The outputs are on the right. The top is black, that's ground. Below it is green, that's 3.3v. Below that is red, that's 5.0v, and the purple line is unregulated 8.0v-ish straight off the battery. The LCD screen I'm using has its own voltage regulators, so I'm going to feed the battery directly to the screen for now. ·