~!@#$%^&*() Windoze! I was editing a message here and needed to put the machine in sleep mode--whereupon it crashed (BSOD) losing my work-in-progress and forcing a cold boot while I'm running on battery ... and I'll have to do a full file system check later.
Anyhow ... where NJC haz bin:
I had my attention drawn to a suspended project, the W.Marshall Leach-based headamp. In order to keep it running longer and more consistently on the batteries, I put a voltage stabilization network in. It wasn't good enough, so I added negative feedback, which unfortunately seems also to have fed back signal ... which I didn't expect. That reduced the gain from 20x to 2x. 20x is just barely enough.
So ... when I put it down before I was looking at ladder filters in the voltage level feedbacks. But since I never fully internalized filter theory, I have to go back to Budak. This is really a classic, but the growing importance of digital and FIR filters has probably pushed the book out of the mainstream. (Note the number of offers under $150.)
I've spent the last couple of days looking at better voltage stabilization. Unfortunately, the very simple network does not yield to easy analysis. I'm sure someone, somewhere has a good set of formulas, but I have no idea where to look. I've been doing algebra trying to get usable-enough formula. I'm sure there's one to be had, but it's not coming out, and I've spent too much time.
Worse, I've got a set of experiments worth running, but they really want a test rig ... and if I have to build one I'd like to make it re-usable, and ... well. there's 20 hours of careful measuring and drilling and wiring and soldering, and of course the parts to buy.
Sigh. And week after next, I'm going to visit my brother.
Do you see why Paddy isn't at work today?
I have gotten some stuff done, just not in the last 48 hours. I'm going to get to work now, while trying to keep a sober head on the circuit work. Drill guide ... angle iron to clamp the drill guide to ... how to measure from the non-parallel sides of the drill guide ... how many crosspoint pushbuttons ... how many binding posts ... aarghh!!!!