Errors
More About PWM
Update 3/16/13: Ok, my graphs (and some conclusions drawn from them) had a serious flaw. I’d modeled both the growth and decay curves incorrectly, and this caused current to drop to zero in a lot of situations where it wouldn’t have. Don provided an interesting simulator model, which led me to do some more reading and correct my model. It’s still not complete, but rather than re-do this post, I’m adding a new one that is the correction. I’ll leave this one here for history’s sake, but please see the new one.
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Measure Twice, Cut Once, Get it Wrong Anyway
11 May 2010 00:24 Filed in: Construction,Errors
Some days it doesn’t pay to go into the railroad room. I had spent the weekend carving foam for the hillside that separates the Urban Station scene and the Riverside Station scene from the large river. Just before I was ready to glue it down, I decided to check the clearance of my subway tunnel, and found it seriously wrong. After realizing that my “two-inch” insulation foam was 1.75 inches thick (and I’m sure I measured it before), and raising it up with a chunk of gatorboard (barely visible above, on the left below the pink foam), I still had a bit of a problem. Read More...
