The Revenge of Bambi

Although the dogs and I have been continuing our evening walks, there hasn't been much going on (either in the world or inside my head) warranting mention here.

Last night, though, we finally stumbled upon a bit of newsworthy activity. While climbing up the back of the hill, we came upon a full-grown deer crossing the street ahead of us. It quickly back-tracked into the front yard of the College Administrative office, and then off into the stand of trees bordering the old reservoir.

So.... a deer. Twenty years ago I'd start musing about how we must have turned a corner on the environment, and seen it as a sign of progress. But now my thoughts turned immediately to worries about deer ticks, Lyme disease, and unwanted nibbling of our garden. Funny how "vermin" can be such a flexible category.

Meanwhile, we'll check that the dog's vaccines are up to date, and start using the bug spray on pant legs.

Fwd: Compact Fluorescent bulbs - a lurking menace?

We've long assumed our second floor hall bathroom was haunted, specifically by a Poltergeist. How else to explain the shower mysteriously turning on in the middle of the night? Or the faucets that were carefully turned off, only to start dripping once your back
was turned?

OK, maybe it's the "we don't see many of those anymore" combination of steel valve housings and brass valve stems that were used, combined with rubber stop washers that have hardened over time to turn into perfect thermal-time-delay systems. Turn the valve off when hot
water's been running through, and when they cool off they open again. But, even after this advanced education in the perversity of mechanical objects, I was not prepared for the demonstration yesterday.

My daughter came out of the bathroom after taking her morning shower, and as she turned off the ceiling light.....it started flashing. Switch on, steady light; switch off, one blink every few
seconds. Huh?

Ok... diagnostics time: broken switch, or defective bulb? Switched in an incandescent bulb, all is well. Replace with another CFL, same results. I then took apart the fixture, but found nothing obviously wrong; no shorted wires, no damaged insulation. But, as I put it back together, I noticed that the ceiling was wet, the result of the muggy weather and steam from the shower. Hmmmm.......

A 100 Watt incandescent bulb draws a little under 1 amp at 120VAC. Thus, a 12 watt CFL draws something like 100ma. Still in a low-impedance happy place, as far as leakage currents and home wiring goes.

But, what's inside that bulb? I hypothesize there's a diode bridge going to a small capacitor to smooth out the current, followed by an offline switch-mode power converter, that chops the sorta-DC into 10-20 kHz, the better to allow a small inductor to serve as a current limiter and startup voltage booster. Turn on the AC, the DC voltage rises to the point that the switcher starts, which fires the lamp, and bada-bing, you're good to go. Turn off the AC, the DC voltage drops across the cap, the switcher shuts down, the light goes out.

But, what if there's some leakage current on the input, say from a ground-side light switch paralleled by the enclosure touching a damp surface? (Remember: back at the fuse box the neutral wire coming from that wall switch goes to the same ground bus that the grounding wire without a switch goes to. Input current via the leakage path is tiny, but on each cycle of the AC input some charge still transfers to the cap, the voltage of which rises until the switcher starts up, only to drain out all the juice and shut off again. Figure a duty cycle of maybe 1 msec on and seconds off, and you can imagine a few 10s of microAmps allowing the light to blink at partial brightness.

So, a warning to us all. If the next generation of ultra-efficient light sources remain incandescent compatible and are 10x as efficient as CFL, they may never turn off! After all, my home wiring is
insulated with COTTON DIPPED IN INDIA RUBBER, with wall switches that have 70 years' of flash-deposited metal spattered around the switch contacts. Once you start considering microAmp leakage currents, you'll see them everywhere. So, what to do? Refit all the wiring with teflon insulation, ceramic High-Z insulators, and leakage-current guard rings around all of the neutral line connections? The expense! But, otherwise we might die from lack of sleep, as our lights conspire against us to shine into our eyes all night long!

(There's a wee bit of exaggeration here, in case anyone is taking my latter ranting seriously. :-)

Where do they find the time?

An interesting article I stumbled upon puts forth these interesting statistics:

    Number of human hours invested in creating/editing/updating Wikipedia:  100 Million (worldwide, total)

    Number of human hours spent watching TV: 200 Billion (in the US alone, this year)

    Number of human hours spent in the US watching TV ads, over the last weekend: 100 Million

There's also more goodness about the industrial revolution being fueled by Gin, and four-year-olds who think that TV sets come with a mouse attached. ....

The corrected guide to University studies

During our walk to work in the rain yesterday, Rebecca pointed out the number of earthworms on the wet sidewalk.  I admitted to not liking them, and she mentioned the 'ick' factor of having to dissect one. 

"I was glad I didn't have to dissect a cat in Bio. Did Sarah have to do a cat?"   I said probably not, quoting the joke truism "her Bio is now mostly Chemistry."  Which led to this list:

Business is now mostly Economics
Economics is now mostly Sociology
Sociology is now mostly Psychology
Psychology is now mostly Biology
Biology is now mostly Chemistry
Chemistry is now mostly Physics
Physics is now mostly Math
Math is now mostly Number Theory
Number Theory is now mostly Computational Science
Computational Science used to be called Programming
And nobody teaches Programming;

After all, this is a University, not a Trade School!

When we last left our hero....

Ok, so I'm not Flash Gordon battling the evil Dr Zarkov, but there is a rather significant gap in the storytelling which needs to be bridged somehow. So, let's throw in a couple of flashback scenes, cue the narrator, and get on with it.

The old job did indeed go 'poof', which in the grand scheme of things was probably a very good thing. The group I was in was in a death spiral, I was stressed out, and frustrated that there didn't seem to be any way to reverse the negative trends, but was too much of a team player to just up and walk away. Dumb, dumb, dumb.

So, once I got over the puritanical embarrassment of being without a job, I was able to relax, get my health back on track, and then start some selective job searching. I'm now settled in a new gig with a company with great possibilities ahead of it, doing something rather different than before. No travel, no presentations to sales prospects, and no two hour conference calls to discuss the status of the proposal for the modification to the report on the plan, all of which is subject to change depending on who the CEO plays golf with tomorrow morning.

So, life is pretty good.

Which is not to say that the dogs don't need to be walked, and that I won't continue my musings about life, the universe, and everything as I trot up and down the hills with them. Hopefully now that the basics are covered, there will be a few less storm clouds to muse upon, and a few more butterflies. And, after all, there are still foxes in the neighbor's back yard to surprise us.