conservation is treason
Thursday, November 17 2005
This afternoon I was driving Judas the Prius home from a housecall in Lafayetteville (on the east bank of the Hudson near the Taconic Parkway). Stopped at the intersection between 199 and 9W I saw another Prius pass me on the right, the first other Prius I'd seen since getting the new car. Then I saw this rough looking dude in a pickup truck slathered with magnetic ribbons. He gave me an evil look, similar to the one Gretchen reserves for Hummers and people with camouflage "Freedom Isn't Free" ribbons. Illogical as it might be, there are actually people who think the conservation of fossil fuel is unAmerican. I hadn't even had any direct evidence of this when I designed the following bumpersticker, which I have yet to produce.
Today I decided that the absolutely best method for robotically controlling the circulation of water in my solar heating system would be to have two sensors read via op amps, with these controlling the state of a digital flip flop. When the heat is sufficient in the panel, the flip flop is flipped on, energizing a relay and causing water to flow. Then when heat falls below a sufficiency threshold in the basement that flip flop is flopped off. Properly tuned, a system like this could be made to turn on and off multiple times per day, deploying the pump only when there is extremely hot water to transport.
The first flip flop I wanted to try was a CMOS 4013 that has lain dormant in my IC collection since 1982. Unfortunately, though, to use such a circuit would require a number of digital NOT gates (miniaturized naysayers capable of reliably turning any logical truth into a logical falsehood or vice versa), and I wanted to keep things simple. Ideally I'd use a 74LS74, but (at least in this application) I dislike the restrictive nature of 74YYXX power supply requirements.
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