This article was posted to the Usenet group alt.hackers in
1995; any technical information is probably outdated.
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Re: Electronic Highway Signs
Article: 7665 of alt.hackers Newsgroups: alt.hackers From: grobson@netcom.com (Gary D. Robson) Subject: Re: Electronic Highway Signs Message-ID: grobsonD73G6B.3Cx@netcom.com Organization: In alt.hackers? Are you kidding? X-Newsreader: TIN [version 1.2 PL1] Date: Sat, 15 Apr 1995 20:42:11 GMT Approved: ApprovalMeister Lines: 42 Sender: grobson@netcom16.netcom.com Status: RO
marlowe (marlowe@io.com) wrote: : We wanted to close captioned the class for the thinking impaired, but the : prof who would have thought it was cool died... You got me thinking back to the lack of profs who thought such things were cool when I was in college (how's *that* for a convoluted sentence?), and it made me recall this ObHack: A friend and I scrounged up an aquarium pump, a conical taillight from an old (60's) American car, a large capacitor, a toggle switch, a momentary switch, a small light bulb, a 9v battery, and some 4" x 1/2" metal plates. We attached the plates around the housing of the aquarium pump (which was about 4" high and 3" in diameter), so that they weren't touching each other. The cap was placed inside the housing (we removed the pump itself), and set to charge using a regulator hooked to the 110 power cord. We hooked the + side to every other metal plate, and the - side to the remaining ones through a momentary switch on the bottom of the housing, so that it was quite difficult to lift the pump housing without touching at least one + and one - plate. The momentary switch was set so that it was open when the pump housing was set on a flat surface, closed when lifted. We then hooked up a 9v battery, the timing circuit (forgot to mention that in the parts list above), the switch, and a lightbulb, completely independant of the other circuit, and placed it under the red taillight cover, which we mounted on top of the housing. All that remained was to set it on a table with a sign saying "do not lift," and turn on the switch. There it sat, with the little light blinking. We sat back and watched. The best response was the fellow who touched it gently (no problem). He then carefully unplugged it. The light kept blinking. He flipped the toggle switch and the light stopped. Mightily pleased with himself, he then picked it up and got zapped. We were awfully easily amused back then... -- /---------------------------- Gary Robson ----------------------------\ | Internet: grobson@netcom.com | "If it ain't broke, fix it anyway. | | CompuServe: 76130,1111 | How else can you truly learn it?" | \---------------------------------------------------------------------/
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