At 03:59 PM 11/20/2006, William "Chops" Westfield wrote: > I vaguely recall an "electronics project" where one made an >"impossible machine" that capitalized on some of these "oh, it looks >like an X, it must be an X" sort of misconception. I'm probably wrong here, but I have vague recollection of something like this in an old text book "The Boy Electrician" (late '50s? early '60s?). This was a supposedly series circuit, with 2- SPST switches in series with 2- 110V lamps, the whole thing running from 115Vac. The idea was: both switches had to be closed before the lamps would light. However, hidden inside each of the switches and lamp bases was a diode connected across the device. Turning one switch on caused one lamp to light; turning the other switch on caused the other lamp to light. The picture showed them using really old style porcelain surface-mounted switches and lampholders (the kind used when installing electric lighting in a house that formerly had no such thing) mounted to a board, with a single-conductor wire connecting all the devices in series. The diodes were hidden under the top cover of the devices. I distinctly remember being highly amused at how easy it was to fool some people - and how ** I ** would have been stumped if someone would have shown me this thing and asked me how it worked. dwayne -- Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA (780) 489-3199 voice (780) 487-6397 fax Celebrating 22 years of Engineering Innovation (1984 - 2006) .-. .-. .-. .-. .-. .-. .-. .-. .-. .- `-' `-' `-' `-' `-' `-' `-' `-' `-' Do NOT send unsolicited commercial email to this email address. This message neither grants consent to receive unsolicited commercial email nor is intended to solicit commercial email. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist