Some time back I had a class on the National Electric Codes. Instructor said there was a big feud between Edison and Westinghouse. As I remember his speech, NY state was getting ready to electrocute someone for a capital crime, and one was for AC and the other for DC. When the state decided to use DC for the deed and then after it was done, the other one jumped up and pointed out how dangerous DC current was. From that instructors tale, that's how we came to use AC.
No idea of it's a true story or not, but it did make an interesting class.
I'd guess that's not the real story, since you can use a smaller size wire to carry a higher voltage/current and just use (in a basic sense) one wire for AC and just plug the other lead into the dirt.
Most of the stuff I do uses either 28VDC or 115V/400cycle AC. The 28VDC is nothing, but the 115/400 hurts big time. Can't let it go.
And in the marine world, the Coast Guard mandates what color wire will be used for a specific circuit.
:rofl:
Tim, it's amazing, but you got the same info I have gotten through the years....and same stories.....my mamory is fried....
I remember playing with a HUGE black panel box full of stage lighting transformers and a trick known as UNGAR bulbs....had that large old base for the filament and one pole of the rectifier tube....the plate had the cap on top of the bulbs they glowed orange of course, like any other rectum flyer tube....and they would change color with the amount of current passed through them....blue/green.....like most other higher powered vacuum tubes....
I was like 6th grade, something, maybe 8th at latest....
so it put out 28 volts DC current, the crapassitors were not good in this unit....age or tech, not sure why....but the output was ragged....that much I know from a old Heathkit scope I had one of them Frankenstein things that shows the sine wave on it in the movies....and the non geek audience looked at it like it was outtta here space or something.....
so anyway, the true gig involving that supply was the output was pretty close to 28 VDC.....and the input was 110 VAC....fine for ME, plug it into the light socket....Dads house was wired in steel jacketed cable known as BX back when knights were bold....so I upped the screw in fuse in the panel to WAY over rating.....KEE=RIST why I was not killed I dunno...
so anyway there was this WW2/Korean electronic surplus store on the way home from school, I stopped in every day almost to say hello and buy whatever I could afford, not much I can assure you, but enough to fuck around with....
and in that store was this DYNOMOTOR...that is a motor and generator interwoven on the same shaft....the larger current/lower voltage brushes on one end, and the much higher voltage/lower current on the other end....
keep in mind this shit looked like the input to a starter motor, and the output of say a blower motor....size of commutator and such.....
so I fired up this trick, it was about 4-5" diameter maybe 15" long, had a aluminum mounting plate on it and a round connector on bottom, silver contacts so the thing would wind up pretty good, with no load on it....I mean really torque up like a digger with no wheels/dyno.....
then I would take the 600 volt+ rated output wire and short it out, the magnetics and inertia would do their physics trick, and the wires I had would get hot and fry....
so up the gauge, and insulation....and LENGTH....
keep in mind this shit had a common ground from input to output....just this huge voltage potential differential, and under NO load the thing would wind up like MAD.....
SO I scared the shit out of a bunch of similar minded geek buddies with a demo on what it could do....
as in handle the output cable like a whip, and flash the open end over the common ground.....and the resulting ARC was rather impressive....the poor dynomotor would go into a total stall and destruct mode for a instant....let it wind up and flash it again.....
sparks of burnt/melted copper all over the joint....
mom was scared as to WTF I was doing, Dad was concerned, but not knowing much over 'lectrickery' he let it go.....
I remember a electrician came to the house, and when I told him I was blowing SIXTY AMP screw in fuses outta that old box, he about shit.....warned my father it was going to BE a house fire if I didn't cut that shit OUT, as in NOW....
All true, and all stupid, I swear.....
:rofl::rofl::twitch:
