Tuesday, September 08, 2015

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8 comments:

OregonGuy said...

Either that, or it's a power supply.
.

Anonymous said...

Oregon Guy, should it not then be "OHMMMMMMMM"??

Anonymous said...

I suppose you just couldn't resist...

lumberjack said...

I tried to resist, but it was futile.

Larry Sheldon said...

Should be "megohmmmmmmmmmm".

markm said...

Larry, the color coded value is brown, black, gold, where gold is a multiplier of 10^-1, so it's 1.0 ohm.

But the 4th band (tolerance) is yellow. I find that this is the code for 5% tolerance in high-voltage resistors, instead of gold - because you don't want high-voltage resistors painted with the metallic flakes that make gold paint glitter. You'll have trouble ordering a 1 ohm high voltage resistor. Put high voltage (IIRC, 400V and up) across a 1 ohm resistor and you get high current and high-squared power - say, 160KW. To meet that spec, you don't order a resistor, you order an electric heater - custom-made, because it's too much heat (and too high an electric bill) for anything but an industrial use. If you could order that resistor, it would have to be huge ... heh. Did the cartoonist actually understand that, or is it a coincidence?

But here is the other problem: this huge 1 ohm 160KW high voltage resistor is unsafely painted with metallic flakes anyway, in the third band.

Larry Sheldon said...

I made assumptions about artistic license and came up with brown black green gold--a fairly commons size back in the day.

Larry Sheldon said...

At one point in my life I worked on equipment that had a decade switch in it and the resistors (not color-coded) had values like 1600 k megohms, which in another point in my life would be numbers reported by a megger as "insulation resistance.

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