Note on history of E-I-R tables format

Thread Starter

rogerk

Joined Jul 2, 2011
1
Took electrical-code class in 1999 in Florida taught by local inspector [chief] Jack Leahy. I recall his wife earlier originated the P[power]-E-I-R table used in his classes. P-E-I-R very handy. Thanks to all who contributed to AllAboutCircuits...also very helpful.
 

Adjuster

Joined Dec 26, 2010
2,148
Note on history of E-I-R tables format? That's intriguing, but many readers will only be able to guess what an E-I-R table was.

Perhaps it was a handy lookup table for doing Ohm's law calculations, the sort of "ready reckoner" that was more common back in the days before we had so many computers and portable calculators?

Or was it a more general reminder of useful information, maybe including some details of wiring codes and electrical regulations, or such things as wire tables, screw threads and drill sizes, formulae and constants?

It would be interesting to know...
 

Wendy

Joined Mar 24, 2008
23,415
Another name for E-I-R, Ohm's Law. I always liked the pyramid myself.

Welcome to AAC.

Not sure if this was the right forum for this, but the mods will figure it out. It is borderline.
 

#12

Joined Nov 30, 2010
18,224
Interesting. I learned about the WIRE wheel in 1968. W for watts, I for current, R for resistance, and E for electromotive force (voltage). This makes me think the idea was originated before 1999.
 

Wendy

Joined Mar 24, 2008
23,415
I suspect so, most serious electronic concepts of that nature were pretty developed in the 30's. Time for Google.
 
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