Usefull resistor coulours

[Happyguy]

Hi,

This web page just helped me enormously. Sharing the wealth.

www.hobby-hour.com/electronics/resistor_color_code.php

[newey]

Thanks, HG-

I added this to our links page, under "Calculators and other Tools"

[ChrisK]

Interesting summary of resistors. They have most of it right,

The statement

The E24 range however is not a subset of the E96(1%) and E192(0.5% or less) range.

is incorrect.

The E24 range is a subset of the E48 range, which is a subset of the E96 range. The numbers don't match since the E24 ones are rounded to two digits.

The "E", or exponent, numbers are the number of steps per decade of values. For a 1% resistor, there are 96 values derived from the 96th root of 10, for constant ratio spans thru each decade.

E Span Ratio Multiplier
6 1.467799 or */ 1.211527, the "20"% resistor
12 1.211527 or */ 1.100694, the 10% resistor
24 1.100694 or */ 1.049139, the "5"% resistor
48 1.049139 or */ 1.024275, the 2% resistor
96 1.024275 or */ 1.012064, the 1% resistor
192 1.012064 or */ 1.006014, the "0.5"% resistor


In fact, the tolerances themselves are rounded to convenient values.

[JohnH]

That is a useful link indeed. To be quite honest, I never found out how to read the 5-band system for low tolerance resistors, until reading this.

John

[ChrisK]

AND....the reliability rate proves beyond any shadow of doubt that only fools run resistors at or near their rated wattage.

Over a 30 career as an OEM electronics design engineer, I've never designed anything that uses one at over 50% of the rated wattage.