[mdlug] OT: single resistor source?

[list1c30fe42 at bellsouth.net]

Joseph,

> 	(Secondarily, series resistors need to be at the wattage rating, 
> wattage isn't generally additive along with the resistance, they really 
> should be 1/2W or better!)

Can you please explain why series resisters
need to be at the wattage rating?
Can you please explain why (assuming adequate air circulation)
wattage rating isn't generally additive along with resistance?

Power dissipated by a resistive load is I^2 R
(i.e. current squared times resistance).
Series resisters share the same current, I,
so the power to be dissipated by each resister
in series is proportional to its resistance, R.
So long as inductance, capacitance, and heat loss is not an issue,
I understand that
n equivalent resisters of resistance, R, and power dissipation, P,
form in series, a composite resister of resistance, n*R,
and power dissipation, n*P.

TIA,
--
Bob