On 19 Nov 2014 00:20:20 +0000 (GMT), Theo Markettos
wrote:

Terry Casey wrote:
Anybody who thinks that the ranges of resistor values follow some weird
random sequence might like to look at this drawing I produced which shows
how neatly the values in the various ranges neatly dovetail together:

https://dl.dropboxusercontent.com/u/24301298/Res_Tolerance.png

That's a very nice plot!

The other thing I find myself doing is thinking 'it's a 430 ohm resistor so
I have to replace it with one' rather than wondering 'so what is it actually
doing?'. If it sets the current for an LED, say, it doesn't really matter
if it's 390 or 470. If it's in some precision measuring circuit then maybe
it does.

On the other hand, if a resistor is marked 10.0 K (eg 4 value bands or 4
printed numbers - 1002) then that means it is a high precision resistor and
you might want to pay more attention.

Theo

Seeing two resistors in parallel or in series is a good clue that the
designer was aiming for an exact value.


--

Graham.

%Profound_observation%