scott wrote:
>> You you mean stuff like if you put power through a wire, it heats up, 
>> and resistance varies by temperature?
> 
> Yes pretty much, now imagine that in your design the resistance of the 
> wire changes enough to have a big impact on how your circuit works.  If 
> you connect an LED to a voltage source and gradually turn up the voltage 
> from 0 volts, you will see that almost no current flows, it's like 
> nothing was connected inside.  But suddenly, you will get to around 2V 
> or something the current will shoot upwards, and from then on you only 
> need make tiny increments to the voltage and the current will keep 
> getting larger and larger very quickly until the LED blows haha

Is that why LEDs display a non-linear brightness response too?

>> The whole "electricity chooses the easiest path" makes it sound like 
>> when an easier path becomes available, all the current goes down that 
>> and ignores the other paths! o_O
> 
> If the "easiest" path is of *much* lower resistance than the others, 
> then yeh you can usually ignore the others.

I presume you mean you can "ignore" them for the purposes of figuring 
out the total current flowing through the system. Clearly the current 
flowing through each path only depends on the resistence of that path 
and the potential difference...

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