What is the different when a resistor is on the High or Low side in the circuit?

[Chriss]

Hi!
I'm curious about what is the difference when a resistor is put in series in a lets say 12vdc circuit where a motor is powered up
in the high side or low side?
I mean if the resistor is between the battery +  and motor or when the resistor is put between the motor - and battery - ?

I also saw sometime in circuit's where the current limiting resistor for the LED are put to LED and gnd but also the opposite.

Thanks you for any explanation.

[Nusa]

When the circuit is as simple as you describe, it doesn't make any difference functionally. Current is limited for the entire circuit, not just the side it's on.

[Chriss]

Thanks for the fast replay.
Actually yes, I mean the resistor is for current limiting, and nothing else.
So that means there is no "right" or "wrong" way if the resistor is for current limiting only, like I described?

Thanks.

[greenpossum]

Electrically there is no difference but sometimes there is an advantage elsewhere due to the location. For example when I had an array of LEDs where the drivers were sinking current, putting the limiting resistors on the high side allowed me to use a resistor network to save space as the common pin of the network went to the postive supply..

[digsys]

It is "traditionally" put in the high side - especially if there are several devices powered from that supply eg vehicles etc In many cases, you want to keep the 0V REF CLEAN.
The main "old" reason that resistors were put in the "low" side was for current sensing, but these days there are heaps of high side current sense ICs that can go up to quite high voltages, so even that is not necessary any more.