What is the best way to detect motor stall.

[PlatinumT]

What is the best way to detect motor stall with out a series resistor.

 

[IanP]

One option is a shaft rotary encoder, cheaper option is a magnet and hall-efect sensor. Both will sense rotation (or even rpm if necessary)..

Another option is sensing current using, again, hall-efect sensor..

 

[nicleo]

Motor stalls does not mean the current must be zero, right? Pls correct me if I'm wrong.

 

[platonas]

No, current is not zero, Ianp means that the current increases and by monitoring this you can find out what is wrong.
The best method is to monitor the rotation of the shaft by any method you prefer. (described on previous posts)