Load Current Sensing

[threewheeler7]

If i where driving a small dc brushed motor from an hbrige, what would be a good circuit to sense when the motor drew a certain current (maybe set by a small pot) and would output a logical 1 when it reached that draw? i hope i made that clear enough.

 

[Sceadwian]

The simplest way to do active current sensing is with a sense resistor. The voltage drop across a known low value (couple ohms max) power resistor can be fed into an amplifier (if need be) and then a comparator and set to trigger at whatever current value you want. Simple active constant current devices work much the same way, only without the comparator. You need to supply a lot more details about exactly what you're trying to achieve and describe and preferably post schematics for any circuits you're using.