Hi,
I'm trying to design a simple self-monitoring circuit that will cut off the supply to a (time-varying) load when the current through it drops below a threshold value.
I have a vague idea that I should use a comparator circuit, but I'm not sure how to implement it.

A few more details:
Load voltage: ~3 V
Load resistance: Initially ~100 Ohm then increasing to essentially open circuit after a few minutes.

Response time should be a few milliseconds.

Thanks!