Hi all.
I'm trying to use a differential amplifier for high side current sensing in my bench supply, loosely based on Dave's series of bench power supply videos.
Here's my simulated circuit. Works more or less as expected.
In my real circuit...
Op amp is a KIA358P (LM358 clone) which in the datasheet says the output should be able to swing to ground.
One side of sense resistor is at ~16.7 above ground
The other side is at ~16.3 above ground
Resistors are 10k (actually 9.73k, matched to within .01k)
I expect to see ~.4 volts at the op-amp output; I actually see ~.7.
What's going on here then?
Any help appreciated