I'm learning negative feedback topologies and am stuck on current-series and current-shunt. I can't find examples of simple circuits to help me understand their function. All I can find is block diagrams but I'm looking for simple op-amp or BJT circuits that I can learn from (like when I used inverting and non-inverting opamps to learn voltage-controlled feedback). What is the simplest circuit using current-controlled negative feedback possible?
I read somewhere (apologies, can't find it now!) that a common emitter can show both these topologies. A resistor from collector to base can show current-shunt and the emitter resistor can show current-series. But how do these circuits match up with the block diagrams? What parts of the circuit get included in the amplifier and feedback network boxes in block diagrams?