control loops using opamp....use my linear regulator simulation in ltspice.
secret is that the opamp with neg feedback always acts to equalise the voltages on its inputs.
Also, the first 50 pages of the book by owen bishop on electronics control is good.
The sim attached
“Understand Electronic Control Systems”
by Owen Bishop
Newnes
…First two chapters, ‘introducing control systems’ and ‘control strategies’ are an excellent description of the general workings of feedback loops…this is very useful for getting a feel for SMPS feedback loops. This is at most half an hour’s reading and well worth it.