Part 1 of a readable two-part, no-nonsense ramp-up into the very depths of control loop theory -- from Sanjaya Maniktala, reputed author of over six well-known books of power electronics. Go confidently from the mundane world of closed loop room air-conditioners, into the heart of modern switchers. Featuring a deep dive into finer aspects of analog and digital control, routinely glossed over in related literature, or mystified by unending math. Corrects abundant myths, preconceptions and erroneous notions to prepare the stage for a unique understanding of PID coefficients, never before conveyed in such a straightforward and elegant manner.