In the first part, uncompensated and unstable polynomials from 2nd order to 10th order are mentioned and it was also concluded that control loops are unstable, the change in coefficients could be seen in the list. In this part, rather taking such unpractical or impractical circuit (or novel B circuit or novel B-topology), a practical ‘buck-boost’ known circuit and its stability has been explored. The known working circuit is assumed as a black box and is declared as  equipment under test (EUT) with just input and output and the control loop stability would be investigated using compensators. The author examines the stability and analyses how the abyss of coefficients change with respect to different compensators when the MOSFET switching frequency is changed from 50 Hz to  1.999 MHz or 1999 kHz.

Due to large number,this paper studies the abyss of stability and unstability, the game of coefficients, upto third order polynomials. The Bode plots of the compensators designed with P, I, PID, series PI, parallel PI, One pole one zero (1P1Z), multipoles, two pole two zero (2P2Z) and three pole three zero (3P3Z) are submitted. The known theory is also explained as summary.

This paper is also the transcript of the proposed invited talk as speaker in some conference.