Figure 2.

The flyback converter voltage v boosts battery voltage V_batt = 18 V, yielding V_CC = +40 V (Erickson and Maksimovic 2004)

R1 = 5 Ω, R2 = 5.7 kΩ, C3 = 1 nF, R3 = 5 Ω, R4 = 0.05 Ω, R5 = 100 kΩ, R7 = 30 Ω, R8 = 10 kΩ, C7 = 1 nF, V_CC = 2.5 V*(R9 + R10)/R9, R10 = 1.5 MΩ, R9 = 100 kΩ for V_CC = 40 V, C1 = 47 μF, C2 = 0.1 μF. C6 = 47 μF, D1 = BZW50–100B, Q1 = MOS-FET K2256. V_batt= 18 V, V_CC is 40 V.