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| For a bone-head exciter recipe: limit rate of rise with a long time-constant integrator; allow fast fall-time in case of overvoltage; use a free-wheeling diode; and operate the power-section switchmode, by injecting a dither at the regulator null point. Achieve this by grossly overcompensating the compensated feedback divider. Ripple at the null-point pulse-width modulates the output section at 180 Hz (three phase). Dither based PWM avoids unnecessary disipation at the output device. |