A brushless generator with permanent-magnet multi-pole rotor disks and coreless stator winding disks includes integral electronics to efficiently generate regulated DC current and voltage from shaft input power over a broad speed range. Its power rating is scalable, and it incurs no cogging torque, or friction from gearing. Integral power control electronics includes high-frequency pulse-width-modulated boost regulation, which provides regulated current at requisite voltage over its broad speed range. A main embodiment to produce DC power at widely variable speeds includes signal processing so output power varies according to the third power of speed. A version for use with vertical-axis wind turbines has a relatively large diameter to facilitate a large number of poles. Combined boost-regulation, zero cogging torque, and no gearing, enable a wide speed range, for better power quality and higher wind energy yields. An alternate embodiment is intended to produce DC power from a variety of shaft drive sources, with selectable shaft torque.