Abstract: A voltage converter has a control circuit that generates a PWM voltage from a DC input voltage, a housekeeping coil and a first voltage rectifier-filter which supply power to the control circuit from an induced voltage in the housekeeping coil, and a second voltage rectifier coupled to the housekeeping coil to rectify flyback (or reset) voltages in the housekeeping coil. The rectified flyback voltage controls the frequency of the PWM voltage generated by the control circuit. During an overload, the control circuit reduces the duty cycle of the PWM voltage. In response, the magnitude of the rectified flyback voltage falls which causes the frequency of the PWM voltage to be reduced. The first and second voltage rectifiers may be coupled to different taps of the housekeeping coil, so that both voltage rectifiers provide positive voltages relative to a ground tap even though the two voltage rectifiers rectify pulses of opposite polarity on the secondary coil.