Patent ID: 7609037

Claim:
A power converter having an input voltage and an output voltage comprising: a buck derived power modulator in series with a variable dc-dc transformer power modulator, the power converter having a normal mode for operation when the input voltage is in its normal range the power converter having an over voltage mode for operation when the input voltage is above its normal range, and the power converter having an under voltage mode for operation when the input voltage is below its normal range, when the power converter is operating in the normal mode, the buck derived power modulator is saturated, the variable dc-dc transformer power modulator is nearly saturated and voltage regulation of the output voltage is accomplished by varying a ratio control input of the variable dc-dc transformer power modulator; when the power converter is operating in the over voltage mode, the variable dc-dc transformer power modulator is saturated and voltage regulation of the output voltage is accomplished by varying a duty cycle control input of the buck derived power modulator, and when the power converter is operating in the under voltage mode, the buck derived power modulator is saturated, and voltage regulation of the output voltage is accomplished by varying the ratio control input of the variable dc-dc transformer power modulator.