Patent ID: 8242757

Claim:
A constant power control apparatus, for providing output power to a load element, the constant power control apparatus comprising: a compensation and modification device, for receiving an expected output power voltage and a voltage feedback signal relating to the output power, wherein the compensation and modification device transforms the expected output power voltage into a current reference value, and modifies the current reference value to generate a modified current reference value according to the voltage feedback signal; a constant power control device, for receiving the modified current reference value and a current feedback signal relating to the output power, and generating a control signal for adjusting the output power; and a power generation circuit, for receiving the control signal and outputting the output power; wherein the compensation and modification device comprises: a first error amplifier, for generating a voltage modification value according to the voltage feedback signal and a voltage standard value relating to the load element; a gain controller, for imposing a gain on the voltage modification value and generating a voltage gained value; and a second error amplifier, for generating the modified current reference value according to the voltage gained value and the current reference value.