An ac-dc power supply comprising an input configured to be coupled to receive an ac input voltage (104, 404, 504) and an ac input current (102, 402, 502), comprising: a rectifier coupled to the input of the ac-dc power supply (100, 400, 500, 600, 700), wherein the rectifier is coupled to provide a dc input voltage and a dc input current; a flyback dc-dc converter coupled to the rectifier such that the rectifier is arranged to provide the dc input voltage and the dc input current to the flyback dc-dc converter, wherein the flyback dc-dc converter includes a regulated output (146, 144, 446) connectable to a load (148, 448), and a reservoir output, wherein the flyback dc-dc converter includes i) an input primary winding (420, 520, 620, 720), ii) a first output winding (424, 524, 624, 625, 723) coupled to provide power to the regulated output, and iii) a second output winding (422, 522, 622, 725) coupled to provide power to the reservoir output; a controller (162, 462, 562, 763) coupled to receive sense signals from the flyback dc-dc converter, wherein the controller is coupled to control the flyback dc-dc converter to regulate the regulated output (146, 144, 446) for the load (148, 448) in response to the sense signals, wherein the controller is further coupled to control a waveform of the ac input current to have substantially the same shape as a waveform of the ac input voltage by switching a primary switch of the flyback dc-dc power converter such that the ac input current is proportional to the ac input voltage by a factor that is substantially fixed throughout a half line period but adjusted each half line period in response to a difference between the regulated output and a desired value; and a regulator circuit (140, 440, 540, 640, 740) coupled to the regulated output and the reservoir output, wherein the regulator circuit includes either a linear power converter or a switched mode power converter, wherein the controller is coupled to the regulator circuit to control a transfer of energy from the reservoir output to the regulated output through the regulator circuit during portions of the line period when the instantaneous input power is less than the demand of the load. a rectifier coupled to the input of the ac-dc power supply (100, 400, 500, 600, 700), wherein the rectifier is coupled to provide a dc input voltage and a dc input current; a flyback dc-dc converter coupled to the rectifier such that the rectifier is arranged to provide the dc input voltage and the dc input current to the flyback dc-dc converter, wherein the flyback dc-dc converter includes a regulated output (146, 144, 446) connectable to a load (148, 448), and a reservoir output, wherein the flyback dc-dc converter includes i) an input primary winding (420, 520, 620, 720), ii) a first output winding (424, 524, 624, 625, 723) coupled to provide power to the regulated output, and iii) a second output winding (422, 522, 622, 725) coupled to provide power to the reservoir output; i) an input primary winding (420, 520, 620, 720), ii) a first output winding (424, 524, 624, 625, 723) coupled to provide power to the regulated output, and iii) a second output winding (422, 522, 622, 725) coupled to provide power to the reservoir output; a controller (162, 462, 562, 763) coupled to receive sense signals from the flyback dc-dc converter, wherein the controller is coupled to control the flyback dc-dc converter to regulate the regulated output (146, 144, 446) for the load (148, 448) in response to the sense signals, wherein the controller is further coupled to control a waveform of the ac input current to have substantially the same shape as a waveform of the ac input voltage by switching a primary switch of the flyback dc-dc power converter such that the ac input current is proportional to the ac input voltage by a factor that is substantially fixed throughout a half line period but adjusted each half line period in response to a difference between the regulated output and a desired value; and a regulator circuit (140, 440, 540, 640, 740) coupled to the regulated output and the reservoir output, wherein the regulator circuit includes either a linear power converter or a switched mode power converter, wherein the controller is coupled to the regulator circuit to control a transfer of energy from the reservoir output to the regulated output through the regulator circuit during portions of the line period when the instantaneous input power is less than the demand of the load.