Patent ID: 7132802

Claim:
In a power supply system comprising a rectifier, a converter, and a smoothing capacitor, wherein the rectifier has a first system-side input that is periodically connected to and disconnected from an AC voltage supply, a method for varying the power consumption of a load coupled to the smoothing capacitor, the method comprising the steps of: a) creating a current path that bridges the smoothing capacitor during periods when the rectifier circuit is disconnected from the AC voltage supply; b) charging the smoothing capacitor via the converter during periods when the first input of the rectifier is connected to the AC voltage supply and until such time as a voltage across the smoothing capacitor reaches a predetermined maximum value; and c) providing a control element operable to detect the voltage across the smoothing capacitor and to selectively connect and disconnect the current path, wherein the control element is coupled to a second input of the rectifier via a first resistor and a second resistor.