A method of controlling a ballast in a circuit for a lighting application and connected to a mains power supply is disclosed. The method comprises determining whether a dimmer is present in the circuit; in response to detecting that a dimmer is present, determining a zero-crossing of the power supply and setting a bleeder current through the ballast in dependence on the phase of the power supply within a mains half-cycle; and in response to determining that a dimmer is not present, disabling the bleeder current. A ballast which is controlled by such a method is also disclosed. Additionally, a controller, which may include a digital signal processor, for a ballast and operable according to the above method is disclosed.