Abstract: An overload protection circuit and method for a fluorescent lamp drive circuit is presented, the fluorescent lamp drive circuit having first and second switches connected in series and a controller adapted to switch the switches on and off alternately. The overload protection circuit is adapted to detect a voltage across the first switch, and to turn off the first switch based on whether the detected voltage exceeds a first threshold voltage.

Abstract: The present invention concerns a control device (28) for a switching power converter (10), a switching power converter and a method of controlling a switch in a power converter for reducing audible noise. The power converter comprises the control device (28) and at least one switch (26) for regulating the power conversion. The control device (28) comprises a timer (45) for monitoring a switching frequency of the switch (26) to indicate when the frequency has dropped to a certain level, and a gate driving circuit (32) connected to the timer and arranged to regulate the switching of the switch in dependence of the indication from the timer, so that the frequency rises above said certain level in order to reduce generation of audible noise.