An electronic ballast powers at least one fluorescent tube or lamp which has a power source; a DC power supply having an input connected to the power source; an oscillator connected to an output of said DC power supply so as to be driven therefrom; a driver means; and a protection means that deactivates the oscillator when the output reaches a predetermined abnormally high voltage. The protection means includes a transformer; a plurality of windings disposed on the transformer, a delegated winding disposed on the transformer. The protection means includes a sample point for sampling voltage. The protection means deactivates the delegated winding disposed on the transformer for the magnetizing the transformer and stopping oscillation when the sample point reaches a predetermined abnormally high voltage.