Fluorescent Lamp Driver. Heatsink is required for MOSFET Q1 to prevent over heating and keep the component in good performance. It is better to use transformer with 240V primary and 10V secondary, but that kind of transformer is little hard to find.
IRF510 power MOSFETs is designed for applications such as switching convertors, switching regulators, relay drivers,motor drivers, and drivers for high power bipolar switching transistors requiring high speed and low gate drive power. These component can be operated directly from integrated circuits (IC).