A system for controlling the temperature in an electrical component. The power dissipation of the electrical component is measured and compared to a desired power dissipation. In case the measured power dissipation differs from the desired power dissipation a signal, preferably a signal having an energy outside the region of normal operation of the electrical component, is injected into the electrical component in order to control the power dissipation and thereby the temperature of the electrical component. May also be used for controlling the temperature of another component positioned in the vicinity of the electrical component, e.g. an optical component, such as a lens. Advantageous because a separate temperature sensor is avoided. Suitable for use in an optical disk drive, in particular for blu-­ray disks.