A lighting device with a drive device for dimming light-emitting diodes. The drive device comprises a dimming component that operates a switch in response to both a change in an input power signal and a system temperature. In one example, the dimming device can include a waveform generator that generates a signal with a waveform having levels that change in response to changes in temperature. The waveform defines the time during which the switch is open and closed, thereby determining the period of time the LEDs are energized. By operating the LEDs in this manner, the drive device effectively dims the LEDs to reduce the operating temperature and cool the LEDs.