Why does my recess can light cycle on and off after I put a larger wattage bulb in?

Modern Recess Cans are rated for a maximum wattage bulb and are equipped with a thermal device that does not allow a bulb larger than that rating. If a larger wattage bulb is used, as the excess heat builds up, the thermal device will shut the can off until it cools. This is a safety device to protect your home against fire.