Temperature sensor NTC is widely used as over temperature protection of LED lamps. Especially the High wattage LED Stadium lights or LED  Streetlight, Due to the small space of LED housing, the heat dissipation problem is still one of the biggest technical problem at present. Poor heat dissipation of LED lamps will cause a big light decay of LED light source due to overheating. After the LED lamp is turned on, the heat will be enriched to the lamp cap due to the automatic rise of hot air, affecting the service life of the power supply . Therefore, when designing LED lamps, the aluminum radiator can be close to an NTC near the LED light source to collect the temperature of the lamps in real time. When the lamp cup is close to an NTC to collect the temperature of the lamps in real time, when the temperature of the aluminum radiator of the lamp cup rises, this circuit can be used to automatically reduce the output current of the constant current source to cool the lamps; When the temperature of the aluminum radiator of the lamp cup rises to the limit setting value, the LED power supply is automatically turned off to realize the over temperature protection of the lamp. When the temperature decreases, the lamp is automatically turned on again.