Analysis of LED lighting fixtures and sensor technology 6

Temperature sensor for over temperature protection of LED lighting fixtures

The temperature sensor NTC has been widely used for over temperature protection of LED lamps for a long time. If high-power LED light sources are used in LED lamps, multi wing aluminum heat sinks must be used. Due to the small space of indoor lighting LED lamps, heat dissipation is still one of the biggest technical bottlenecks. If the heat dissipation of LED lamps is not satisfactory, it will cause early light decay of the LED light source due to overheating. After the LED lamp is turned on, the heat will also accumulate towards the lamp head due to the automatic rise of hot air, diode affecting the lifespan of the power supply (Figure 9). Therefore, when designing LED lamps, an NTC can be closely attached to the aluminum heat sink near the LED light source to collect the temperature of the lamp in real time. When the temperature of the aluminum heat sink of the lamp cup rises, this circuit can be used to automatically reduce the output current of the constant current source to cool down the lamp; When the temperature of the aluminum heat sink of the lamp cup rises to the limit setting value, the LED power supply is automatically turned off to achieve over temperature protection of the lamp. When the temperature drops, the lamp is automatically turned on again (Figure 10).diode

Figure 9: Heat accumulation phenomenon of LED lamps

Figure 10: NTC over temperature protection scheme

Conclusion

Because LED lighting fixtures are complete electronic products, with the diversification of LED lighting fixture structures and the expansion of applications, and with more creativity and innovation in LED lighting fixture design, more sensors will be combined and applied in LED lighting and lighting engineering systems. A new era of intelligent LED lighting is coming, and human lighting life will become increasingly bright and comfortable.diode