Thermistor reliability in LED lighting

The concept of reliability, first started in the Second World War, in the development of V-1 rocket, the Germany found the failure rate for each component directly affects the overall system performance studies. The same concept in LED lighting power supply module, the variant in which the ambient temperature will lead to lower due to the reliability of LED lamps, LED drive circuit and electrolytic capacitor used in the greatest impact on the reliability assessment.

Thermistor reliability in LED lighting

Electrolytic capacitor or even lead to the destruction of the lamp can not be used, so if the fixture can sense the ambient temperature as effectively adjust autogenous temperature LED lamp life can be extended. So, how to adjust the temperature of LED lighting applications The important issue.

The practical application of the sensed temperature, the thermistor is the most common and easy to obtain a temperature sensor, wherein the LED lighting power supply module was added as a thermistor temperature sensing application with effective and low-cost solution.

Thermistor is sintered by a hot metal oxide mixed together. Assembly formed has a resistance value varying with temperature characteristics.

Which belong to a large class of common negativetempcoefficientthermistor, referred NTCThermistor. Its resistance value will decrease as the temperature rises.

Using thermistors used for temperature sensing of the three major advantages:

1, which has a very high sensitivity. The use of high resistance thermistor sensitivity up to 10k?

2, its relatively high resistance.

3, the thermistor provide diversity of packaging components, including SMD’s small form factor packaging, even the packaging size can be reduced to 0201, as shown in FIG. In the circuit design can be easily sensed Layout in need around the heat source components.