Ta: Temperature of ambient, ambient Tc: Temperature of power supply case, that is, the temperature of the surface of the triode
Ta is the best operating temperature limit of the power supply, and Tc indicates the highest temperature of the entire drive. For example, Ta = 50 degrees, meaning that life is the highest when working in an environment within 50 degrees. Every 10 degrees above, life is reduced by half. The Tc point is mainly to measure the temperature and the temperature probe attached to the Tc point.
The driver works in the ambient temperature, and housing temperature general LED driver specifications are marked with two temperatures Ta and Tc, Ta is the ambient temperature of the driver work, Tc is the maximum temperature allowed for the driver’s housing.
Ta is a temperature range, such as -40 ℃ ~ 50 ℃, the more comprehensive this temperature range means that the wider the suitable environment, usually low-temperature limit is the semiconductor’s driver, electrolytic capacitors other restrictions.
And there are two extensive restrictions on high temperature, and the first is the temperature limit required by safety regulations. For example, UL regulations Tc. Transformers, PCBs, and safety parts such as safety capacitors maximum temperature to limit the Ta. Second is the temperature limits of some electrolytic capacitors, power semiconductors, magnetic elements, and other devices.
Usually, to meet the above two requirements under the higher Ta, the lower the temperature rise, the higher the reliability of use in the same ambient temperature (internal electronic parts under the same conditions).
Usually, to meet the above two requirements under the higher Ta, the lower the temperature rise, the higher the reliability of use in the same ambient temperature (internal electronic parts under the same conditions).
Usually, to meet the above two requirements under the higher Ta, the lower the temperature rise, the higher the reliability of use in the same ambient temperature (internal electronic parts under the same conditions).
Extended information.
LED is 2 to 3 volts of low voltage drive, must be designed to complex conversion circuit, different uses of LED lights, to be equipped with LED power adapter.
Customers in the international market have very high requirements for efficiency conversion, power effectiveness, constant current accuracy, power supply life, and electromagnetic compatibility of the LED driver power supply. Designing a suitable power supply requires careful consideration of these factors because the role of the power supply in the whole lamp is as important as the heart of a person.
When using LEDs as displays or other lighting devices or backlighting, they need to be driven at constant current, mainly for the following reasons
1. To avoid driving current exceeding the maximum rated value, which affects its reliability.
2. to obtain the expected brightness requirements and ensure the consistency of individual LED brightness and chromaticity.
