Second, MR16 has a large electrolytic capacitor after the rectifier bridge, which is equivalent to the load of the electronic transformer from the original pure group load to a large capacitive load.
Third, in a 5W application, a capacitor larger than 487 (uF) is required for the Buck circuit to work properly. Such a large capacity capacitor is not possible in a very demanding MR16 lamp cup.
Fourth, the output voltage of the electronic transformer is not a sine wave. It is a triangular-like wave with a minimum of 5.6V. If the working voltage cannot reach 5.6V or lower, a larger filter capacitor is needed, otherwise the LED output current will be lower at VCE. When the chip's operating voltage drops to zero, there may be a low frequency flicker of 100 Hz or a regular flicker of the time interval determined by the peripheral components of the IC's COMP pin.
In view of the current situation of the above industries and the reasons for the flashing, we recommend the RICHTEK8479 solution, which is a Two-StageTopology (Boost+Buck) architecture, and has a wide operating voltage of 4.5V to 36V, which can easily solve the flash phenomenon. Achieve stable output current and illumination.
The power scheme adopts a 2-stage architecture, that is, after the voltage input from the electronic transformer is subjected to fast recovery rectification, the voltage is boosted, the voltage is raised to a constant voltage of about 20 V, and then passed through the second-stage circuit, and The buck conversion is performed in a step-down constant current mode to keep the output current constant over a certain output voltage range.
Since the IC has two MOS tubes built in, the peripheral circuit is compact and simple, and since the scheme adopts a boosting structure, the input terminal does not need to use a large-capacity electrolytic capacitor to stabilize the input voltage, which is very suitable for application in the MR16 base, etc. Space is small.
This power supply can achieve a good constant current effect from a wide input voltage range of 8V to 19V, regardless of AC or DC input status. LED-MR16 spotlights will replace the halogen spotlights. The electronic transformer-driven power supply solution for the M7-MR16 spotlight explores a way to achieve a very compatible drive power supply.
In order to meet customer's request for UHD led Screen, PRIVA LED developed the complete solution from Module, HUB card and high precise cabinet.
PRIVA LED's PV series of UHD Led Screen has functions:
1,600mmx 337.5mm cabinet which is easy to get 16:9 Ratio of Led screen panel
2,Front installation& front maintenance. Modules, Hub card, Power supply and Receiving card all could be take off from front side and installed from front.
3, PU series of PRIVA LED has option of Power Redundancy. If one power supply defected, the other one will continue working without problem.
4,Signal dual backup
5, Smart module with calibration data. Calibration data will be saved in the module, so when replace module, the calibration data will be automatically updated.
If more information is needed about our UHD led display screen, pls feel free to contact with us!
Small Pixel Pitch Led Screen--PV Series
UHD led Screen, High definition LED screen, Small pixel pitch Led Screen
Shenzhen Priva Tech Co., Ltd. , https://www.privaled.com