I designed a few led driver with LYT Switch-4 and LNK-PH. Designs are 40W, 50W and 60W 700mA. Each based on SCHEMATIC1.
1. Input parameters normal (THD,PF Efficiency etc)
2. Each design's output current rising 200-300mA in a few minutes. What can be do for stabilizing?
3. No load ouput voltage is more than %50 of the desired voltage. (Desired 50V, result 75-80V) Decreasing zener voltage effecting output regulation and efficiency.
4. Constant current region is very restricted. Max 7-8V. I need less than %50 max string voltage.
5. With these parameters Schematic1 is not suitable for commercial driver. Only can be used for aplication specific projects.
6. DER289 seems to complies my need. But using high valued resistor will seriously effect the efficiency. http://www.powerint.com/sites/default/files/PDFFiles/der289.pdf
7. Can I replace the sense circuit in DER289 with ST's SEA05 or TSM1052 CV/CC secondary side controller?
8. Is attached schematic CV-CC suitable for this design?