# Design and Application of Daylight-Based Lighting Controller on LED Luminaire
## 5 Conclusions  
This paper proposed a daylight control circuit in LED luminaire and evaluated its performance in terms of power consumption reduction and maintaining illuminance value on the working plane using both simulation and experimental setup. The simulation of luminaire performance and effect of daylighting on working plane has been done using DIALux software in the aspects of both actual room and experimental setup that replicate parts of the actual room. The simulation results have shown the effectiveness of daylight in providing sufficient illuminance on working planes in areas near the window, thus reducing the power consumption of the artificial lighting by limiting the light output from the luminaire while maintaining the uniformity on the working plane.  
In the case of the experimental setup, the proposed daylight control circuit prototypes and experimental setup for an actual field test have been built. The research has been divided into two parts: the effect of louver and effect of the time period on daylight control circuit performance in terms of both electrical and illuminance characteristics. The louver has a significant effect on control circuit performance. As a result, it reveals that with a higher louver angle, it results in high illuminance due to more daylight inlet. Thus, the control circuit reduces power to LED luminaires to maintain desired illuminance on a working plane. The effect of the time period showed that in the morning period, the control circuit reduces light output from LED luminaire. However, in the afternoon period, daylight inlet is less due to the direction of sunlight. This results in the control circuit having to operate at full capacity in order to maintain illuminance at the required value.  
Results obtained from the actual field test using experimental setup have showed the effectiveness of the proposed daylight control circuit for LED luminaire under differential conditions. It can maintain the required amount of illuminance on the working plane during the daylight condition, while significantly reducing power consumption. This has illustrated the potential of using daylighting on lighting systems to improve building efficiency while maintain lighting quality on for the occupant. So, future work can implement the proposed daylight control circuit in actual buildings to demonstrate the improvement of energy efficiency in a lighting system.  
Conceptualization, S.B. and A.N.; Methodology, A.N.; software, T.P.; Validation, C.J., and A.N.; Formal analysis, S.A.; Investigation, T.P.; Resources, A.N., and C.J.; Writing--original draft preparation, S.A. and T.P.; Writing--review and editing, A.N.; Supervision, A.N.; Project administration, S.B.; Funding acquisition, C.J. All authors have read and agreed to the published version of the manuscript.  
The work presented in this paper is part of a research project (No. A118-59-003) sponsored by the Faculty of Engineering, King Mongkut's Institute of Technology Ladkrabang Research Fund. The author would like to thank them for the financial support.  
Figure 10: Data from experimental setup over the period of one day with daylight control circuit: (**a**) Illuminance on working plane; (**b**) Power consumption.  
**Acknowledgments:** The authors wish to gratefully acknowledge the financial support for this research from the King Mongkut's Institute of Technology Laddrabang Research fund.  
**Conflicts of Interest:** The authors declare no conflict of interest.