Design of LED Lamp with special spectral characteristics

The goal of this work is the design of LED lamp with adjustable spectral characteristics. The spectral power distribution (SPD) of the lamp can be adjusted to imitate the SPD of the daylight at noon and at evening. Noon light is “bluish” and stimulates cognitive abilities, work productivity and attention; sunlight at evening doesn’t inhibit melatonin production leading to improved sleep during the night and better health. Special combinations of LEDs with different spectral and power characteristics and proper control of the LEDs’ operation are used to achieve the required spectral characteristics of the lamp. Thermal management investigations are made at various ambient temperatures ranging from 20ºC to 45ºC and different current values through LEDs – up to their maximum values. They allow determining safety operating conditions for LEDs depending on the ambient conditions

LED LAMP FOR APPLICATION IN MEDICAL CENTERS – DESIGN AND THERMAL MANAGEMENT

The goal of this work is research and development of light sources suitable for use in hospitals, nursing homes, hospices and other similar institutions. During the day spectral power distribution (SPD) of this type luminaire needs to simulate natural day light that affects the natural circadian rhythm of humans. Maintaining the natural circadian rhythm impacts positive on human health, improves mood, prevents the development of depression and helps to overcome them. In the late afternoon increase light in the red-orange part. Light of this kind of spectral composition doesn’t inhibit melatonin production and the human body naturally prepares for rest and sleep. At night artificial lighting should be in the red - orange area to enable patients to sleep and staff to fulfill their obligations. Theoretical analysis and selection of suitable LEDs for the realization of the luminaire with the desired characteristics are made. Performed experimental studies make possible achieving the desired characteristics of light and appropriate LEDs’ modes of operation