When lighting is more than just lighting

LED drivers for quick, easy integration of human centric lighting

The tuneable LED drivers in the LCM-40TW series allow the colour temperature and brightness of white LEDs to be controlled easily and independently, enabling the creation of an intelligent, human-centred lighting environment: ''human centric lighting.''

The problem

It is known that ambient lighting affects human biorhythms. Whereas cool white or neutral white light with a higher proportion of blue supports concentration and productivity, warm white light is preferable shortly before bedtime or when resting. LEDs can provide a wide spectrum of visible light and thus different colour temperatures, as required. At the same time, human centric lighting concepts need circuits that not only provide sufficiently bright light but also regulate the colour temperature without undesired changes to the brightness.

The solution

Dual-output LED drivers with digital lighting control replace the complicated control methods previously needed with a downstream DT8 dimmer. One example of such an LED driver is the digital LCM-40TW driver from MEAN WELL. The power supply has an IP20 plastic case and offers an input voltage range of 180 - 277VAC, protection class II, and DALI-2 or push-button dimming. It allows adaptation to different customer-specified LED modules, providing two output channels for LEDs with different colour temperatures (warm and cold white). The maximum power of the two outputs is 40W. In addition, DALI DT6 can be adjusted for flicker-free pure brightness control or DALI DT8 for colour temperature control. Output current is adjustable between 500mA and 1050mA via DIP switch, while brightness and colour temperature can be controlled or dimmed across a wide range (with a minimum dimming value of 0.2%). Adjustments to the colour temperature are achieved by changing the ratio of the driver current of the two outputs. At the same time, the LED driver’s digital lighting control ensures that the colour temperature and brightness settings do not affect each other (Image 1).

Complementing the LCM-40TW, MEAN WELL's DLC-02 DALI controller and DLC-02KN KNX-DALI gateway can be optionally updated with new software for the DT8 dimming function on the MEAN WELL website.

Image 1: Control process for an LED lamp with tuneable colour temperature (Image: MEAN WELL)

Straightforward operation makes the difference

The LCM-40TW can be adapted to suit a variety of customer-specified LED modules. The colour temperature is controlled either with the DALI bus or, as mentioned above, adjusted using a push-dim button in several steps. The ambient lighting is thus easily adjusted to suit the conditions on location, or to adjust the colour temperature to particular situations or times of day – very much to the advantage of users, who benefit from improved performance and well-being.

Image 2: Schematic of intelligent DALI-2 lighting configuration (Image: MEAN WELL)

Advantages of the tuneable LED drivers:

• Brightness and colour temperature are adjusted independently of each other: this is made possible by two output channels for LEDs with different colour temperatures (warm white and cold white).

• Highly flexible: use on DALI DT6 for flicker-free brightness control or on DALI DT8 for colour temperature control.

• Consistent lighting for HCL systems: DALI synchronises the shift from one lighting scheme to another, with all light sources reaching the new illumination level simultaneously.

• Wide dimming range: The output current can be adjusted in 6 steps from 500 to 1500 mA, with a minimum dimming level of 0.2%.

• Suitable for intelligent DALI lighting in buildings: The LCM-40TW LED driver has a push-dimming function that allows users to adjust the colour temperature and brightness with a DIP switch.

Our technical sales team will advise you on the selection of suitable power supply products and on customer-specific questions on the subject of ''Human Centric Lighting''.