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Will the CRI change when the LED Strips are dimmed?
If I reduce the brightness of a LED strip (dimming) will be the CRI the same as before? Or the CRI is a constant value, like a feature or how to define, a "passive skill" so does not matter that I reduce a 20W LED strip consumption to 10W and reduce the brightness highly, the CRI will stay constant, and the same as before?
When LED strip lights are dimmed via PWM, the LEDs are pulsed "on" and "off" at a very rapid rate. During the "on" phase, the LEDs will exhibit the same color and spectral properties as when the LEDs are at full power. During the "off" phase, the LEDs are completely turned off.
With PWM, various brightness levels are achieved by adjusting the ratio of the time between the "on" and "off" phases (aka PWM duty cycle). Since the quality of the light during the "on" cycle remains the same regardless of the PWM duty cycle, we also see that the CRI value will remain constant across the dimming curve.
What if I use another dimming way, like resistance with a potentiometer? So when we control the current or voltage they will get, then what does happen with CRI? If so, then the only good way is PWM, but does PWM work only with a PWM receiver or can it work without a receiver?
If you are looking to implement your own dimming solution, using a potentiometer or voltage splitter can be an option. With high-power LED strip light installations, however, this is known to be tricky due to the high amounts of energy that must be dissipated. (This is why PWM is usually the preferred method for dimming in high-power LED installations).
For an example of a PWM dimmer, please see our inline dimmer product below:
If you were to reduce the brightness of the LED using current or voltage reduction, you may see some changes to CRI. Based on the data I have seen, however, the changes are typically in the 1-2 point range and are not significant.
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LED strip lightsLED dimmers