But form general testing I still have a question about the behavior of the screen dimming feature. Because when attaching the light sensor and changing the light conditions for the sensor, the display dimming doesn't always reactor only with a delay. Often I also noticed that, when covering the light sensor, the display wouldn't dim, even when waiting for a few seconds. But when I then uncover the sensor for a brief moment and the cover it again completely, then the display dimming reacts. I tried to capture it in the video attached. 

 

Is there some issue/function that the display doesn't dim, if the light conditions change to quickly? I know in reality the light conditions don't usually go from very bright to completely dark, but there might be similar conditions, when suddenly a cloud covers the sun or if someone or something is blocking the light sensor from the light. 

 

 

Here is another example video, where at the beginning it doesn't dim down when covering the light sensor. Only when opening my hand (more light) it starts to dim down the display. 

 


Answer:



 So after all the range of brightness using the light sensor is from 15%-100%, not 30%-100% as you wrote in your original email, correct? 

>>Yes the 30% is a typo. the PWM range of the KELS-003 is 15% to 100%.

So when it's completely dark, the brightness is set to 15% and and when it's bright sunshine it's set to 100%, right?
 

the PWM output of the KELS-003 will be 15% when dark and 100% when bright, but please note that some LED driver will “limit” the minimum current output. For example the LED driver may only set to 40% of the current for its lowest level.

With regards to the analog output you write that the "LED driver will generate a proportional output current." But then you mentioned something about 1.5V at 50%, which is a voltage.
So did you mean that the LED driver for analog output will generate a certain voltage (not current) proportional to the brightness level input from the light sensor?


the analog diming using the voltage level as a dimming signal, while the LED brightness is controlled by the current value. So the voltage signal from the KELS-003 will eventually affect the output current of the LED driver. Sorry for the confusing wording and to be clarify, either PWM or analog signal is an output of KELS-003, also as input signal to LED driver. The LED driver will adjust the current value to LED strips based on the analog or PWM signal.

Yes, the cable length will for sure be an issue as it might cause a voltage drop, which will affect the accuracy of the signal. The PWM signal should be more robust for sure, but it also introduces more noise in the system as it has sharp edges. 

 

But to test it out, what would be the easiest way to access the PWM output signal? Where is the KELS-003 controller PCB located in the enclosure? Is there a way to easily access that connector with the PWM output signal or another point in the system, where we could access the PWM output signal? 

>> unfortunately the PWM signal from KELS-003 is not possible access from outside of the enclosure. The PCB is next to AD board as below figure. CN4 is the PWM output and you could find the detailed characteristic in the attached spec. 


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