I would like to finally make drivers for my flashlights. Recently, I found some time to play with them. But now I think I’m obsessed with good modes spacing.
Out of curiosity, I made an excel chart of PWM values for 1xAMC, allAMC and FET. I have drawn the average value for each mode.
Shouldn’t average value be more smooth?
From what I remember about programming, the value of PWM is logarithmic. And the PWM value in the chart below is more linear.
Marked orange line as it should look to me.
It seems to me that PWM values should be improved in BistroHD.
What do you think about this?
errm you need to add the currents of the 3 channels
of yourse each channel looks like not so good
you took the average, but not into account that the channels got different currents, so 6 AMCs count 6 times more than one
one hint would be that the 100% FET in your chart is counted as 85/255 average, that you are doing something wrong
and the FET depends on hor many and which LEDs you got, as example lets take a triple with 12A
so the FET draws about 5 times mre than all AMCs
now taking 1 AMC as base value you got to multiple the AMC bank with 6 and the FET with 30
then do the average
in low PWM cycles it becomes even worse as the AMCs do not regulate liear to the PWM duty cycle, they fade out and when the FET has a fairly hight PWM cycle it simply bypasses the AMCs so their effective output current decreases
and for level 16-18 usually people want not 100% FET so more like 30 and 60% makes sense over logarythmic curve
Thanks Lexel for a great explanation. I am impressed by your knowledge. For me, it’s still a bit of black magic.
Can you tell me if it is better to connect channels at higher levels 16-19, or it’s better to use only FET? From what I understand, FET only is better.
