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LED Driver PT4115 PWM control

Posted: Tue Sep 01, 2015 4:18 pm
by Frank607
I have a LED Driver PT4115 and a 10W LED.

This LED driver has a DIM input for controlling the brightness of the LED. I want to control this DIM pin with PWM and a 12F683 and a ADC input (trimpot)

I tried many configurations and also the standard “ADC Controlled PWM 16F88.fcf” what is in the examples folder on FlowCode 5. I read a lot of topics on this forum but the answer is not there.

I can’t get this to work smoothly with the trimpot. The LED always flicker and the trimpot (5K, 50K or 100K) is not accurate. Maybe it has something to do with the PWM frequency, I don’t know.

The DIM pin on this LED Driver can be driven by PWM or 0 to 2.5V

Can someone help me with me with a flowchart to get this to work?

Here is a link to the datasheet of the PT4115
https://people.xiph.org/~xiphmont/thinkpad/PT4115E.pdf

Re: LED Driver PT4115 PWM control

Posted: Wed Sep 02, 2015 11:15 am
by Benj
Hello,

Please can you attach your flowchart so far and we will have a look and try to make suggestions.

Re: LED Driver PT4115 PWM control

Posted: Thu Sep 03, 2015 8:50 am
by Frank607
Hi Ben,

Thanks for your answer. I quit with this PWM and use a DC voltage from 0.1 to 2.5V.

This works really smooth and have full control on it.

Thanks again.