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Author Topic: How does this circuit look for PWM'ing 40 RGB LED's?  (Read 1159 times)
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I am putting together a house lighting project using RGB's, my plan is to use a TLC5940 driving 5 RGB LEDS (15 PWM's), and multiplexing 8 LED's onto each channel, giving 40 total RGB LED's with this setup.  I would like anyone with much better expertise then my own as to if the circuit I designed is adequate enough.  I did breadboard the design with 4 multiplexed LED's per channel and it seemed to run fine (though I will probably have to use dot correction for best results...).  Note that the schematic is not complete, I did not bother at this point to fully schematic out the 595 and 5940's power, ground, and arduino connections, but the schematic for the LED's is there.  I am biasing the 5940 for 40ma per channel considering how fast the multiplexing is happening to get a good brightness (I could go to 60ma but I will be taxing my available power supplies doing so).

I am not sure either about the best placement of capacitors for power smoothing, as I noticed with the scope that the switching or PWM is not as clean as it should be, so any ideas on that would be great too, thanks!

Schematic:
http://www.digikey.com/schemeit/project/a4g/LED-Project


* LED-Project.png (84.57 KB, 1186x829 - viewed 56 times.)
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Here is a video demonstrating my circuit, been running for about an hour now and all components involved are as cool as when I pulled them from the parts drawer, so I think it works however any ideas are still welcomed!

« Last Edit: October 10, 2012, 01:12:40 pm by MatCat » Logged

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Wow 51 views and not a single reply!
Got to tell you something about your previous behavoure then.
Excuse me?
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