PWM Dimmer Circuit and Driver Open Source Development

GrowLightResearch

Well-Known Member
I will be testing some various ways to drive strips of LEDs.
I recently tested some Bridgelux Gen2 BXEB-L0560Z-30E2000-C-B3 strips.
Driving them in parallel created unbalanced currents in the strips.

So I am look at alternative driver circuitry.
I was thinking an expensive high efficiency CC driver powered by a single DC power supply
The parts cost would be less than $2.00. Fabrication would take that cost up to the cost of a Mean Well LDD-H.

What I think is needed is an inexpensive PWM generator to dim LDD-H drivers.

You may be familiar with the NeoPixel RGB LED strings
https://www.amazon.com/Adafruit-NeoPixel-Digital-Weatherproof-LED-1m/dp/B00R5CBOWY/ref=sr_1_2_sspa

What I plan to do is use a similar circuit but instead of driving RGB LEDs I would use a similar driver chip to dim three LDD-H drivers.

I am trying a Texas Instruments TLC5973 3-Channel, 12-Bit, PWM Constant-Current LED Driver with Single-Wire Interface. With these I can dim an unlimited number of PWM dimmers controlled by a very inexpensive µController. (e.g. AtTiny 417)

This is not a commercial endeavor. I do not sell anything. This will be an open source project.

µController Schematic with Linear 48v to 5v power supply, high efficiency switcher step down 48v=5v power supply, USB/serial port.
schematicPWM.jpg
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PWM Schematic

schmatic3channelPWM-TLC59731x9.jpg


High Efficiency Driver Schematic
driverSchmatic.jpg

Driver Layout
driverLayout.jpg


Current Balancing Schematic

Schematic.jpg



Development PCB Layout

developmentTestPCB.jpg
 
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