Thread: Homemade Lightwedge Project
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Old 01-30-2007, 09:47 AM   #33
obelix
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Join Date: Oct 2006
Quote:
Originally Posted by Vaporware
Ok, I'll give it a try this week. I have the instructions from the manufacturer, but I was wondering how you use the potentiometer to vary the brightness? it explains how to use a voltage divider to vary the brightness by changing the input voltage. Is that how you used the pot?
With Rset (I used 100k potentiometer, the central pin and one of the side pins are connected together; the 3 pin potentiometer becomes 2 pin variable resistor).
Schematic is the same to the one shown on the page 1 of the datasheet (except I used 2 LEDs, 2 other pins are unconnected), for the Rset vs output current see table on p.9).

http://www.fairchildsemi.com/ds/FA%2FFAN5607.pdf

I was considering also LM2703 (and even purchased one), but it requires more elements (including 10 uH coil). FAN5607 requires only 4 ceramic miniature capacitors.
Last edited by obelix; 01-30-2007 at 09:53 AM.
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