27 Mar 2003 rsbohn   » (Observer)

Got my LP339M samples in the mail: 4 low power comparators in a 14 pin SOIC narrow package. Wasn't sure it would be possible, but I managed to free-form a light seeker circuit right on the tiny chip. I ganged the comparators so I could sink more current (hope for 60 mA) on each side. I used 2 220K resitors for a voltage divider and two LDR's for the light detectors. After several retries I had the circuit assembled. I plugged it into the solderless breadboard, connected a limiting resistor and two LED's. No smoke! Unfortunately my LDR's weren't balanced, I had to embed one of them in clay to make the circuit work better. Blinkenlights! Just waving your hand in front of the sensors will make it switch side to side. I think this circuit would be fine for a simple light tracking headbot. Hope to post some pictures soon.

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