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ruzfactor said:It's awesome! LEDs are very bright!!! I've used 100ohms as resistance to connect the 3 LEDs in series. I have a dumb question to ask: Can I connect the LEDs to +12V instead of +9V? Will it burn out the LEDs?
To audioguru: I have 100 ohms and after that I have 220 ohm resistors. Don't have any 150 ohm.
ruzfactor said:calculation showed that I should use 345 ohm for +12V. So Can i use 320 ohms?
ruzfactor said:At 440ohm and 12V , my LFR worked well. I think too much illumination makes it hard to tune the comparator with POT.
ruzfactor said:hi ericgibbs,
I need to clear another thing. I'm a bit confused. Two resistors are used as voltage divider in the comparator at the inverting I/P. Now I my question is that do I need to use the same value of resistors for both Comparators I'm using?? I have used two 57K resistor for the first comparator and two 27K for the second comparator. Plz clear me out.
ruzfactor said:Actually I have connected like this schematic. Please check it. For Both inverting I/Ps i get about 2.9~3.0 Volts (I'm using +6V instead of +5V). Is it necessary to use same values of resistors for both comparators?
ruzfactor said:I don't have any details on this LFR project except the circuit diagram. But the LDRs should be positioned like this pic. Assume the red dots as LDRs. Also the I/P voltage should be tuned to the voltage close to the Ref. voltage at start.
ruzfactor said:hi,
Track background is black and two 470ohm used for the two LED series.
At first I tune the pot to set the Input voltage(2.9~3.05V) close to Reference voltage (which is around 3V). When No light is detected, I/P voltage becomes about 3.4~3.5V. And when the LDR directly comes below the white tape, the I/P voltage becomes very low(around 1.17V) and slight displacement would make it vary between 1.85~2.4V.
Plz correct me if I'm wrong: when V I/P is less than V ref then the O/P is LOW
When V I/P is greater than V ref then the O/P is HIGH.