IR Sensor using lm324
I need help on the IR Sensor circuit using lm324 comparator~the distance between transmitter and receiver is 20cm.
1) How to combine both circuit together? Is the circuit design correct?
2) How to measure the output voltage when the IR sensor is in blocking condition and non-blocking condition?
The design is flawed, seriously so. You have the - input connected to gnd. This will create a anomalous condition for the op amp, which you are trying to use as a comparator. With the input at ground there can never be a cross over of the voltages. There needs to be a small resistor to raise that level off the ground, as the + input can never go below the ground level.
You have another problem in using the LM324. This is an op amp, most op amps have a problem with their inputs going near either power supply level. Using a LM393, a true comparator, is a much better choice, though don't forget the pull up resistor (10KΩ typical) on the output.
When using 4 op amps or comparators do not forget to ground the unused components inputs, to prevent unwanted oscillations.
High Speed Op Amp Query
The LM358 is an op amp that is designed for its input to go very near ground.
"Good enough is enemy of the best." An old engineering saying, Author unknown.
If you have a question, please start a thread/topic. I do not provide gratis assistance via PM nor E-mail, as that would violate the intent of this Board, which is sharing knowledge ... and deprives you of other knowledgeable input. Thanks for the verbage Wookie.
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