Difficulties We Encountered

Even though we thought that building a laser communicator would be fairly easy as long as we understood how each part in our circuit worked, the process turned out to be much more complex than we initially thought. One of the most challenging parts in our project was that the op-amp would not amplify the voltage even though the circuit was accurately set up; rather it decreased the input voltage. When we finally achieved the desired amplification of the voltage, another question rose. That is, after adding a small resistor between the op-amp and the base of the transistor, the laser beam became dimmer than usual, and we were not able to achieve the intensity as strong as what we got in the beginning. Hence, we removed the resistor between the base and the op-amp and replaced it back with a simple wire. Yet the light did not get stronger but dimmer as when we used the resistor. Then we repeated with the resistor again. It got even dimmer! In the end, we created a new breadboard with new materials including the op-amp and the transistor using the same set up as before (without the resistor). Then, it finally worked again.