Sept 4-Electricity

Introduction:

In this lab, we were learning how to create basic circuits on a breadboard, use multimeters, read resistors, and use a potentiometer.

Procedure:

In the beginning, we tried using a battery to power our breadboard, but after testing it, we realized that the battery was not putting out the right amount of voltage. So instead of using the battery, we decided to use the arduino. Next, what we needed to do was use the multimeter to ensure that the arduino was indeed putting out 5 volts. We did this by touching the leads on the multimeter to the wires that were plugged in to our arduino. Through following these steps, we confirmed that the arduino was putting out the right amount of power.

Next, we started to form our circuit. We user a Resistor Color Code Chart like the one above to calculate how much resistance each resistor gave so that we could make sure that our LED would be getting enough, but not too much power. We double checked our suspicions with the multimeter to make sure that our calculations were correct. It took a few tries to get the right resistor, but eventually we were successful.

To make a serial circuit, we plugged the red wire in to the arduino and then plugged that in to the first column on our breadboard. That supplied power to the first row. From there, we ran another read wire to the row where our resistor started. On the row where our resistor ended, we placed the LED’s. Then, we plugged a blue wire from the row with the LEDs to a higher row. From there, we plugged in a white wire that connected to our ground column, which was then connected via black wire back to our arduino. Really, we did not need the blue wire-we could have plugged the white wire directly from our LED row to our ground column.

Before power

After power

Next we decided to make a parallel circuit. Starting with our already completed serial circuit, we added a switch on the row with the read wire and first resistor. This switch was so that when the button was pushed, our second resistor would receive power. This second resistor ran to another row that had two more LEDs and a yellow wire. This yellow wire ran from the LED row back over to the row with the blue and white wires, completing that side of the circuit.

Before button pushing

During button pushing

Ideally we were hoping to design a circuit that would allow the first set of LEDs to be on when the button was not pushed and then the second set of LEDs to turn on while the first turned off when the button was pushed. However, we were informed that we did not have the materials on hand to complete this type of circuit.

Next we learned how to use the potentiometer. With the potentiometer we created a very simple circuit with only one LED. With the breadboard still connected to the arduino in the same way it was before, we connected an orange wire from the power column on the breadboard to the potentiometer to supply it power. Next, we connected the brown wire from the potentiometer to the ground column to provide ground for the potentiometer. Finally, we connected the green cable to the row on the breadboard that contained the LED and the white cable that was providing ground for the LED circuit. We did not need to use a resistor as that is what the potentiometer does. The potentiometer allows the resistance to be change with the twist of the knob on top.

Our circuit with the potentiometer

Conclusion: 

In this lab I learned a lot about how circuits work. Also, I had heard the term multimeter numerous times before, but had never actually used one. This lab was a good chance to be able to. I gained a lot of hands on experience that I think will help me in the future both in this class and hopefully in the real world (It also reaffirmed in my mind that my lab partner can’t follow instructions. At all. Ever.)