Creating the potentiometer and LED board

CAD softwares can help create personalized circuit boards that fit the needs of your project. We practiced the process of simulating the circuit on the computer, soldering the components to a protoboard, and milling our own PCB boards by building a simple potentiometer and LED board. Below is a google drive folder with files and pictures of different steps along the way.

Breadboard:

A breadboard is a temporary version of a circuit that shows what parts of the design will work and maybe what parts need to be modified. It uses wires to connect the components, and it is easy to assemble and reassemble. Instead of working with a physical breadboard, we used Tinker Circuit to demonstrate the feasibility of the circuit we wanted to create. Because it was a simple series circuit, I didn't run into too many problems during this step. Below is a picture of the completed circuit on Tinker Circuit and a video of the simulation.

For the potentiometer and LED board, all we needed was a battery, potentiometer, slide switch, and LED plus connector wires. On Tinker Circuit, you can change the values of the resistors and the color of the LEDs, and to add a wire, you just click on an empty hole and drag. A couple things we had to keep in mind were the polarity of the LED and the direction of the terminal strips. The negative lead (straight) of the LED had to be connected to the ground and the terminal strips ran vertically. For the slide switches, we only used the second pin (in the middle), but if we had wanted to, we could have connected a second LED to the third pin and had the switch control both LEDs. It was also important that we didn't skip over the second pin on the potentiometer.

Simulation:

IMG_1306.MOV

The simulation shows that the LED does turn on when the switch is closed. In the video, you can see that when I turned the dial on the potentiometer and lowered the resistance, the LED blew up. LEDs can only handle so much current, so if there isn't enough resistance, the LED will fry. Also, when I flipped the switch, the LED turned off because the circuit was no longer complete. This gave me a good idea of how I should construct my board moving forward.

Protoboard:

Once we completed our simulation, we were ready to test our circuit using real components and solder. Our materials included a protoboard, LED, potentiometer, slide switch, and wire. When connecting components on a protoboard, there are two ways you can do it. One, you can create a solder bridge between components right next to each other, or two, you can place one end of the wire in a hole next to one of the component and the other end of the wire in a hole next to the other component and create a solder bridge between the wire and component. However, unlike a breadboard, there are no terminal strips, so none of the holes are connected. Below are pictures of the front and back of my protoboard.

Front

Back

EAGLE (PCB Design Software):

To familiarize ourselves with Eagle, we created a board with a NE555 timer, LEDs, resistors, and a capacitor. I found part 1, part 2, and part 3 of the schematic basics tutorial on the Autodesk website very helpful in this process. After we finished the schematic, we clicked file -> generate/switch to board, which opened a new page that looked quite different from the schematic. Eventually, this will become the file we use to mill the board on the Othermill.

Schematic:

Board:

MIlling:

Report abuse