Rotation 3: Soldering - wrafab/taor GitHub Wiki

In this rotation we covered soldering. For the soldering part, we finished three projects: the first one is a voice controller with the LEDs of different color that measures the loudness. The schematics is as follows:

As we can see, all the LED are connected to the integrated circuit on one end and the capacitor C1 on the other end in parallel. The integrated circuit controls whether each LED goes on or off, while the sound sensor will change in resistance according to the loudness and thus change the voltage that enters the integrated circuit. The IC then decides based on the voltage how many LED should light up.

Unfortunately, due to my bad soldering, the sensor does not work, but the real product is here:

The second soldering project we did was the LCD clock encased in a plastic chamber.

The product is here.

In the circuit, the photoresistor and the thermistor respond to change in light and temperature with change in resistance, which will in turn change the voltage in the integrated circuits. The IC then recognizes the changes and calculate out the value for temperature and brightness. The integrated circuit is a electric circuit that is packed tightly into a microchip. Since there are many transistors, the circuit could regulate the output voltage to each pin. In this project, IC controls to four LCDs to display different numbers.

Finally I did Surface Mount Soldering with 1206, 805, 603, and 402. Although the resistors are fairly small, I learned to melt some solder on one of the legs and then attach it to the base so that when I solder on the other leg it is stable and easier. The tweezers also helped a lot with the process. The picture is as follows: