Our 6th grade class of three was split up this week on account of scheduling conflicts. With both sessions we learned about capacitors, energy storing-discharging devices that are used in virtually all circuit boards with a variety of uses from power stabilization to signal timing. They work by accumulating charge (electrons) on two very close but separate plates which creates an energy storing electric field between the two plates. We cut up a real capacitor and found the inside to have two long coiled up foils (plates) separated by thin paper.

Monday with Magnus and Jasper we each constructed a two-bit full-adder. A full-adder is a bit of circuitry constructed with logic gates which can add binary numbers together! A two-bit adder can add two two-bit numbers together. The largest number that can be represented with two bits is three (“11” in binary) so a each circuit can count up to 6 (“110” in binary) which was represented on the circuit board as three lit or unlit LEDs. Although this math is dead easy, the circuitry to achieve this looks quite complex. Next class we will be combining each of our three circuits into a 6 bit adder which will be able to count up to 126 (“1111110” in binary).

Wednesday with Jack we explored a special three-color red-green-blue (RGB) LED and variable resistors. LEDs shine or fade depending on the amount of voltage going through them so by attaching an easily adjustable variable resistor for each color of the LED we made a circuit that could create any color from the three base colors! Jack asked how we can make the LED blink and for that we need a bit of circuitry that can create a periodic pulse. Such a circuit can be made using a chip called a 555 timer, resistors, and *surprise* a capacitor. We ended class looking at a video explains how the 555 chip can be used to create a periodic signal and we may end up using it next class.