Variable Speed Fan With Snap Circuits, Kano Computer

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Pi Day 2016 Project

For Pi Day 2016, I’ll demonstrate how to flash a Snap Circuits LED with the Kano Computer (my...

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In the comments section of my previous article I demonstrated an optical Theremin. This article is the build for that circuit. The circuit and circuits that are similar to it in function have also been called a “Light Sensitive Tone Generator,” “Photo Theremin,” and “Audible Light Meter.” These three circuits are usually based on the two-transistor Light Sensitive Tone Generator from The Forrest Mims Circuit Scrapbook, Volume 1 (Radio Shack, 1976). The circuit built in this article is based instead on the 555 timer IC.
littleBits are color coded electronic modules that connect together magnetically to create simple electronic circuits. They are designed for ages 8 and up so hobbyists, designers, makers, and artists, and can add light, sound, and motion to their crafts and projects. Since they connect up magnetically (no need for circuit boards, breadboards, or solder), you can’t accidentally connect them the wrong way. With littleBits you can quickly build electronic circuits in a matter of minutes.

The color coded modules are divided into four categories. Blue, for power, currently includes three modules—the power module to which you connect the 9 volt battery, a coin battery module, and a USB power module.

As I mentioned in my review of the Chem C3000, it’s sad that science kits usually can’t compete with more mainstream stuff like Guitar Hero. They also tend to be pricey, but the upside is that online and brick-and-mortar stores will carry chemistry sets, microscopes, etc. and since these things usually don’t sell well for the Christmas season, you can often find them after Christmas at a significantly reduced cost.

As you already know, I posted a review of the Thames&Kosmos Chem C3000 chemistry set here.

You can perform simple qualitative analysis to detect certain metals in various substances using borax bead, and flame tests. The inoculating loop for these tests is very easy to make. You can use 20 gauge to 26 gauge Nichrome or platinum wire depending on what is easiest for you to find. To make the loop use a 20cm length of wire and something cylindrical to wrap the wire around such as a small brad or finishing nail. I used an ink cartridge from a disposable ball point pen.

Note: the wire in this photo is oversized to make it easier to see in the photograph.

Wrap the wire around the cylinder to form a loop:

Kudos to Thames and Kosmos for getting their chemistry sets on the shelves at Barnes and Noble. They have these three introductory sets in the store: the “Dangerous Book for Boys Classic Chemistry Science Kit,” “The Chem C500,” and “The Chem c1000.” Sadly, the chemistry set has to compete with the Xbox One and the Play Station 4 so, if there’s any money left over for after Christmas sales you’ll at least have the opportunity to browse the three sets in the store—pick up the box, feel its weight, read the back of the box for the contents and information about the experiments that can be done with these kits. You’ll have time to use your Google-fu to look up reviews for the kits.
In a previous article I demonstrated how to build a conductivity tester out of Snap Circuits for your Science Play and Research kit.

You can use the same circuit with a small modification to build a simple magnetic stirrer. You can also further modify the circuit to make a reversible motor driver. Reversible motor drivers are often used in robotics to drive the robot forward or reverse, turn it right or left, to raise or lower a robotic arm, to open and close a robotic gripper, and so on.