Variable Speed Fan With Snap Circuits, Kano Computer

In a previous How-To Guide I demonstrated how to blink a Snap Circuits LED with the Kano Computer...

IUPUI researchers use stem cells to identify cellular processes related to glaucoma

INDIANAPOLIS -- Using stem cells derived from human skin cells, researchers led by Jason Meyer...

Pi Day 2016 Project

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

LIGO, Gravitational Waves, And Laser Interferometry

UPDATE: LIGO has detected gravitational waves. ...

In my previous article DC Versus AC I discussed how a diode can be used as a rectifier to convert alternating current (AC) into direct current (DC) because the diode allows current to flow in one direction, but not the other.

The diode is the simplest semiconductor electronic component, but the physics of how they work is perhaps somewhat complicated. There are many resources available on the web such as the Edison Tech Center semiconductor resource page.

This build is a simplified Leeuwenhoek microscope made from CD-ROM drive parts and construction toys. My initial design was simply a rectangle of corrugated cardboard with a hole punched in it and one of the glass spheres from the Chem C3000 kit, but the magnification was disappointing and the field of view surprisingly narrow. Another method would have been to demonstrate melting a glass rod, drawing it to a thin glass fiber and then heating the fiber into a glass sphere. Though this would have been historically appropriate, it might be difficult to find this type of glass rod and they might be expensive.
I was able to find the EYESPY Spydercam at Goodwill. Several hacks for it came to mind, but the simplest is attaching it to a remote control vehicle. I have an old Lego remote control car that’s been gathering dust so I decided to use it for this article. You can, however, attach it to any remote controlled vehicle you may have. I've attached it to the Popular Mechanics RC Tank--hint: use a rubber band to fasten the Spydercam to the battery block. You might not be able to find the RC Tank any more except on eBay. I've also attached it to the Snap Circuits Rover.
In a previous article I built a magnetic stirrer using littleBits and Erector set parts for the home laboratory. At the end of the article I added a design for a sample rotator (a device used to continuously mix lab samples). I have (somewhat) improved the design of the Erector set and littleBits sample rotator and in this article I document the build.

The Rotator ”Base”

Follow me on Twitter: @SteveSchuler20. Back in the day, some chemistry sets came with a mechanical centrifuge. They were operated similar to those old-timey pump style tin spinning toy tops. This is the style centrifuge that came with my chemistry set:

Note: I came up with this story idea long before I was able to find a second-hand salad spinner and now I can’t remember where I found this picture. I am unable to cite its source.

Here’s another example of a chemistry set centrifuge on Evil Mad Scientist Laboratories’ site:

While writing my series on the Science Play and Research Kit, I hoped to survey chemistry sets that are already on the market. I was able to get a reviewer’s sample of the Chem C3000 and you can take a look at my review of the Thames and Kosmos set here.