Two of my nine grandkids are crazy about making “computers” from discarded keyboards, wires, cables, and whatever other electronic odds and ends they can find. Here’s an example:
Even though they are just turning six, one of them is certain that he wants to be an Electrical Engineer. They were particularly impressed by a little battery tester I had made to check AA, C and D cells so making one like it became the subject of the first meeting of our “Engineering Club”. My daughter in law, who goes by the pseudonym “Blue Yonder“, thought it would be helpful to share projects like this with others so here we are in “Grandfather’s Workshop”!
The easy part is putting the battery tester together. Finding the parts is a little harder. Here’s the parts list:
1) mounting board – minimum size of 4.5″ x 4.5″ x 1/2″
2) mounting screws – #4 x 1/2″ metal pan head (Home Depot 24741)
3) battery holder – AAA, AA, C or D (AA – Radio Shack 270-401A or see below)
4) knife switch – SPST (single pole, single throw)
5) bulb holder – miniature, screw type
6) bulb – screw type, 1.5 volts
7) wire – no extra wire is required
There are a number of places that have one or more of the electrical items but I found only one place that has them all, Christian Book Distributors. If you find any other sources please let me know.
At these prices, get an extra bulb holder, battery holder and maybe a SPDT switch. We will need them for future experiments. Other sources to check are Arbor Scientific, Science Lab and Hobby Engineering.
It’s not much but they seemed very pleased with the results and we had a lot of fun building it.