One of my frustrations in teaching introductory electricity and magnetism to high school students involves discrete component labs. Ohm’s Law is fairly straightforward – a voltage source, a couple wires, and a voltmeter and ammeter will do the job nicely. Series circuits take a bit more time, adding a few more resistors and connecting wires, and now the students have to move their voltmeter around. By the time we get to parallel circuits, however, students have trouble translating the circuit diagram on the page to the mess of wires they see in their lab stations. Then, throw in a moving voltmeter and ammeter, and the educational value starts to decline as the frustration level rises.
One potential solution is the use of breadboards to better organize student circuits. I’ve had some success moving from stray wires to breadboards, but especially in the more general-level physics courses, I spend more time trying to explain the connections in the breadboard and why it works, and students never make the connection to their circuit schematics because they can’t see inside the breadboard.
Recently, with the assistance of the IEEE Electron Device Society and RIT’s Microelectronic Outreach Program, I was able to play with an Elenco Snap Circuit SC-750 Student Training Program kit for two weeks. These kits feature a variety of discrete components placed into snap-on components which make it easy to visualize and observe circuit schematics on the actual circuits being built. The kit includes resistors, transistors, Ics, switches, motors, capacitors, relays, transformers, 7-segment display, diodes, etc.
At first glance, I was impressed with the kit case and foam inserts for storing parts – not only does this keep the kit neat and organized, in a lab situation where I have 120 students playing with the kits throughout the day, it makes it very easy to verify that all components have been put away and stored properly, almost “resetting” the kit for the next group. The kit also comes with five project books, a teacher guide, and three student guides.
The project books themselves are straightforward, showing the final completed circuit put together on a snap-in structural foundation. For educational purposes, though, I would have liked to have seen an actual circuit schematic, and perhaps a few words explaining why each circuit works as it does. It’s great as an electronics toy, but building and documenting laboratory learning experiences would be a fun project for a single or small group of educators.
Components-wise, there were many more components in the kit than I would require, even for my AP-C Physics classes. The integrated circuits, though fun for projects, are not described in detail, and function almost like a magic “black box” in the kits. An analog meter is included, but scale ranges and functions are not described. From a resistor standpoint, the kit has a few resistors of fairly wide-ranges, whereas basic series and parallel circuit labs would probably benefit from 3-4 resistors in each order of magnitude to allow students to easily verify Kirchhoff’s Current Law and Kirchhoff’s Voltage Law for whatever configuration they are placed in. The solar cells are a nice touch, but the equipment for turning a PC into an oscilloscope is a bit much for our high school physics classes, although perhaps beneficial to other groups.
Another terrific improvement opportunity would be the inclusion of a wound hollow solenoid. Throw in a neodymium magnet and the kit could be easily extended for a variety of electromagnetic induction experiments. Throw in two solenoids (concentric?) and some iron cores and you can also explore transformers in a bit more detail. The meter included is a bit lacking, so inclusion of a cheap multimeter and a few more snap-in flexible wires would be of tremendous benefit. Finally, although the kit does include an “open” component in which you can snap in discrete components, having a few more of those could prove useful for extending projects.
In short, I see the Elenco Snap Circuits as a terrific start toward an “E&M Lab in a Kit” offering. The kits are designed and marketed as electronic toys, and function very well in that capacity. My students had a great time playing with the kit and building various projects, but all stated that the educational value could be greatly enhanced with true schematics and descriptions of the “What” and “Why” of the projects.
Our demonstration / trial is being continued in other classrooms at a variety of grade levels, and will be fed back to Elenco as an opportunity to expand their market from electronic toys into educational tools. I would like to thank the IEEE, RIT Microelectronic Outreach, and Elenco Electronics Inc. for the opportunity to be a part of this program.