Snap Circuits for E&M Labs #edtech #physicsed

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.

Snap Circuit SC-750R
Snap Circuit SC-750R

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.

SC-750R Manuals
SC-750R Manuals

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.

9 Replies to “Snap Circuits for E&M Labs #edtech #physicsed”

  1. Hi Dan, thanks for the thoughtful review. I often do workshops in public schools so I’m always interested in new tools. I’m always a bit reticent about these kinds of kits, because they lower the kinesthetic experience (holding the components in your hands, bending the leads, wiggling them to get good connections, etc). I know what you mean about the difficulty with breadboards. My solution to this in intro classes is to use small (200 ties?) cheap breadboards. They typically have a paper backing that can be peeled completely off. That leaves the copper inserts exposed, which can then be pulled out and put back in. That helps students see “inside” the breadboard and understand the conenctions (especially if you start by connecting components to a loose insert).

    As for students’ difficulty in following the connections of parallel circuits, I feel your pain. At the same time, I find that a major source of misconceptions is the students’ view of electrons as having some inherent desire to travel from sources on the left to loads on the right (or from up to down, or from down to up, or etc.). Mine are also often tempted to see electrons as wanting to take the first “turn-off”, as if the order of parallel circuit changes the current draw… or think of the current as “starting” from some particular point, rather than starting simultaneously all over the circuit. The tool I use to address these things is to teach them to see “nets” (webs of connected wires), before going into detail about current paths. The confusion they encounter when their wire layout does *not* match their schematic is exactly the experience that helps them confront their misconceptions. So I wonder if these kinds of kits (I’ve used similar products from LabVolt) allow misconceptions to go unnoticed.

    I’d be curious to know, after you evaluate these products, how your students would interpret an actual circuit board (or house wiring circuit, or car headlight circuit) and how much of their conceptual understanding they would be able to transfer. Obviously this assessment shows my bias… it may not bear on your goals at all, but might be food for thought anyway. In any case, I’ll be curious to know what you find out. Keep us posted!

  2. Thanks for the comments Mylene — I especially appreciate the transfer task for kids of applying it to real-life circuits. We often follow the unit up by having kids try to draw a circuit schematic based on the performance of light bulbs in a “mystery circuit,” but I’m thinking our E&M unit exam coming up early next week may just include a house wiring circuit, a voltage divider, or something to push them to a better theoretical AND practical understanding.

    One of my favorite activities to help with misconceptions is the building of 3-D circuit models… I believe there was an article about it a year or two ago in The Physics Teacher, but what I have them do is lay out their circuit schematic on paper, then use pipe cleaners to build a 3-D model above the circuit, with each centimeter of altitude corresponding to volts of electrical potential. Once they’ve built their models for both series and parallel circuits, we go back to the ever-popular “water flowing downhill” analogy, and re-orient the circuits in various directions, as well as following the path of electrons, and showing how electrons flow “uphill,” as opposed to conventional current flowing downhill. Half the kids hate it, half say it’s the best thing we do the entire unit.

    It’s definitely a challenge — hands-on activities to help a wide range of introductory students understand basic electrical circuits needs to be balanced between practical application and tie-in to the schematics against the frustration when students get to the point where they say it’s too confusing, give up, and turn off.

    In all honesty, I’d love to be able to do both, perhaps starting with a kit or cheap breadboards to help them nail down the conceptual aspects, then pushing them to the discrete components and eventually more complex practical circuits! Of course, time and funding are always a factor, which is why it’s always nice to know what tools are available.

    Thanks for the great feedback…

    Best Wishes,

  3. Pingback: Snap Circuits for E&M Labs #edtech #physicsed | Physics In Flux | Educational Electronic Toys

  4. Thanks for the review! I was also thinking about using them for circuit labs — no wires, easy to set up. take down, and store, etc. It’s good to know that the kits are quite there yet for typical guided inquiry labs.

  5. On the bright side, working with the IEEE and RIT Outreach groups, they are quickly feeding this information back to the manufacturer, in the hope that the manufacturer will consider an “educational version.”

  6. I’ve been using the Snap Circuits for basic labs for a few years and I find that they are quite helpful for getting kids in a very simple way to understand the paths that electrons choose. I like them also because they have more elements than just resistors. When I’ve done breadboard labs in the past with just resistors, I don’t know that kids really get what is happening. When they see a fan spin slower they tend to get it more.

    Plus, sometimes, just using the breadboards ads more complication than is necessary to get students to understand the concepts of voltage, current, and resistance. I do agree that it would be nice if you could get more of the same resistor in a kit, but we have 15 of the kits and we just group the resistors together as needed.

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