What does this do?

I felt it was time to take the Electronics class up a notch. I do an assessment. Well, an assessment is not a test, of course you try telling that to children who have heard all the keywords in the world :).

We have been using a two pole two throw switch as a one pole two throw switch (actually as just an on off switch). I thought it was time to introduce the kids to the true power of the switch, series, parallel circuits and also throw in some real life circuit that most people have seen, but don't know how it works.

Thanks to having installed xfig, I get good looking pictures and I can crunch up three in one sheet and the entire assessment can take just three sheets. I split the 16 kids in pairs of two which allows them someone to discuss and debate with, but does not turn into a brawl. The rules of the game are - you can talk to your partner all you want, you collaborate, but you do not cheat i.e. you can get ideas from each other, but you can't just copy what your partner does.

After giving the assessment due respect with a few groans, we get cooking. In a couple of minutes some have oversimplified the problems, but most are in serious discussion. A few o the kids are a little faster and write reasonably long stories to explain what the circuit does. I ask them to keep it brief, but accurate. We come up with conventions LEDs get labels L1, L2 to differentiate them. The switch positions get labels A, B. The answers now look as simple as

SW in A: L1, L2 glows.

SW in B: L1 glows

Nice, we are actually mathematizing the problem.

In time the kids finish 2-3 problems, now, they want to know if their answers are right. I must admit I gave into the temptation and asked some of them to think some more (which of course meant it was incorrect), then I got smart. I told them they could build it and find out. Great, mad rush to get their breadboards (which is nice for an Electronics teacher), except, new rule, you can use the breadboard once you have solved all the questions to check your answer. I am quite impressed that the kids did not take a short cut and continue to work seriously.

It helps me figure out what each child is missing, I fill in some gaps by questioning some of their assumptions. The kids push to figure out if they are doing right I push back with poker face (memo to me: poker face needs more work).

Four groups finish and put the circuits together. The two throw switch gives them some trouble, but they put some of the circuits together and confirm their answer. But, doubt still creeps up and they need an affirmation from me to see if its 'right'. At this point my friend and fellow teacher Ramjee walks in (he is setting up a general workshop for kids to take things apart and put something else together :)). Ah, new meat. The kid tries his hand with Ramjee, 'is what I did right?'. Ramjee asks him to explain how he arrived at the answer and put the circuit together. The shocked kid mumbles something to the effect of not knowing which one of us is worse and decides to take his chances with me.

From having only drawn one circuit before and being all confused about nodes (where you measure independent voltages) before the class to having drawn 6 figures (or more), figured out how to label nodes and name components, to making sense of how the circuit would work...my work was done.