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February 25, 2007

LC V : Building boards and getting to know the boys better

We got down to business of soldering circuits together. To do something different we decided to build lights for the 24 V DC that comes out of the battery of the solar panels. One of the practical difficulties was with leaving the inverter fully powered on since all the rooms were built with a thatch roof and they are always careful about fires. One thing they were careful was to turn off the inverter when power was not required. This, however, meant that when the children come back after dinner there would be no lights till they got into the rooms and turned on the inverters. This was meant to be a low power light that would fulfill this purpose.

This involved pretty much the same current limiting circuit as the torch, but had 7 LEDs. I gave some basic guidelines, but let them arrange the LEDs in fashion that they liked. I also reminded them that they should test all components and in case of LEDs mark the positive ends with the blue marker.

I let them know that for a circuit everyone has the same components, but how you arrange it and solder it shows a bit about yourself and speaks of your work. That they might not think through some aspects of placement that they will learn with this exercise.

With the two soldering irons Balu and Senthil started their circuits. Senthil is an extremely smart guy. Unfortunately, he knows it and that makes him quite cocky. Following which he didn’t test his LEDs and tested only one of his transistors and decided he didn’t need to mark his LEDs either. Balu on the other hand followed the directions. In the mean time one of the students who had been sick for a few weeks came and I asked Perumal to explain how to test different components and build the circuits.
Senthil soon finished, but there were a few bugs in his circuit that I could see visually and he decided to work on it in the next class. Perumal, the dedicated student that he is, took his time with the placement and his circuit worked on the first attempt. Balu also finished his circuit and although I could find no obvious mistakes, his circuit also didn’t quite work. He was really disappointed I had really hoped that his circuit will work given the care he took to build it and it would have given him a lot of confidence. In the evening Krishna also wanted to build the circuit himself and was also able to get it to work on first attempt.

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