This summer my Grandson Ivan has been coming to spend the day with me twice a week. Ivan is a very serious 10 year old with an interest in electronics. I always try to have a plan in place with experiments and activities. These have gone well with Ivan maintaining focus and interest for sometimes a couple hours at a time. Most of the time it's grandpa that needs a break and not Ivan.

 

Today the topic for our day was learning to use the computer to draw schematics. We began with a simple device, an LED Flashlight. I asked Ivan to tell me the separate components that go into making a flashlight. He told me : Battery, switch, LED, and resistor. I put these names on a piece of paper and then we brought up the schematic drawing program that I like to use. I explained that schematics have a general protocol where higher positive voltages begin at the top and the ground or negative is at the bottom. Also the power supply and input begin on the left side and progress to output of the circuit on the right. After showing him the basics of how the program worked I set him to work drawing the schematic and turned my attention to something else.

 

To my surprise a little later he told me he was done and he had produced a workable schematic of a flashlight. We then took the schematic and I asked him to breadboard the circuit. He has done this before so it was not too difficult a task. Next I told him that the circuit was no longer a flashlight but a room light and we needed to install a three way switch set up. I asked him to revise the schematic and then breadboard the revision. This too he was able to do. By now grandpa was smiling ear to ear as this was showing me that he had really learned and remembered many of the things we had talked about and experimented with in our previous meetings.

 

I proposed that we do something harder so I drew a very crude picture of a latching light activated alarm circuit. I did not draw the symbols but wrote words and made a rough rendition of the wiring. I set him to work producing the schematic and turned my attention elsewhere. Here is the schematic that Ivan drew. Keep in mind that this is only the second schematic he has ever drawn.

 

Ivan's Scematic2.bmp

I now had him breadboard the circuit. He needed a little help in the form of hints to watch polarities and prods to check for all the connections to some of the nodes. Here is the breadboard that he produced. All the placement and wiring logic are his own.

 

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The pin out on the momentary switch was confusing at first but once the architecture was explained he went ahead and used both sides of the poles. As you can see between the anode of the SCR and the LED he did a little creative wandering but the circuit worked and we were both pretty happy. Here is Ivan after completing and testing the light sensor.

 

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Over the years I have been proven to be a very poor teacher. I have lacked the patience. The ability to captivate the interest of my children and grandchildren has always escaped me. After 20 minutes their little eyes are usually glassed over and the visions of toys, video games, or anything else besides what grandpa is talking about floating over their heads. This is why today was a great day. I could see progress and success in what Ivan was able to accomplish today and it felt really good to share this with him.

 

John