My pesky teaching job kept me from getting back to my new hobby for a while. When I finally did open up my storage box and started fiddling around, I realized I could build the relay from the last activity (Experiment 8) but I didn't really understand what I was doing. I followed the diagram and it worked, but when I tried to explain it out loud to my dog, we both soon realized I didn't really get it.
I'm a visual thinker. I doodle during meetings. I doodle when I make lessons. My principal picked up some of my plans for teaching last week and just shook her head. It was a page of quickly sketched out web pages that I wanted to talk about with my kids. Very few words....just lots of badly drawn images.
When I realized my lack of understanding regarding what I was doing, I grabbed a pencil and paper and started drawing out the circuits. I broke up the entire circuit into it's separate parts. Once I sketched it out, then I built it on the breadboard.
This first circuit just turns on the magnetic switch inside the relay.
I built it on the breadboard and when I pushed the button, I could hear it click as the switch engaged.
So far so good. I understand this!
In the second circuit, I added an LED to the closed portion of the relay switch. It should be lit, until I break the circuit by pushing the button.
It also worked.
For the third circuit, I wanted it to do just the opposite. I wanted the light to be off until I pushed the button.
(The picture for this one looks pretty much the same as the previous one, so I left it out.)
For the fourth circuit, I added both LED lights. Now when you push the button, one light goes out while the other is on.
One light is always on.
It also worked.
This takes me up through experiment 7 in the book. The next one had to do with creating a circuit that automatically opens and closes. I'll show the same step by step process I went through to understand that circuit too....along with some more snazzy pencil sketches!
I found drawing out the circuits really helped me to understand what was going on. It also helped to cement the different symbols into my memory. By the time I hit the fourth sketch, I was drawing the components without looking at the book.
Previous Posts:
- Make Electronics (1)
- Make Electronics (2)
- Make Electronics (3) Radio Shack
- Make Electronics (4) The Toolbox
- Make Electronics (5) My First Experiments
- Make Electronics (6) More parts...More Money
- Make Electronics (7) Soldering
- Make Electronics (8) Relays
- Make Electronics (9) Sketching to Understand
[All images taken by Al Gunn: Creative Commons Attribution 3.0 United States License.]
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