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.
(The picture for this one looks pretty much the same as the previous one, so I left it out.)
One light is always on.
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.
- 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.]