I have had an interest in electronics since I got these monthly Science in a Box kits I ordered via an ad I saw in Boy's Life magazine when I was 10. They were all about science so they went from a model of the lunar lander, to fossils to even a number of experiments with electricity and electronics. I remember playing with diode and triode TUBES, building a calculator out of nichrome wire and even learning "Better Be Right Or Your Great Big Venture Goes West." The little pamphlets were incredibly simplistic, while the other books I found on electronics seemed to require that I understand calculus. I wasn't even out of grade school, so my quest to understand electronics was soon eclipsed by working at a garage and learning how to Scuba. C'est la vie! I never lost the interest. I remember in High School spending hours trying to create an electronic dash for my Cortina. I had built a crude digital speedometer and tachometer, and was in the process of replacing the toggle switches with momentary switches and transistors. Then I hit a rather large puddle. The tach still worked, but the speedo was gone as most everything else electronic. The end of high school loomed and I was too busy with other projects, so the old switches and speedo went back in and my future car became vanilla once more.
So, this year I have taken it upon myself to go back and learn some electronics. My goal is two fold: I want to be able to repair circuits, hopefully in the field. I also want to be able to understand what the individual circuits are doing and have a better understanding of the black boxes we rely on to execute our dives. To that end, I decided that a refresher epectronics course that would take me into the understanding of op-amps and other ICs would be a good start. Since I have been impressed with the Maker movement, I have decided to try out their tome on the subject. I got the book on Kindle for about $14 and I had to either source out the ingredients I would need to cook up their experiments or simply buy their two collections of parts. I bought part one on sale at Radio Shack for about $60 and the other I just picked up for about $100. The first ten experiments were quite easy and got my electronic situational awareness going. I didn't like that they had me using little alligator clips holding the devices together, so I opted to use the breadboard from the very beginning. That was a good call. As a youth, we had these perforated boards that I screwed these copper coated springs onto. The wires were then pushed in between the coils of the spring. I have to say that I much prefer the newer bread boards over those.
My first seemingly insurmountable problem came in exercise 11 where they introduced a PUT (Programmable Unijunction Transistor). I assembled the project with ease plugged in the power supply and nothing. Nothing, nada and squat. Oh, the LED lit right up... but it was supposed to flash. I wasn't sure how fast it was supposed to flash, but it was supposed to flash. I wasn't flashing. I checked the connections. There were there and they were correct. I even traced them with logic probe. Everything was hooked up properly. I checked the resistor values... twice. There was only one capacitor. Perhaps the 2N6027 was defective. I tried all four. I searched on the internet for issues with the book. No one complained about exercise 11 not working as advertised. I was stumped. Then I researched the interwebs for more information on the 2N6027. I found a similar circuit and set out to build it. Damn thing flashed. I then started substituting components from one breadboard to the other. Changing the resistors on the emitter made the unit work. The values for each weren't that far off. Maybe I had a bad resistor, but the logic probe didn't suss that out and it should have. I measured the resistance and lo and behold. I had put in a 470 instead of a 470K resistor. Wow... what a difference a decimal point or three makes.
Since then, I have worked through experiment 14, "A Pulsing Glow". Up to experiment 11, I had not learned much. It's not that the book was poorly written, it's just that I had already learned up to that point. In fact, I give Make: Electronics props for holding my attention during my review. Is it simplistic? It has to be. During the reading, they give ample suggestions for additional reading that will help you understand the theory better. The book serves as a primer and an outline for understanding electronics and nothing more. It's entirely up to the reader to increase their understanding of any particular subject and the interwebs is replete with information on specific subjects. So from here on out, I will be blogging my progress. Don't expect daily updates, though that may happen. My electronics bench is down in the Grotto and I have a number of projects going on down there. In fact, it's time I finished rebuilding the radial arm saw I started back last September. I'm glad I have schematics and diagrams on how it goes together. Life often intervenes into the plans we make. In addition to that, I also need to finish my Sprinter project and I also started building a UV light table for exposing photo-sensitive copper clad boards to turn them into PCBs. The first 200 LEDs and resistors have been soldered in. I am about a third finished in that respect and still have to build an enclosure for it. The radial arm saw would help that process.
So, this year I have taken it upon myself to go back and learn some electronics. My goal is two fold: I want to be able to repair circuits, hopefully in the field. I also want to be able to understand what the individual circuits are doing and have a better understanding of the black boxes we rely on to execute our dives. To that end, I decided that a refresher epectronics course that would take me into the understanding of op-amps and other ICs would be a good start. Since I have been impressed with the Maker movement, I have decided to try out their tome on the subject. I got the book on Kindle for about $14 and I had to either source out the ingredients I would need to cook up their experiments or simply buy their two collections of parts. I bought part one on sale at Radio Shack for about $60 and the other I just picked up for about $100. The first ten experiments were quite easy and got my electronic situational awareness going. I didn't like that they had me using little alligator clips holding the devices together, so I opted to use the breadboard from the very beginning. That was a good call. As a youth, we had these perforated boards that I screwed these copper coated springs onto. The wires were then pushed in between the coils of the spring. I have to say that I much prefer the newer bread boards over those.
My first seemingly insurmountable problem came in exercise 11 where they introduced a PUT (Programmable Unijunction Transistor). I assembled the project with ease plugged in the power supply and nothing. Nothing, nada and squat. Oh, the LED lit right up... but it was supposed to flash. I wasn't sure how fast it was supposed to flash, but it was supposed to flash. I wasn't flashing. I checked the connections. There were there and they were correct. I even traced them with logic probe. Everything was hooked up properly. I checked the resistor values... twice. There was only one capacitor. Perhaps the 2N6027 was defective. I tried all four. I searched on the internet for issues with the book. No one complained about exercise 11 not working as advertised. I was stumped. Then I researched the interwebs for more information on the 2N6027. I found a similar circuit and set out to build it. Damn thing flashed. I then started substituting components from one breadboard to the other. Changing the resistors on the emitter made the unit work. The values for each weren't that far off. Maybe I had a bad resistor, but the logic probe didn't suss that out and it should have. I measured the resistance and lo and behold. I had put in a 470 instead of a 470K resistor. Wow... what a difference a decimal point or three makes.
Since then, I have worked through experiment 14, "A Pulsing Glow". Up to experiment 11, I had not learned much. It's not that the book was poorly written, it's just that I had already learned up to that point. In fact, I give Make: Electronics props for holding my attention during my review. Is it simplistic? It has to be. During the reading, they give ample suggestions for additional reading that will help you understand the theory better. The book serves as a primer and an outline for understanding electronics and nothing more. It's entirely up to the reader to increase their understanding of any particular subject and the interwebs is replete with information on specific subjects. So from here on out, I will be blogging my progress. Don't expect daily updates, though that may happen. My electronics bench is down in the Grotto and I have a number of projects going on down there. In fact, it's time I finished rebuilding the radial arm saw I started back last September. I'm glad I have schematics and diagrams on how it goes together. Life often intervenes into the plans we make. In addition to that, I also need to finish my Sprinter project and I also started building a UV light table for exposing photo-sensitive copper clad boards to turn them into PCBs. The first 200 LEDs and resistors have been soldered in. I am about a third finished in that respect and still have to build an enclosure for it. The radial arm saw would help that process.
