Exercise 6 “Very Simple Switching” introduces manually operated switches. The circuit you will construct can use either a SPDT or DPDT toggle switch. For what its worth, this circuit will require some patience if you have big hands and your toggle switch doesn’t have screw terminals. One of the things you have to get used to fairly quickly working in electronics is tight spaces, and very small components which can sometime find themselves on a crowded board. So bring lots of patience.
That said, one of the man take-aways is developing a cursory understanding of how switches work. The text provides a great overview in the section, “Fundamentals: All About Switches“.
Further along in the chapter the author presents schematics and a few symbols. Schematics in my limited opinion is the linqua franca of circuits – no different in importance as hieroglyphs are to Egyptian culture. Learning how to read schematics will definitely open the world of electronics to you in a much deeper and rewarding way. More importantly, the further you venture into this hobby, learning how to read schematics is not an option, its a requirement.
Exercise 7 “Investigating a Relay” introduces the reader to the function of a relay. You’ll learn about it’s remote-controlled ability when it comes to receiving a signal sent by a circuit.
This however is another circuit that may present a few challenges for those with big hands. However, my hands are pretty big and it simply just requires focus and patience.
Once you connect power to this circuit you’ll notice the clicking of the relay right a away. Using the SPST toggle switch will initiate the remote-controlled action. Holding your DMM probes to the leads of the relay while in continuity mode will produce a tone. The tone is an indication of a complete path that allows current to flow. The clicking of the SPST causes the tone to stop, thus the flow of the current is blocked.
In the spirit of full disclosure. I sacrificed a relay to science when performing this exercise in the first edition. For some reason I kept that relay. So I didn’t perform that part of the exercise this time around. However, I would advise that anytime you get the opportunity to see how something works on the inside – go for it.
Exercise 8 “Relay Oscillator“. As a beginner you are probably smiling a little bit at this point because you finally get to used breadboards.
This circuit visually demonstrates oscillation via the use of two LEDS. From my experience, LEDS are kinda like break points when debugging code depending on how they are used. Anyway. The schematics used in the book are super-user friendly. That said, this is probably something I would not get try and get used to. I actually applaud the author for making the schematics in this fashion as it definitely helps the beginner to focus on the task at hand without the complexities of a real schematic. Honestly, there isn’t that much difference but eventually you are going have to learn how read traditional schematics if you want to go further in electronics.
Note: Batteries are expensive. I’d highly recommend buying a power supply if you are serious about this hobby. It is definitely worth the money. I’m not advocating any particular brand but this what I use.
Exercise 6 materials:
Hook up wire
Alligator clip leads
Exercise 7 materials:
DPDT 9VDC relays(2)
Alligator clip leads
Exercise 8 materials:
DPDT 9VDC relay
470 ohm resistor
1000 uf Capacitor
hook up wire