#1099 How I learned electronics

Estimated read time: 1:20

Summary

In episode #1099 of "How I learned electronics," presented by IMSAI Guy, the host humorously and candidly shares his self-taught journey into the world of electronics. Despite having a physics degree, he admits that his knowledge in electronics didn't come from formal education but through experimentation and curiosity. Delving into the ARRL handbook and playing with components like op-amps on a breadboard, he emphasizes learning by doing rather than memorizing equations. The video encourages viewers to explore and play with electronics firsthand to develop an intuitive understanding that formal education might not offer.

Highlights

No formal training in electronics, relied on self-teaching. 📚
Curiosity as a kid led to hands-on experimentation. 🧒🔍
Ham radio and ARRL handbook pivotal in learning. 📻📘
Learning emphasized through doing rather than theory. 🤖➕
Don't fear mistakes; they’re part of the learning journey. 🛠️

Key Takeaways

Learning electronics can be self-taught through curiosity and experimentation, not just formal education. 🎓
The ARRL handbook played a crucial role in practical learning about electronics. 📚
Understanding at a gut level is emphasized over rote learning of equations. 🤔
Practical experimentation, like playing with components on a breadboard, is key to learning. 🔌
The journey involves embracing mistakes and learning from hands-on experiences. 🔄

Overview

IMSAI Guy kicks off the video discussing how he learned electronics without formal training, attributing his knowledge to a self-taught approach fueled by curiosity. He humorously notes that while his physics degree involved complex equations, these didn’t aid in understanding practical electronics like op-amps, underscoring the gap between theoretical and practical knowledge.

The cornerstone of his electronics education was the ARRL handbook, which offered practical insights and experiments over academic equations. Through trial and error, IMSAI Guy discovered the basics of circuit components such as resistors and op-amps. He relays the importance of getting tangibly involved by using breadboards to build and test circuits, highlighting that making mistakes is a valuable part of the learning process.

IMSAI Guy's candid narration encourages viewers to learn by "doing" rather than waiting to know everything theoretically. His message is clear: dive into electronics with a sense of playfulness and curiosity. He reassures that making errors is okay and proposes that intuition, developed from hands-on experience, is often more beneficial than textbook knowledge, culminating in a message that resonates with DIY enthusiasts everywhere.

Chapters

00:00 - 01:30: Introduction to Learning Electronics The chapter 'Introduction to Learning Electronics' begins with the instructor addressing a common question: How does one learn electronics? The instructor shares their personal journey and method of learning electronics, emphasizing honesty about the process. The approach offered might work for some individuals while acknowledging that different methods may suit different people.
01:30 - 04:00: Self-taught Path and Early Curiosity The chapter titled 'Self-taught Path and Early Curiosity' describes the narrator's journey in electronics despite not having any formal training in the field. The narrator holds a degree in physics, which provided knowledge of fundamental science concepts, but did not specifically cover practical electronics or circuit design, such as working with operational amplifiers (op-amps). The narrator emphasizes the difference between theoretical knowledge, like understanding Maxwell's equations, and practical skills needed for electronics, highlighting a self-taught approach to learning and developing expertise outside formal education.
04:00 - 07:00: The ARRL Handbook and Hands-On Learning Approach The speaker emphasizes the importance of self-learning in their journey with the ARRL Handbook. They highlight that all their knowledge has been acquired through self-teaching by observing others, trying processes themselves, reading extensively, and continually educating themselves. The speaker shares a personal insight, acknowledging a sense of vulnerability but remains committed to honesty in their approach.
07:00 - 10:00: Understanding Simple Electronic Concepts The chapter titled 'Understanding Simple Electronic Concepts' discusses the belief that anyone can teach themselves electronics much like one can learn to cook. The author shares their personal experience of learning electronics driven by curiosity from a young age. This involved experimenting with electronic items, such as fiddling with a radio to alter its sound or disassembling items to understand their internal workings.
10:00 - 15:00: Building and Experimenting with Filters The speaker shares their initial interest in electronics, which began with a curiosity that led them to explore ham radio. Through ham radio, they accumulated significant knowledge about electronics, not directly through the radio or Morse code, but primarily because of a specific book they encountered. The speaker hints at having discussed this book previously.
15:00 - 18:00: Exploring Low Pass Filters The chapter titled 'Exploring Low Pass Filters' begins with an introduction to the ARRL handbook, a valuable resource that is affordable and rich with information. The author intends to demonstrate the process of learning by selecting a topic and explaining their approach to understanding it.
18:00 - 21:00: The Role of Math in Electronics The chapter titled 'The Role of Math in Electronics' explores the various applications of operational amplifiers (op-amps) in electronic circuits. It starts by encouraging the reader to explore various topics of interest in electronics, such as oscillators, before delving into op-amps. The chapter introduces the concept of active filters, explaining their definition and purpose. Active filters are described as simple yet crucial components in electronic circuits, which utilize op-amps to enhance performance. The chapter emphasizes understanding the mathematical principles behind these devices and how they contribute to the functionality and effectiveness of electronic systems. Overall, the chapter aims to provide insights into the critical role that mathematical concepts play in the design and analysis of electronic components and systems.
21:00 - 25:00: The Importance of Experimentation The chapter delves into the role of experimentation in electronics, focusing on signal processing using passive components like resistors, capacitors, and inductors. It discusses the limitations of passive components in preserving signal integrity and highlights the use of operational amplifiers (op-amps) as a solution to maintain signal strength. The narrative underscores that op-amps in this context primarily serve as inverting amplifiers, repeatedly emphasizing their uniform role across different applications within the circuitry.
25:00 - 30:00: Learning Through Doing and Final Thoughts The chapter delves into complex circuit filters, discussing their construction and function. It emphasizes the use of non-inverting amplifiers and buffers as foundational elements within these circuits. The chapter also highlights the role of passive components in enhancing circuit functionality. The speaker suggests analyzing the equations associated with these circuits to gain a deeper understanding of their operation.

#1099 How I learned electronics Transcription

00:00 - 00:30 [Music] all right how do i learn electronics i hear this question all the time how do i learn electronics and i'm going to be very honest today and tell you how i learned electronics and this is dead serious this is how i did it maybe it'll work for you maybe other people are different but this is how i learned electronics i do
00:30 - 01:00 not have a any formal training in electronics at all i never took a double e class i have a science degree i think i mentioned i have a physics degree but that doesn't teach you that doesn't teach you circuits like i could do maxwell's equations but that doesn't do you any good in putting together an op-amp you know what's maxwell's equations have to do with an op-amp it won't do you any good at all and
01:00 - 01:30 what i found was there for me it was all self-taught so everything i know everything i've taught it's all been self-taught see other people do it try it read about it teach yourself and like i say continually teach yourself this is an insight and it feels to me it feels to me it makes me a little vulnerable but i want to be very honest in how i
01:30 - 02:00 believe you can teach yourself electronics it's almost it's not like it like anybody can cook right that kind of thing all right so how how did i learn electronics well it was out of curiosity as a kid i was very very curious about everything and i was very very curious about electronics and anytime i could try it something out i tried something i didn't know what i was doing i fiddled maybe with the radio to make it sound funny or take something apart just to see how it
02:00 - 02:30 was inside right i had a curiosity in electronics and so i got into ham radio and ham radio i think is where i probably learned the most about electronics not because of the radio itself you know morse code's not going to teach you electronics but it's because of this one book all right and i've showed this book before and it is the
02:30 - 03:00 arrl handbook okay and this is a great book it's very inexpensive on the used market and um it has a whole bunch of great stuff in here and so while what i want to do today is just kind of pick something out and kind of i'll show you what i what i did how how i learned okay so let me rearrange things a bit
03:00 - 03:30 all right so just go to a page whatever is interesting you at the time okay so let's say you learned about oscillators but now you want to learn about op amps and you go okay uh i know op amps can do different things and oh here's here's something op-amps do okay and so let's take a look at that all right and these are simple active filters right uh what does it mean to be an active filter well an active filter has
03:30 - 04:00 electronics in it you can make filters out of just passive components just resistors and capacitors and inductors and stuff but a lot of times that throws away signal and you want to keep that signal and so you put some gain in in the in the mix and so you put these op-amps in there and if you take a look at these well the op-amps really aren't doing much they they're just all inverting amplifiers inverting amplifier inverting amplifier inverting amplifier you know that's all these things are doing here and you can look down here you say oh
04:00 - 04:30 here are some even more complicated uh circuits down here all right and these are filters too but they're much more complicated than these what what are they doing well in in all reality though like non-inverting amplifier non-inverting amplifier buffer right there they're very simple things and then they put these passive components to do to do the other things right so um what i would do is i would look at this and i would see these equations now i think one of the
04:30 - 05:00 biggest disservices the educational system does is to emphasize the math too early um eventually maybe you'll need to get there but you know some people will never need to get here um and i believe that the way that it's taught they will throw equations at you and not tell you where the equation came
05:00 - 05:30 from they just say well here's an equation and memorize it and then you learn how to put numbers in the equations and you'll get numbers out the other side of the equation and you'll pass the test and get good grades but you really won't ever understand what's going on and i really believe that for me it was more important to understand everything at a gut level okay and maybe that's why i'm maybe good at
05:30 - 06:00 teaching simplistic ideas maybe i'd be a complete failure teaching tensor calculus right but i understand how to look at something and intuitively kind of figure things out so you know if all you want to do with electronics is maybe fix things you know you'll never design it but you need to know enough to fix it and those are two different things and rarely are there educational systems
06:00 - 06:30 that will teach you the basics of things in a clear way so anyway so so this is how i taught myself right let's take a look at these three things here and um here's an op-amp and it's got some r's and c's and stuff well the first thing i'm going to do is i'm going to make it work i'm going to do okay if if i if i have one word of wisdom on learning it's due don't wait okay you'll be waiting for godot go ask your literary friend what that
06:30 - 07:00 means um so um do so here's an op-amp find an op-amp doesn't matter which one hook it up and put some resistors and capacitors around it don't go to the equations don't go try to figure the math out don't do any of that stuff just put stuff in see what happens right you're not going to break anything and if you do break anything who cares right so this one's got two r's and a c so what values am i going to use well i'm going to use my favorite
07:00 - 07:30 resistors remember i asked the question once before what's your favorite resistor minus 10k i don't know i just like it 10k um and i've got 5000 of these capacitors on a reel and so i'm going to use those because they're my favorite capacitor because i've got 5 000 of them got to do something with them so i'm going to use 10k and .01 microfarads right these are 0.01 microfarads do i know what frequency this is going to do anything at no i have no clue right but let's hook it up
07:30 - 08:00 and let's go see what it does okay and so let's go ahead and hook this one up first right and what does it say it is a uh a it says it's a low pass filter okay all right it's supposed to be a low pass filter i don't know i'm gonna hook it up all right so let's let's hook this up all right so here's my little breadboard you know use these little breadboards they're great and i just put some components in and we'll turn it on um so you may be fortunate that your oscilloscope can do fancy things but if
08:00 - 08:30 it can't do fancy things then then don't be discouraged about that um uh just do it you know a little bit at a time okay so let's uh okay so i'm going to put some signal into the front that'll be our yellow and we'll get some signal out of the back end that'll be our cyan and remember it's an inverting amplifier remember i pointed it out so is it an inverting amplifier well absolutely look it inverts and you might even see a little bit more detail here you can say wait a minute it's not quite
08:30 - 09:00 right okay this isn't quite right people say i should change my scope but so you can take a look at this and you can go okay it's inverting but they don't line up right if it was just 180 degrees out of phase they would line up so there's a phase change here well that's interesting i wonder why there's a phase change right you don't know why it just does it and and maybe that's interesting maybe that's not interesting okay um but it does that so it's something to
09:00 - 09:30 kind of squirrel away why is there a phase change and do i care if i'm just going to send music through it i don't care right it's gonna run a speaker i don't really care about phase and when i started using electronics i never worried about in fact i still don't you know all these years i don't care about face for the kind of stuff i've done i've i've rarely really really ever cared about phase right all right so we're at one kilohertz here and uh we can change that frequency right let's put this back on and run
09:30 - 10:00 um we can change it down to uh let me do what people say i should do menu hold up they say should i should put in some hold off here and that will help my triggering yeah i don't think it's going to i think i just don't think it helps at all there is there is noise reduction i can put in i can put in noise reject that helps a lot the other thing that i've seen that helps is to limit the bandwidth of my scope
10:00 - 10:30 i'm never going to go very fast so i'm going to change my bandwidth here to 20 megahertz right sorry if i'm in the way of the camera here but i'm going to change my bandwidth on these uh traces here to be uh to be 20 to be 20 megahertz okay there we go anyway i'm going to change the frequency i'm going to change it down here to 400 hertz and i'll go higher and higher and higher oh it's getting smaller why is it getting smaller okay it starts out big and then it gets smaller and smaller well
10:30 - 11:00 it's a low pass filter so it means that high frequency stuff is going to be attenuated and sure enough it goes down okay so you know low frequencies big high frequencies small and so oh okay that's what a low-pass filter does right and so you can learn doing it this way you could inject a signal and put it into a speaker you can listen to it do i hear high frequency what when does it
11:00 - 11:30 when do i not hear the frequencies you could do it that way if you have a fancy scope like this it has a bode plots built in i think i showed that before we'll go ahead and run one here all right so that took a couple minutes and uh this is the frequency response of the system uh we have 10 hertz to 100 kilohertz and it goes along just fine then it starts to roll off and that's when it attenuates and so we can use our cursor
11:30 - 12:00 and we can come out here to the 3 db point which is about there and we can say this filter rolls off about 2 kilohertz okay so does that make any sense two kilohertz i don't know i just found some components on the bench and i threw them in there and i made a filter that's a two kilohertz filter good for me um this phase information you know even to this day i don't know what that means i have no clue i really under i i understand it but i
12:00 - 12:30 don't know how to effectively use it okay there are things called polls and zeros and roll-off and in order to make a system stable and all you know if you had a feedback if you really need to be an engineer go to engineering school right um if you just want to putter in your garage and do things and i've designed products that were sold on the on the open market and i don't know what this damn face does right i just don't know and it
12:30 - 13:00 didn't matter to me it just didn't matter um so there's a lot of electronics that you don't need to understand to get by there might become there might be a point in time where you really need to know something right like i was designing an amplifier the other day i think was interested in them i was interested in microphones and all the microphones have jfet transistors in them right and jfet transistors are strange beasts they're very very strange and i thought about doing videos on jfet
13:00 - 13:30 transistors and stuff but i i decided not to for whatever reason but you know i asked my friends who were like died in the wool electrical engineers and uh you know they're a lot more engineering than i am and i asked him well teach me about these these jfed amp you know jfit transistors and they go well i've never really had a chance to use them and they didn't know they didn't know and so a lot of electronics is going to come down to you will learn it when you
13:30 - 14:00 need it okay don't worry about it you will learn it when you need it you need to get some basic things out of the way but a lot of times if you get to a point where you're needing to solve some type of a problem in your design go research it at that point in time it is time to become the expert go read a book go to a website go try to figure it out i need to figure out what filters are oh i start reading about filters oh there's things called bessel filters and butterworth filters and chebyshev filters oh and and then
14:00 - 14:30 you start reading more and more and more about them and you become a filter expert enough enough of an expert in order to get your job done you know and then the next time somebody will ask you you say oh well i think you should put in a sixth order chebyshev and then people will think you're super smart no you're not super smart you just have more knowledge than they do all right so you know there is our um there's our low pass um i was going to do this all on camera but i don't think it really matters
14:30 - 15:00 not for what i want the video to be so i could i could then take that capacitor and all i have to do is move it i just move it from here and i put it in the front and it turns into a high frequency a high pass filter right and then i put in two filters i keep the one i already had and i keep this one too i put them both in there and guess what it magically turns into a bandpass filter it goes up and then it goes down right this one stays high and then it goes low this one goes low and then it goes high this one goes up and then it
15:00 - 15:30 goes down and you see that on the oscilloscope you played with it or you hear it like you could use this to like emphasize a particular frequency of sound that you want you know if it's a spoken voice maybe you make a a peak you know at 3 000 hertz or something maybe at 2000 it's even better right be better for your voice anyway you play with it you try it you do it do um anyway that's kind of the point of the video just go do um and then
15:30 - 16:00 we'll end it with going the next step okay so step one get a gut feel for it here are some circuits that do filtering okay enough put those in my brain if i see those things i'm kind of familiar with them why do they work well there's a capacitor and only high goes through a capacitor dc won't go through the capacitor but ac will go through the capacitor high frequency will go through so that's the high pass filter right whenever you put a high pass and a feedback it does the exact opposite it becomes a low pass and then
16:00 - 16:30 if you put them together um if you have a high pass and a low pass both together hey guess what you're going to end up with a band pass right and so that's just the gut feel that's what you need to get out of this thing so what is the step what is the second step the second step is um okay math it is important to learn the math but don't learn it first learn it like second or third right you know safety third like math third and keep the math down to a minimum right it says um okay it says gain it gives us an
16:30 - 17:00 equation for gain and that is equal to minus r1 divided by r2 why is there a negative sign because it's an inverting amplifier and then r1 over r2 well that's just the regular uh you know amplifier part of this thing forget the capacitor it's just r1 over r2 it's the same this has always been the capacitor doesn't have anything to do with any of that in there right that's that's the gain of the system and then it has a cutoff frequency so
17:00 - 17:30 frequency like cut off and it says that is equal to 1 over 2 pi r 1 c and you're going to go ah math that's okay if you're afraid of math that's fine and a lot of times you don't need to know the math but if you want to get in easy okay do simple do little simple things like this first don't go into all the crazy math right away just do simple things okay so what do we have here well we have two pi okay we know what that is r it's my
17:30 - 18:00 10k it's my favorite resistor 10k and what is it what's c it's my favorite capacitor zero one microfarads okay and i just need to punch this into a calculator um so let's do that um we have two we have pi we have 10 000 and we have 0.01 micros and we have one over that and it says
18:00 - 18:30 1.6 kilohertz okay as e to the three so that's k so one points 1.6 kilohertz what did we measure two does that mean we're doing something wrong no we're not doing anything wrong okay capacitors have a tolerance they're not going to be exactly 0.01 resistors have a tolerance they're not going to be exact okay you spent you spent 20 cents on your circuit
18:30 - 19:00 is it going to be any good it's going to be okay and then you measured it maybe in a crude way right is 1.6 about the same as two yeah they're the same okay so don't get stuck up on making everything super accurate and if you had this in an audio circuit would you hear the difference between a two kilohertz roll-off filter and a 1.6 kilohertz roll-off filter no nobody's gonna hear that um so um anyway yeah well i don't know if that helped um
19:00 - 19:30 video didn't really turn out the way that i really want it to you know it's i had these visions of imparting certain knowledge and sometimes it's just very very difficult to get it across um but uh anyway i hope to help helped a little bit you know just find things and hook them up and just play with them you know don't worry don't worry about the theory just try things out and you know put put an extra thing in right well what if i
19:30 - 20:00 do this what does that do right um you don't need to stick to the script but like i said most important thing is go do you