Ask HN: How to self-learn electronics?
The Context<p>Electronics is a complex topic but doable with the right strategy.  Suppose instead of electronics I wanted to learn &quot;how does my mind move my finger?&quot;.  As a person with a mind and a finger the answer is quite simple: my mind creates the command and the finger moves.  While this is true, under the covers though the actual details are a lot more complex.  The good news is that electronics is a lot simpler than moving your finger.  The trick is to learn the simpler ideas that allow you do actual things without getting lost in the details.<p>Another problem is that once someone understands an area of learning they tend to want to teach it from a top down perspective.  In the case of electronics it&#x27;s &quot;well here&#x27;s Maxwell&#x27;s equations and it&#x27;s all you really need&quot;.  But people tend to learn better working from the bottom up.  Understanding various simple things and building up the abstract structure as they go.<p>So here&#x27;s my recommendation for a hierarchy of learning for electronics.  Understand that at each step you&#x27;re never getting &quot;the complete truth&quot; but also you&#x27;re not getting actual lies.<p>First electronics is divided into to types of things. Passive components and active components.  A resistor is a type of passive component and a transistor is a type of active component.<p>It&#x27;s best to get solid foundation in passive components before moving on to active components even though &quot;proper electronics&quot; is about active components.  That&#x27;s because most of the time active components are actually thought of as a kind of combination of passive components.<p>So start with a battery and a resistor and the equation V=IR.  While this seems way too simple it&#x27;s actually the idea that used in a lot of electronics so it&#x27;s good to understand it pretty well.  And it&#x27;s conceptually pretty clear.<p>Once you feel you have a good solid, unshakeable under standing of one resistor and a voltage supply move on to two resistors in series and then two resistors in parallel.  Calculate the voltage and current for each one.<p>Next keep adding resistors in arbitrary combinations up to say a dozen resistors and become confident that you can calculate the voltage and current regardless of any combination that is given to you.<p>At this point it&#x27;s very helpful to think of current in terms of water flow and voltage in terms of water pressure.  (The resistor is analogous to the size of the pipe that the water is flowing through) This analogy, with some refinements, goes a long way in electronics so it&#x27;s good to start thinking like this.<p>The next step is to take a look at a circuit of a resistor and a capacitor in series. This is the classic RC circuit that is used a lot. A capacitor can store energy and so its characteristics can be quite different than those of resistors.  However, with a little mathematical sleight of hand capacitors can be treated &quot;just as if they were resistors&quot; in many circumstances and this makes calculations (and thought processes) quite a lot easier.<p>Learn the mathematical techniques of analyzing circuits made of resistors and capacitors driven by both an AC voltage and a DC voltage for some very simple circuits.  One resistor and one capacitor is plenty for starting.<p>Note that these circuits have both a &#x27;transient phase&#x27; and a &#x27;steady state&#x27; phase.  You can think of this in terms of picking a ball up from the floor and then dropping it.  The time during which the ball is bouncing is the &#x27;transient&#x27; stage and after the ball stops bouncing that&#x27;s the &#x27;steady state&#x27; phase.  For the most part electronics concerns itself with the &#x27;steady state&#x27; phase.  However, a circuit driven by a steady AC (sinusoidal) voltage (or current) and be analyzed in a steady state manner even though the values are varying with time.<p>The other standard passive component is the inductor.  Don&#x27;t worry about it until you get quite confident in your understanding of capacitors since inductors are intuitively harder to figure out and mathematically both components are treated very similarly.<p>Active Components
While there are quite a few &#x27;semiconductor&#x27; based active components simplify by studying the three main types first.  These are diodes, bipolar transistors(npn, pnp) and field effect transistors (FET&#x27;s).  The theory of how these devices actually work is very complicated and not really worth effort.  The diodes are quite simple to understand so start with those.<p>The transistors are trickier.  They operate in two modes, non-liner and linear.  Non-linear is messy and best left to later.  The linear regime is where these are mostly used and is conceptually not too difficult.  In fact they operate in a manner not much different than the knob that controls water flow (there&#x27;s that metaphor again) in your shower.  A transistor had three terminals one of the terminals is used to change the resistance value between the other two terminals.<p>In the case of bipolar transistors the controlling input is a current.  With FET transistors the controlling input is a voltage.<p>And that&#x27;s it really.  There are more complicated things like phase locked loops and more niche type devices like SCR&#x27;s but these are the basics.<p>Once you start to actually put circuits together do yourself the favor of learning to solder and wirewrap rather than using bread boards.  For a tiny bit of extra effort you&#x27;ll likely save yourself hours of frustration because your circuit connections will be much more reliable.