really basic theory doco

[John Frum]

Is there a resource on this site to describe the really basic stuff.
It seems to me that core of the onion is the understanding of the primitives which are

• voltage
• resistance
• current

Those are the primitives at the center of the onion.

A better understand comes from understanding how these primitives relate to one another.
That is the next layer of the onion.

Do you agree or disagree?
Different field but related idea, how do you feel about ham license requiring the morse code?

 

[45North]

There are yt videos on the basics of electricity, including some by will.

 

[time2roll]

google ohm's law

 

[svetz]

There's a wiki page on ohm's law. But it's a catch-22, that is why would anyone visit it if they knew what it was or know to visit they didn't?

The very first entry in the FAQ index is the "beginner's video playlist", and the first entry there is electricity explained.

Different field but related idea, how do you feel about ham license requiring the morse code?

Ambivalent. It's like teaching someone binary for coding; it may or may not be useful. How many ham's actually use morse code every day?

 

[John Frum]

Ambivalent. It's like teaching someone binary for coding; it may or may not be useful. How many ham's actually use morse code every day?

Its my opinion that the mathematical representation of logic should not be abstracted away, even if it could be.

 

[MrM1]

I do not understand the onion at all ... but this is my favorite Ohm's Law pic. I like the characters ?

 

[Dzl]

Is there a resource on this site to describe the really basic stuff.
It seems to me that core of the onion is the understanding of the primitives which are

• voltage
• resistance
• current

Those are the primitives at the center of the onion.

A better understand comes from understanding how these primitives relate to one another.
That is the next layer of the onion.

Do you agree or disagree?

1000% agree, not understanding these fundamentals really held me back for a long time. I preach this often in responses to basic questions that seem to lack clear understanding of the fundamentals, but most folks seem to just want quick answers to practical questions, not a homework assignment.. Still I think its really important to just get a basic conceptual grasp of the fundamentals (at least 5 basic units--Voltage, Current, Resistance, Watts, Amp-hours and/or Watt-hours--and how they relate to one another). And even if the majority are not interested in spending the time to understand the foundational concepts, I think that there are enough people who do want to, but either don't know where to start, or are too overwhelmed by it all (like I was not so long ago), that it would be worthwhile.

The video that helped everything 'click' in my mind was "Introduction to Simple Electrical Circuits" by Solid State Workshop on youtube. RSD academy also has a great series on basic concepts. Its a great mildly-technical conceptual overview, that allowed me to understand a lot of things intuitively that had seemed very intuitive before that. I knew the basic math and formulas, but it was this video that allowed me to actually 'get it.' I always recommend it to less technically/mathematically inclined folks.

For not super mathematical folks like myself, explaining/understanding 'the nature' of the units is as important as understanding the formulas. Grasping voltage was the puzzle piece that really helped everything to click. My understanding is still quite limited and basic, but understanding that voltage can be roughly thought of as "electrical pressure" or "a pushing force" and that it is an "across variable" that measures the difference between two points in a circuit, really helped me and allowed me to start answering/understanding some of my own questions.

 

[Dzl]

I do not understand the onion at all ... but this is my favorite Ohm's Law pic. I like the characters ?

View attachment 43695

That is a good one, I have the circle and the cartoon saved separately on my computer, but hadn't come across a picture that fits it all in one, this is great!

 

[Johncfii]

A better understand comes from understanding how these primitives relate to one another.
That is the next layer of the onion.

Of course, understanding how they inter-relate is very useful. Ohm’s Law, which goes back to the early 1800’s, is the algebraic expression that exactly describes how voltage, current, and resistance relate to each other.

Different field but related idea, how do you feel about ham license requiring the morse code?

Don’t know how that question relates, but our culture, and lists of important job skills, changes with technology.

Just as Express Mail delivery formerly required skills at horsemanship (via the Pony Express), horsemanship is no longer a very useful employment skill. But some people still ride horses for fun, and some ham radio operators still use Morse code for fun.

In the early 1900’s, I’m sure there were “die hards” who believed that if young people didn’t learn to ride a horse, society would suffer. In the same way, there have long been “die hard” hams who believed the hobby would be trivialized if the Morse code requirement were eliminated, as it has been. For many of them, it was a test of dedication to the hobby. But many of those same old timers can’t find their way around the most simple microprocessor.

 

[Hedges]

Its my opinion that the mathematical representation of logic should not be abstracted away, even if it could be.

I carried a business card with ASCII code for years. Still need the codes sometimes programming things.
2's complement, gotta understand that, know if you're dealing with signed or unsigned.

I never had to deal with the number of electrons moving back and forth randomly and getting caught on one side or the other of a FET before. I was always dealing with buffered signals. But if you count single electrons, it turns out that every time you reset voltage on a capacitor, the number of electrons you get is different. If expected value is 1, then standard deviation of the probability distribution is 1; it goes as square root of mean.

Yea, I moved on to weird stuff beyond ohms law. But I still use ohms law daily. Representations of numbers and letters less often.

Gotta think of the electrical representation of logic and analog too. e.g. Flash these days has 8 electrical levels per cell, encoding 3 bits. And it still wears out with about 1000 writes.

 

[John Frum]

Of course, understanding how they inter-relate is very useful. Ohm’s Law, which goes back to the early 1800’s, is the algebraic expression that exactly describes how voltage, current, and resistance relate to each other.

Don’t know how that question relates, but our culture, and lists of important job skills, changes with technology.

Just as Express Mail delivery formerly required skills at horsemanship (via the Pony Express), horsemanship is no longer a very useful employment skill. But some people still ride horses for fun, and some ham radio operators still use Morse code for fun.

In the early 1900’s, I’m sure there were “die hards” who believed that if young people didn’t learn to ride a horse, society would suffer. In the same way, there have long been “die hard” hams who believed the hobby would be trivialized if the Morse code requirement were eliminated, as it has been. For many of them, it was a test of dedication to the hobby. But many of those same old timers can’t find their way around the most simple microprocessor.

You are probably correct.
At some point there will be coders that don't know what a bit mask or lsb/msb is.

 

[Hedges]

Of course, understanding how they inter-relate is very useful. Ohm’s Law, which goes back to the early 1800’s, is the algebraic expression that exactly describes how voltage, current, and resistance relate to each other.

Don’t know how that question relates, but our culture, and lists of important job skills, changes with technology.

Just as Express Mail delivery formerly required skills at horsemanship (via the Pony Express), horsemanship is no longer a very useful employment skill. But some people still ride horses for fun, and some ham radio operators still use Morse code for fun.

In the early 1900’s, I’m sure there were “die hards” who believed that if young people didn’t learn to ride a horse, society would suffer. In the same way, there have long been “die hard” hams who believed the hobby would be trivialized if the Morse code requirement were eliminated, as it has been. For many of them, it was a test of dedication to the hobby. But many of those same old timers can’t find their way around the most simple microprocessor.

I heard that a train crash once occurred because voice couldn't be understood over a poor radio link. Lower bandwidth communication (Morse code) would probably have gotten through.

What about the skill of reading a map? Using a sextant?
Can you imagine how our military is going to fare against an adversary who isn't stone-age, someone like China, who will promptly knock out all GPS navigation and targeting?

Ohms law will always be needed for electrical design and analysis, except when a particular sort of design is done with a tool that abstracts the problem. For instance, I used to do custom ASIC design, including analysis of layout and optimization of logic arrays. Today, you write VHDL and a compiler does the optimization. On LabView, you can do flow charts which are compiled to Verilog which is optimized and placed in an FPGA, to drive pins with real-time state machines. It is good to understand the design space well enough to know if a solution might be feasible before throwing it at a tool to generate a solution.

One of the more important ones, Commercial airline "Pilots" ought to know how to fly an airplane. Not all do.

 

[John Frum]

I was always dealing with buffered signals. But if you count single electrons, it turns out that every time you reset voltage on a capacitor, the number of electrons you get is different.

Ummm... who ordered the veal cutlet?

 

[MrM1]

Swimming in the deep end here in this thread.

 

[Johncfii]

I heard that a train crash once occurred because voice couldn't be understood over a poor radio link. Lower bandwidth communication (Morse code) would probably have gotten through.

What about the skill of reading a map? Using a sextant?
Can you imagine how our military is going to fare against an adversary who isn't stone-age, someone like China, who will promptly knock out all GPS navigation and targeting?

Kinda why I still like to practice Morse code. And my wife is a master horse-woman. Might be useful skills some day.

One of the more important ones, Commercial airline "Pilots" ought to know how to fly an airplane. Not all do.

Being a commercial pilot, I think that is not exactly true. Rather, what has happened to cause some terrible crashes is the pilots didn’t fully understand some of the arcane details of the automation. Or they forgot the right response under pressure. Or they got lulled into complacency and inattention.

 

[HRTKD]

There's a wiki page on ohm's law. But it's a catch-22, that is why would anyone visit it if they knew what it was or know to visit they didn't?

The very first entry in the FAQ index is the "beginner's video playlist", and the first entry there is electricity explained.


Ambivalent. It's like teaching someone binary for coding; it may or may not be useful. How many ham's actually use morse code every day?

I learned hex, octal, binary in college. One class in assembly coding. Never used assembly after college but have made extensive use of hex and binary. It seems most COSCI programs are more oriented towards AI than the lower level programming.

I can't memorize stuff very well unless I use it day in and day out. Having to memorize morse code and be proficient at it would be a significant barrier for me.

 

[Bob B]

In my youth and I was in the Navy .... which was a long time ago ..... when we got into company who would be rude and speak their native language to each other instead of english .... we would start to use pig latin or morse code to talk to each other.

 

[HRTKD]

In my youth and I was in the Navy .... which was a long time ago ..... when we got into company who would be rude and speak their native language to each other instead of english .... we would start to use pig latin or morse code to talk to each other.

Wait a minute, wouldn't you Navy guys just use flag semaphore, just without the flags?

 

[svetz]

Wait a minute, wouldn't you Navy guys just use flag semaphore, just without the flags?

Spoiler

decoder: https://www.dcode.fr/maritime-signals-code

 

[Bob B]

Wait a minute, wouldn't you Navy guys just use flag semaphore, just without the flags?

I have watched them do that .... but it is greek to me.