I'm at a loss to describe my feelings on KCL, or even what it is. Fortunately I don't remember. It's probably at the core of simulator technology, in addition to matrices. Something to do with things adding up to zero, which sounds awfully like circuit analysis in model land. The type of circuits we draw with long lines representing zero length connections.
- Speechless -
I troll in jest. But not really, because it's true.
There's a KVL? That is the hint I needed to remember what the "C" is for in KCL, it might be coming back to me a bit more. My mind was going to potassium chloride, wondering if the standard production process is carefully dropping a kilo of potassium into a bucket of hydrochloric acid and hoping it doesn't fizz too much. The name Kirchoff I do remember, as in "good day sir, I need to sneeze, would you be so kind as to lend me your handkirchoff ... very well, you can have it back now" - an inter-pandemic conversation perhaps from a century gone by. I remember it in the plural "laws". There was Thevenin and Norton, I do know what those are, but even now it reminds me of the stuff of dreariest lecture - dreary being a contraction of "dry theory" (I assume). My mind still drifts to a brand of silicon carbide doused icecream (when I was little I used to dip my icecream in the beach for extra crunch, so it has physical precedent). You get the idea - this stuff was passing monotone and I forgot it, through cramming for exams and decades of entire disuse.
Having done the right thing by my educators (by focussing solely on their material for 3 days and actively forgetting all other topics) and by myself (by forgetting something that has proven to be literally useless to me and all those around me) I can feel a sense of achievement and enlightenment - bsfeechannel put it best in the words "pride of ignorance". Perhaps the highest principle of engineering - to know that you don't know what you don't know. A badge of honour to be worn by those who have toiled through the years to arrive at a place where knowledge works and even one's mistakes seem less frequent.
I genuinely don't remember what KCL and KVL are, beyond that stated above. Taking a hint from "things adding up to zero", and without looking I'll guess:
guestulate 1: the sum of all currents into and out of a node is zero.
guestulate 2: all voltages around a loop add to zero.
I've got a feeling this is right, but remember I am unqualified to take a side in an argument (well, technically not, but that's splitting hairs). I have guessed at my knowledge. But I can make some observations on this interpretative ignorance:
1: All the currents going into or out of a node equals all the current going into and out of a node.
2: The sum of voltages around a loop of by definition zero voltage, is zero volts.
To really boil it down for meaning:
1: Insulators are insulating.
2: 0 = 0.
In the real world, voltages are quantised in irregular discrete levels like 1V8 3V3 5V, 12V, 24V, 48V, 110V and range all the way up to a million volts. A supply rail is established by buying something or designing something like a SMPS, from that all manner of contraptions draw their power, currents flow as a result of series and parallel connections, RF only emits from approved modules, the board rolls through the SMT line, and the customer is delighted.
No, I'm not pleased by that when taken to its button-pressing extreme. But I've never thought of running a 3V3 chip from a -3V3 reg (or really vice versa). I've never known enough to fear current leaking from some insulated node by a magical route. I've never known there was a limit as you move to RF and fields. I simply never took it on board. I learned from what works.
Computers yes. Historians yes. It is interesting in those contexts and should be taught. Not core syllabus, it is not the stuff of understanding and absolutely not real world (in my experience). (To be fair, the lecturer may have done the material right, by saying the academic equivalent of "yeah nah, you'll probably all be using simulators in the future, so you will probably never use this, but this is how they work".)
If I'm wrong in my guesses about KCL / KVL then I mean generally "something like that", and note that not knowing or having them correct has not done me any harm that I know of.