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Understanding Electronics Basics #1

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hi M,
With all this new knowledge why don't you try out some the quizzes, here: https://www.electro-tech-online.com/tools/

E.:D

erm, according to that I have no knowledge, 2 out of 10, thankfully I hadn't heard of most things so I was guessing, I'd have been more upset if it was things I'm meant to understand by now

cbb:

Change the CVS to a CCS in the sim.

Muttley:
DEF: The world of electronics defines rise-time as the time it takes to go from 10% of the final value to 90% of the final value.

What does it achieve by knowing the times, is this the phase cycle again
 
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Your capacitor one. Remove R and replace the CVS with a Constant Current Source.

OK.

View attachment 61553

Never done this. The CCS is 10ma.

I notice the voltage climbs to remarkable levels (10,000 VDC in the example) in 1 second. Totally flat rise with no apparent end;

View attachment 61554

1,000,000 VDC at 100 seconds. Very, VERY linear. Course, it blew out my monitor... pieces all over the place------

Not sure of the significance of what I'm seeing??!!!
 
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erm, according to that I have no knowledge, 2 out of 10, thankfully I hadn't heard of most things so I was guessing, I'd have been more upset if it was things I'm meant to understand by now

I took them just now, also. Did not get 100%, I can assure you.

Interesting task, though. Good for the brain (and one's humility meter...).

Thanks for the impetus, Eric.
 
Remember, I said that the capacitor initially acts as a short circuit when a voltage is initially applied?

Now your gonna wish you han't brought that up **broken link removed** I don't know if you were around for my original question about getting a led to light up off a jack plug, CBB gave me a circuit with what I would class as a short, I struggled & struggled to get my head around it so much, I gave up & took his advice, built it for real & it worked, so the only thing I know now about shorts is sometimes if the value is small enough they seem to be ok, so know I know your both itching to explain your interpretation of a short compared to mine, which was putting a + & - together, it seems with components involved this is acceptable

The impact of this derivative thing is that it changes the phase angle of the voltage when we talk about sine waves. The derivative of the sin(x) is the cos(x), hence you can see a huge phase shift in the voltage.

Still aren't there but I'm sure we will get there

This phase shift makes inductors and capacitors very different from all other electrical components.

So are you saying only caps & inductors are capable of phase shift **broken link removed** now this is what I call a basic understanding, which is what I was after before delving into math

While I'm thinking of it, here's the oscillator I spoke of. Something to play with this weekend.
View attachment 61411
Enjoy!

Just about to have a go at this now
 
Never done this.
I notice the voltage climbs to remarkable levels (10,000 VDC in the example) in 1 second. Totally flat rise with no apparent end;

Well, you know he's going to show us a rise over time, all we gotta do is play with values to get there, flat line means we can't see enough time so lower the cap value or extend the time, one will work **broken link removed**

1,000,000 VDC at 100 seconds. Very, VERY linear. Course, it blew out my monitor... pieces all over the place------

Not sure of the significance of what I'm seeing??!!!

The fact you can with screen blowing up in your face **broken link removed**

Good for ones humility meter...
Thanks Eric.

Thats me sorted then if low score = humble, I did well, as humble = content with life for what it is **broken link removed**

Eric seems like a decent mod doesn't he **broken link removed**
 
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Yes he does. Very calm.

And KISS, I see what your saying. Surprising that the sim let me do it. No error messages.
 
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And KISS, I see what your saying. Surprising that the sim let me do it. No error messages.

do what **broken link removed** hold on, he was telling us if you had a constant, this time thing wouldn't work with a cap, or is he just showing us a constant is infinate & has no rise that can be worked with, it cannot be manipulated from what it is, yes, I've played too **broken link removed**

In opamp oscillator example, what component is a opamp, a transistor **broken link removed** or something we haven't covered

Ok, so it works with small input leads but has one large output lead & I haven't seen it discussed here yet until now, it is basically boosting the signal
 
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Quiz time (capacitor and current source)
1. Why is it linear?
2. Why didn't it stop?

Yes, capacitors and inductors can mess with the phase of v(t) and i(t)
 
In opamp oscillator example, what component is a opamp, a transistor ... or something we haven't covered

The "pyramid on its side" icons marked OP1 and OP2 are the OpAmps. There are no transistors. Z1 and Z2 are zeners and everything else you should be able to recognize.

I realize this is a complex schematic. Just take your time constructing it. Don't forget to use the "Analysis", "ERC" function to check for wiring errors.

BTW, in the ERC window, if you click on the error text, it will highlight the item that's a problem.

hold on, he was telling us if you had a constant, this time thing wouldn't work with a cap, or is he just showing us a constant is infinate & has no rise that can be worked with, it cannot be manipulated from what it is

Not exactly. Two different concepts here.

What he was referring to was the fact that in the very first instant that a voltage is applied to a capacitor (NO resistor in the circuit), the cap acts as (or exhibits) a dead short. In other words, maximum current will flow. But ONLY for that very first instant in time. The current flow starts to decrease immediately after that moment. The sim showed a line of charge that in real life simply could not happen.

In real life the cap will charge to a certain voltage level (the current decreasing the whole time)l and then the charging will stop (for all intents and purposes).

And keep in mind that a constant should always be thought of as a "fixed" (unchanging) value. A resistor has a fixed value (constant) (so long as its temperature remains steady). In a formula, like: X=2x+4, both the 2 and the 4 are constants (you can't make a 2 anything other than a 2).
 
Quiz time (capacitor and current source)
1. Why is it linear?
2. Why didn't it stop?

Yes, capacitors and inductors can mess with the phase of v(t) and i(t)

there's no point altering cap value V if there's no R (load) because it isn't drawing anything there's nothing there really, we are just seeing the I plodding away on graph because we've told it to & Added I by source which shouldn't be possible really without a load

That's my best guess :-/

I was seeing a constant as zero & infinate, but as CBB is saying maybe constant can be anything you make it (but that doesn't add up in my head) because if you have anything other than a flat line = 0/infinate you are going to be able to alter f(x) with the cap value for V even if R is missing you should be able to limit the V potential shouldn't you?

So even with my horrific understanding, any constant should give you a FLAT line not rising, even linear
 
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Remember that:

[latex]i(t)=C\frac{dv(t)}{dt}[/latex] so now

we made i(t) = k

so [latex]K=C\frac{dv(t)}{dt}[/latex]

then we end up with

[latex]Kdt = Cdv[/latex]

Integrating both sides and knowing that at t=0, v=0 we get

Kt = CV

So, V = K/C * t; which is a straight line

The reason why v(t) infinitely increases is because there is no voltage compliance on an ideal current source.

So, you just learned how to create a linear ramp.
 
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CBB:

Fire up your SIM again. This time with an inductor. Look at v(t) with a constant voltage source and a constant current source. This time the constant current source, I think, will require the resistor. Look at v as a function of t.
 
Well I'm certainly going to remember what an ideal current source is, jumped straight outta bed & turned phone on to find out the answer.lol
So really as CBB said, it's not really possible, but what you have done is actually give me a math sum that I can understand.........Yippee :) so now I can start to relate these letters to something so it as as follows:
i(t)=C dv(t) is simply your making Y axis = C & it is over 'di' as the other part of the equation, so K=C is simply taking both Y & X axis = i(t)
So Kdt = Cdi is saying the same thing, ignoring the reason for 0 & concentrating on sum for a moment:
Kt=CV is the same thing again, just taking the d out
So V=K/C*t is simply saying the V=time divided by volts times t & because there's 0v, ahhhhhh I see, there's no v potential at the source, so the cap doesn't work......god I'm thick.lol
So that killed part 2 of my answer on post #152

Hence the source is uncontrolable & infinite, but it's not aflat line like a normal constant because I was being generated (even if it's not possible, it makes sense in my head.lol)

Sorry, I got there I the end :)
 
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So first sim similar as there's no I, second has jump as it creates the mag force but then hasno V potential so cannot conduct & is showing us 0V, did KISS say try second with a resistor

MorningCBB:)

So what are those funny numbers representing, why do they have an E in them?
 
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second has jump as it creates the mag force but then hasno V potential so cannot conduct & is showing us 0V

Actually, it initially has a huge V but for a breathtakingly short time (one of those zero time anomalies one sees in math proofs).

did KISS say try second with a resistor

View attachment 61568

As you can see, no difference. The resistor is, essentially, not there.

So what are those funny numbers representing, why do they have an E in them?

It's engineering notation. Basically a way to "short hand" very large (or very small) numbers: it eliminates the huge strings of zeros. The first number in the time axis of the CCS sim is 10 raised to the -15th power, or 10/1,000,000,000,000,000, or 0.000000000000001 seconds (a vanishingly small time). In actuality, it's instantaneous and only happens in the math solutions. Not so much as not real as "ideal", i.e., you'll never see it in the real world.

See for a more thorough explanation:

https://en.wikipedia.org/wiki/Engineering_notation

And mornin', Graham.
 
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Not exactly what I was expecting. This might help better: Anyway, you can see that using a current source, the current is almost unbounded. It's a narrow pulse. The inductor stores energy and then releases it.

Might try putting the measured current on the x-axis, rather than voltage.
 
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