Understanding Electronics Basics #2

[KeepItSimpleStupid]

Nice vid. The manual ways of calculating angles is obsolete. The common angles were commited to memory like 30, 45, 60, 90 and integer multiples to 360 degrees. The functions were available in books of tables. The second way was to use the "slide rule". See: **broken link removed**

Interpolation had to be used to calculate values that were not in the table and is used today. Suppose you had the following table.
x y
1 4
2 8

If you wanted the value of 1.5, you could interpolate and get 6 for y. It's like noticing that 1.5 is 1/2 the distance between 2 and 1 and therefore the Y value is 1/2 the distance between 8 and 4 so you get 6.

Computers can do it using something called an "infinite series" (we are not going there) and micros could use a lookup table or an infinite series.

There is an identity that can help as well: [latex]sin(x)^{2}+cos(x)^{2}=1[/latex]

I won't take "interpolation" further than this unless you want to. It's easy.

 

[Muttley600]

That's a great story in link
You mentioned using memory & I had this sudden urge to love my calculator.lol

Interpolation sounds sensible

I can see cosine @ 1 means phase is starting in a different place, just need to relate it to circle now

I just got what R^2 means.......*grin* it's starting to make sense

Well, that didn't last long, are you saying a parametric plot is length rather than a circle?
It can't be can it because you were showing me circles?

Ok, just got the second equation, that funny looking zero θ for X&Y means they are one apart & it equals a full circle or 2∏

Questions while i move onto next sim off CBB
Where did z come into this, have we covered k in with this?
I know we mentioned them before but trying to now use bricks made into small wall if that makes sense
Oh, & the little n

 

[Muttley600]

ok, have knocked up sim, now to play with values, very low output so I'm going to see if I can boost it?

View attachment 63022

ok, first thing I went for was the load, V changed as I changed load, how do you make V steady, no matter what the load **broken link removed**

 

[Muttley600]

Just concentrate primarily on the sine and cosine and tangent. It should be easy.

I won't take "interpolation" further than this unless you want to. It's easy.

I've heard that one before **broken link removed**

but to be fair, I'm not going to forget it in a hurry, what do you think of my screen on phone **broken link removed**

View attachment 63025

 

[KeepItSimpleStupid]

Anyway θ is generally used to denote angles and it's also used as the "arguments" to, for instance, the sin(θ) function. θ can be in degrees or radians and other similar units.

"Parameter"
I could not find a simple definition, so I will use an example. When you looked at two waveforms on the SIM that were related in time and lets call them CHA(t) and CHB(t); t is a parameter for both channels. It relates both together.

Yea, but Oscar's headache is more appropriate.

 

[Muttley600]

"Parameter"
I could not find a simple definition, so I will use an example. When you looked at two waveforms on the SIM that were related in time and lets call them CHA(t) and CHB(t); t is a parameter for both channels. It relates both together.

oh, I thought it was the outer limit of something, a point that something could not pass?

"Yea, but Oscar's headache is more appropriate.

just the way I've remembered it now, main thing is I do **broken link removed**


Whats happened to CBB?

 

[cowboybob]

Still here. I've been going thru the 2 xsistor SMPS sim trying to get it to oscillate for two days...

Finally got there. You might note I had to play with component values a lot but at least it's behaving as I understand a SMPS is supposed to.

View attachment 63034

Not as well as the original designer claimed, but getting there. This is remarkable, to me, that it works as well as it does.

It has a fairly narrow input voltage window, and not awesome output voltage control, but for what it is, and how much power it dissipates as waste is pretty sweet. At least as far as I can tell.

Play with the input level (say 11 to 15VDC) and watch what happens. Same with the load. Like I say, a narrow control window, but I'm impressed...

I also adjusted the Scales of some of the transient traces to emphasize, for instance, the ripple present on the output. Note it ain't much.

Can you cipher from of the X-axis numbers what frequency the circuit is oscillating at?

 

[Muttley600]

Need to be on computer for frequency as all my folders are on there, But as always, willing to try

0.25 p-pV \ 0.03 λ = 8.333333333333333Hz ?????????

I'm now thinking that should of been kHz

Let's try again, I'm going to shoot whoever invented the decimal point.lol

0.25V / 0.3mS = 0.8333333 kHz

I can't double check without folder so you let me know how far I was out......

 

[cowboybob]

Huh??

Remember, just 1 cycle's period to determine freq. I haven't tried the LC method, but it ought to be close to the period method.

Maybe this will help:

View attachment 63035

 

[Muttley600]

Sorry, I was working off VF3 output frequency
I'll have another go after walking bobby as that's totally different.lol

1/27.8u = 0.03597MHz

Q: why is YA-YB showing 150.72mV when looking at graticules @ 5V each, looks like 13.5V?
Is it because cursor lines aren't lined up?

 

[Muttley600]

Well, looks like that was wrong by lack of response

& that's me for tonight, back tomorrow

 

[cowboybob]

Sorry, I was working off VF3 output frequency
I'll have another go after walking bobby as that's totally different.lol

1/27.8u = 0.03597MHz

Q: why is YA-YB showing 150.72mV when looking at graticules @ 5V each, looks like 13.5V?
Is it because cursor lines aren't lined up?

For frequency, yes, good! But maybe 35.97kHz might be easier to read and say.

A: Yes, they wouldn't line up exactly.

Doesn't look like the LC method will work - too many other C values in play. Actual, measured freq is a better method for this circuit.

 

[Muttley600]

So I was wrong, I gotta learn to get it right

Be nice to get to the point where it becomes second nature

Morning KISS

 

[cowboybob]

So I was wrong, I gotta learn to get it right

Be nice to get to the point where it becomes second nature

Morning KISS

Wrong about what?

 

[Muttley600]

The frequency, think I need to practise once a day, every day until it becomes second nature

Sorry, morning CBB

 

[cowboybob]

Mornin', Graham.

Interesting thread that mirror's ours here.

Graham, I'll have to hand it to you for hanging in there since the beginning (you, too, KISS).

It's always curious to me how easy it is to forget when you knew little or nothing about a subject, but were vastly curious about it.

Some of us have a tendency (myself as well, at times) to to display our vast knowledge (as we perceive it) rather than try to understand, or remember what it was like when we knew absolutely nothing.

Not even a clue on what question to ask.

And how easily we were dissuaded from asking any more questions when the answers were so deep that we were made to feel utterly stupid for having asked it in the first place.

I guess, like most forums, that some people just can't keep themselves from wanting to be the final word in what is correct.

No matter that an OP has long since lost the desire to learn anything more about a subject, now that he has been made to realize that he'll never be able to understand anything so utterly complicated.

<EDIT> Incidentally, your freq answer was absolutely correct. I only commented about the answer's format. You can use whatever format you choose. Conventional formatting isn't a rule, only a guideline...

 

[Muttley600]

Link broken CBB

I love what I'm learning, I didn't expect a complicated math lesson but if that's part of the package, so be it, I do struggle simply because Ive never heard of things, but struggling has its Benifits too, it just makes me even more determined
I have had moments where for a brief second, I have thought of quitting
i.e. when KISS originally threw loads of formulas at me, when I try to understand the math, then start looking too deeply.....It is simply overcome by trust in the end, I owe both yourself & KISS a great deal for not giving up on me when you realised I was lacking in quite basic skills, I have learnt to trust you both have good intentions to help where others might have just pointed me in a different direction, what you are both giving me is priceless & I feel I made two very good friends, I like the whole thing of learning/humour & lessons along our path, it is a nice balance.
I still try to help myself understand, but looking at the whole story us still a very scary prospect.eek!
A perfect example of this was me trying to decipher things into degrees, I had to spend two days on a children's math site, I kept seeing the whole picture & thinking what have I done, I finally found that YouTube vid of what I actually needed to know to work out degrees, it was all of about 3mins.lol
Then I continued with KISS's links & a day later I would have got to it anyway......sigh

My story is very slow & small steps, looking at something the first time to give me a basic concept, then at some point in the future it crops up again & because I have basic idea in place that is when I'm curious to know more, I don't end up with information overload that way & actually get to enjoy learning something (a first for me)

I'm happy to ask daft questions otherwise my understanding could end up wrong & I trust you both to correct me, even if it is only formatting ;-)

Thanks both

 

[cowboybob]

Interesting thread that mirror's ours here.

This one works...

 

[Muttley600]

Wow, how lucky was I to get you two *grin*
I would have legged it too.eek!

Post #25 sticks in my mind but the rest lost me on the first page, as a learner I disagree with comments about being able to find answers, I have tried, it doesn't mean I understand either what to look for in the first place or even understand if I find the solution, we might be at this for a few years.lol

But hey, they are just my thoughts, no offence meant, forums are for everyone to enjoy in their own way, maybe instead of charging in, it would be good for the wise ones to ask where the newcomers knowledge starts, so they can reply at a level to keep their interest

 

[cowboybob]

Exactly...

#24 was also on the mark.

And, thank you.