Understanding Electronics Basics #2

[KeepItSimpleStupid]

Make ground of the scope to be junction of C and L. Put a probe on the other end of C and l. Trigger on the Voltage across C or L.

Displayed V's should be in phase and the same amplitude.

 

[Muttley600]

I see you didn't get the sim them KISS?

Just finishing work for the day

 

[cowboybob]

Didn't notice the attachment was broken.

Here it is.

View attachment 62776

Let me know what you think. Post # 40 comments still apply.

Scope traces:

View attachment 62777

 

[KeepItSimpleStupid]

That's better. See if you can do a binary search on the frequency to see if you can get the amplitudes the same.
e.g try like 10 Khz. See which way things are going, then see if it's in the 0-1.5K or 1.5K or above. You should be able to zero in on the frequency where the amplitude and phase are the same.

I'm expecting a change in phase, but not sure.

 

[Muttley600]

AAAAAARRRRRRGGGGGGGGGHHHHHHHHHHH!!!!!!!!!!!!

**broken link removed**

ok guys, I'm stuck, I've been trying but I don't know what the highlighted bit means **broken link removed**

Is it 8 * the square root of 3
or 8 + square root of 3 **broken link removed**

View attachment 62780

hold on, think I've found something

Is this called a coefficent if it its in front of an operation & it means * by so first guess maybe right

not that I'm unsure or anything
Never mind this lot giving oscar an headache, why dont they use plain english **broken link removed**

PLEASE don't tell me it is simply 8/3

 

[KeepItSimpleStupid]

Easy:

The side would be sqrt(16*16-8*8) or the sqrt(192)

Now the part you don;t know which is called factoring.

192 = (2 * 2) * (2 * 2) * (2 * 2) * 3

Notice that there are 3 pairs of 2's and a 3.

If we were taking the square root, we can take out one of each of the (2 * 2)'s from under the sqrt()
so the √192 = 8√3

[latex]\sqrt{16^{2}-8^{2}}=\sqrt{192}=\sqrt{(2^{2})(2^{2})(2^{2})(3)}=8\sqrt{3}[/latex]

8√3 is approximately 8 * √3 = 13.85640646; 8√3 is the EXACT answer.

As a check: [latex]16^{2}=8^{2} +\left[8\sqrt{3}\right]^{2} [/latex] or [latex]256 = 64 + 64*3[/latex] or [latex]256 = 64 +192[/latex]

Does that make sense?

 

[Muttley600]

None at all.....eek!
But hopefully it will in the morning when I'm not tired an grumpy
Ill try again in morning
Night both

Can't stop looking at all those numbers, where did they come from?

 

[cowboybob]

I'm expecting a change in phase, but not sure.

Phase is shifted from 0° to -180° (or so: actually -174°) at about 1.59kHz. It then drifts on down to -180°s where it stays out to 10MHz and beyond (forever, in a manner of speaking).

View attachment 62781

This snip is with the "B" cursor at the 1.59kHz point. (Also 1K R1).

View attachment 62783

Close enough for me to call it a complete shift.

Note Frequency Phase shift shape and -174° point change frequency with a 100k R1:

View attachment 62786

Right at 100 times higher freq that for the 1K R1. Tell me RLC math doesn't work!!

On a roll. Changed R1 back to 1k and L1 to 10H. Still close enough for a reduction in -174° phase shift point to around 170Hz (more or less 1/10th of 1.6kHz). Ratios remain true (with a little wobble).

View attachment 62788

I'll stop now.

 

[KeepItSimpleStupid]

OK, so i was off by a factor of 10? Probably my head being affected by the rain! Now, we can go back to our regularly scheduled program and look at two traces at the one frequency?

You did enough for today. Graham, apparently did too. Me, I'm just getting frustrated learning the nuances trying to create a very complex label.

I never do anything easy. I'm making a label which is non-square where the outline template was in DXF. I then added the drilling guide for 11 holes of 1 size and 1 hole of another. I added some lettering and some symbols. I still don't understand layered drawings in the package I'm using. This label is probably 3" x 6".

So, I give it to a sign place and they made two labels for me. 1 laminated at $30 and one non-laminated at $20. They messed up. My PDF's could be enlarged without incident, but when they printed it, it was in a lower resolution than required and the writing looked blurred. I still learned that I can't use a drill and then ream the holes, but a pilot point bit seems to work. Tested on 1 hole. I gave the job back to them and give them 3 choices: 1) Do over; 2) Refund $ or 3) Refund $ and find out what they did wrong. They chose "do over".

I had printer issues and stack overflows when printing so i had to sort that out.

The plan was learning which I did. Now I have to find a better way. So I have to figure out how to put 3 labels on a piece of polyester. Find some white laser printable self-stick polyester. Find some clear as a "cold laminate". I asked Staples if they could laminate "one-side" and that was misunderstood because the operator never heard of laminating one side before.

I found some nice sterile, disposable, sharp biopsy punches that makes really nice holes in my polyester, so that's a plus. I tried two clear sheets and I like one better than the other.

I do like the expensive label's color of white, but not enough to be worth the cost. $30 for 1 vs about $2.00 for 3 if I make them.

I still don't know the "best way" yet. Punching will give me the cleanest edge on the label. A pilot-point bit can drill the label and the plastic case at the same time, but the edge won't be as clean. Laminated Paper doesn't drill well at all. It tears. I don't have a drill press.

Earlier, I did investigate having labels laser cut external and internal and printed. Not likely. Membrane keyboards are yuk. Conductive elastomer won't cut it at low volumes. All in all, a very slow learning process.

I can envision printing a paper label and applying releasable adhesive with a stick and apply to case. Mark the hole centers. Remove the template and throw away and clean the case. Punch the label. Apply label with self-stick back adhesive.

So, I learned something.

 

[KeepItSimpleStupid]

Graham:

I fixed up post #46 big time. It was a mess.

 

[cowboybob]

One of those days, eh KISS??!! I think the technical term for one like that is sucky.

OK, so i was off by a factor of 10?

No, you were right on it. I was playing with the component values.

 

[Muttley600]

I've works KISS's sum back right to first bit but can't see how he is getting the 4*4 at the very start, want to make sure I understand before relating it all to names

 

[cowboybob]

Which post are you referring to?

 

[KeepItSimpleStupid]

What "4"? It magically fixed itself. You know, auto correct.

 

[KeepItSimpleStupid]

No, you were right on it. I was playing with the component values.

I gave you R and amplitude to play with.

 

[KeepItSimpleStupid]

A few comments.

Mathematics is all about precision and following lots of rigorous rules. There are fundamental principles called proofs and corollaries. Answers in math generally have to be presented in a "simple form". The √192 isn't a simple form, 8√3 is. Using language that could be said as 8 radical 3 or 8 times the cube root of 3. It's even equivalent to 8 * 3 raised to the 1/3 power.

Historically, even when I went to school there were books of mathematical tables such as sqrt, cube root, logarithms because calculators didn't exist. The slide rule was king. I learned how to use one, but only barely. Calculators started to become into existence.

Factorization turns out to be an important skill. 9 when factored becomes 3 * 3 * 3, thus the cube root of 9 is 3.

In order to factor effectively, it is necessary to know about prime numbers and know the prime numbers up to a point.

All of this math stuff was a downfall for me because I can't memorize very well.

Mathematics is also good because it teaches discipline. In a lot of ways, I wasn't taught right.

There was one thing that would have helped more than anything else if I had learned it early, but it has little to do with math. That's penmanship. So yea, I think drawing and penmanship needs to be a very first basic skill.

My y's would look like x's when I printed them. Once I started to use script y's and script x's, a lot of my issues would go away.

Memorizing required much more effort for me. I did not realize that "I needed to be able to do the problems with the book closed".
As the courses got harder, memorization got more involved with less repetition. Repetition reinforced concepts early on.

I had to incorporate repetition in all of my classes. When I did, i got a 4.0 Grade Point Average.

 

[Muttley600]

What "4"? It magically fixed itself. You know, auto correct.

I'm not going to swear no matter how much you play me up * sticks tongue out* lol
Now it makes sense

Late for meal out for people leaving work, only just finishing

Later

 

[cowboybob]

I gave you R and amplitude to play with.

Already did with R and it had a predictable result (proportional freq response change).

Amplitude also had a predictable affect:

View attachment 62809

I.E., none.

 

[KeepItSimpleStupid]

CBB:

I was actually joking.

I still didn't see the expected results of equal amplitudes, but "out of phase"? across the inductor and capacitor.

Graham:
Good. Now you really know how rain plays with my head. Good job, BTW.

 

[Muttley600]

Just back in at 00:50 eek! Never mind, havent got to be at work til 7am that gives me about 5 hrs sleep but looks like more than KISS is getting.
Back to it tomorrow & finally making sense of it all