Re: Omega

On Sun, 30 Jun 2024 07:38:19 -0700, john larkin wrote:

On Sun, 30 Jun 2024 14:23:24 +0100, Cursitor Doom <cd@notformail.com>
wrote:
 

On Sun, 30 Jun 2024 06:05:41 -0700, john larkin <jlarkin_highland_tech>
wrote:
>

On Sun, 30 Jun 2024 08:44:34 +0100, Cursitor Doom <cd@notformail.com>
wrote:
>

Gentlemen,
>
For more decades than I care to remember, I've been using formulae
such as Xc= 1/2pifL, Xl=2pifC, Fo=1/2pisqrtLC and such like without
even giving a thought as to how omega gets involved in so many aspects
of RF.  BTW, that's a lower-case, small omega meaning
2*pi*the-frequency-of-interest rather than the large Omega which is
already reserved for Ohms. How does it keep cropping up? What's so
special about the constant 6.283 and from what is it derived?
Just curious...

>
2 * pi.
>
If a thing 1 unit in radius rotates one time per second, its
circumference is 2pi so its rim velocity is 2pi/second.
>
A capacitor current depends on the rate of change of the voltage.
>
 I = CV/T
>
A 1 volt peak 1 Hz  sine wave has its max rate of change at the zero
crossing, and that rate is 2pi volts/second. So 1 farad driven with a 1
Hz 1 volt peak sine wave has a peak current of 2pi amps.
>
You can Spice all that to get a feel for things.

>
Thanks, John. This is the fundamental stuff I just overlook since the
need for it so rarely crops up. It's easier to take an abstraction level
higher and lose all the vital detail in the process.

 
It's good to understand the basics, but I mostly use Spice these days,
even for simple things like voltage dividers.
 

You're up early today. Off to church are we?

 
No, I just woke up early with a zillion ideas. That happens some times.
 
Today is San Francisco Pride Day (Dikes on Bikes and such) so it's a
good day to stay close to home. Traffic and parking and everything will
be a nightmare.
 
https://sfpride.org/parade
 
https://www.dropbox.com/scl/fi/j698pjo7jxm152zuzu4dx/Pink_Triangle.jpg?

rlkey=n4xinzzm39bms9w04syb7egkx&raw=1

I went to one of those once in Berlin when I lived there. God almighty!
I've never seen such a complete and utter freak show in my entire life. I
just stood there gaping open-mouthed at the procession. It must have been
pretty obvious to any of those weirdos on the floats that I wasn't there
to celebrate them! I just find it bizarre that parents actually take their
kids to see this sort of thing and they're all waving their rainbow flags
and whatnot. No kids of mine would be allowed within a million miles of an
event like that. No wonder the God-fearing folks reckon the world's going
to hell in a handbasket. :(