Path: ...!Xl.tags.giganews.com!local-2.nntp.ord.giganews.com!nntp.supernews.com!news.supernews.com.POSTED!not-for-mail NNTP-Posting-Date: Sun, 30 Jun 2024 14:38:19 +0000 From: john larkin Newsgroups: sci.electronics.design Subject: Re: Omega Date: Sun, 30 Jun 2024 07:38:19 -0700 Message-ID: References: User-Agent: ForteAgent/8.00.32.1272 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 55 X-Trace: sv3-a0LMgAfyqXnRPem8OXzhEUx/rCzpSj4lq3ORdaxiPWIWzqFgfNtRoKccYiIvO2pSJEvM4DSwWn2BzlK!AGAORFFlOTAv+6LduW2wOEEu70fuzehtYIPZuyGRom5IjLcuRNGmfkTn4YJ8cAR04ObLVsMZGgbN!BHeqMA== X-Complaints-To: www.supernews.com/docs/abuse.html X-DMCA-Complaints-To: www.supernews.com/docs/dmca.html X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 Bytes: 3141 On Sun, 30 Jun 2024 14:23:24 +0100, Cursitor Doom wrote: >On Sun, 30 Jun 2024 06:05:41 -0700, john larkin > wrote: > >>On Sun, 30 Jun 2024 08:44:34 +0100, Cursitor Doom >>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