EEVblog Electronics Community Forum

Electronics => Projects, Designs, and Technical Stuff => Topic started by: John Heath on October 07, 2018, 08:55:31 pm

Title: -The elegance of the dynamics of electronics
Post by: John Heath on October 07, 2018, 08:55:31 pm
I was watching a video on wave theory from the 1950s. This video always puts a smile on my face. I wanted to share this smile with others in this group. This guy really understands the great contribution of Oliver Heaviside's book " telegraphers hand book" from 1890. Enjoy.

https://www.youtube.com/watch?v=DovunOxlY1k&t=171s (https://www.youtube.com/watch?v=DovunOxlY1k&t=171s) 
Title: Re: -The elegance of the dynamics of electronics
Post by: Wolfgang on October 07, 2018, 11:38:58 pm
Very nice film !
Title: Re: -The elegance of the dynamics of electronics
Post by: John Heath on October 08, 2018, 08:27:45 am
I like the part where a sudden impedance change in the middle will cause an expected reflection but the gradual impedance change that is as long as the wave length acts like an impedance matching transformer with no reflection. I wonder if that technique for impedance matching has ever been used in electronics. I can not think of an example of it.   
Title: Re: -The elegance of the dynamics of electronics
Post by: T3sl4co1l on October 08, 2018, 10:14:45 am
Quote from: John Heath on October 08, 2018, 08:27:45 am
I like the part where a sudden impedance change in the middle will cause an expected reflection but the gradual impedance change that is as long as the wave length acts like an impedance matching transformer with no reflection. I wonder if that technique for impedance matching has ever been used in electronics. I can not think of an example of it.

Easily found, :D
https://www.microwaves101.com/encyclopedias/tapered-transformers (https://www.microwaves101.com/encyclopedias/tapered-transformers)
https://en.wikipedia.org/wiki/Horn_antenna (https://en.wikipedia.org/wiki/Horn_antenna)
https://en.wikipedia.org/wiki/Vivaldi_antenna (https://en.wikipedia.org/wiki/Vivaldi_antenna)
etc.

Tim
Title: Re: -The elegance of the dynamics of electronics
Post by: Wolfgang on October 08, 2018, 10:52:20 am
Of course it exists. Is called tapered transformer. Can be used for striplines or waveguides.
Title: Re: -The elegance of the dynamics of electronics
Post by: John Heath on October 09, 2018, 12:29:52 am
The best analogy I can think of for the tapered type micro wave impedance matching would be a bull whip. As a wave travels down the bull whip the whip diameter is becoming smaller therefore inertia is less , less inductance , which will increase wave velocity. By the time the wave reaches the end of the whip the velocity is really fast causing the snapping sound at the end where the whip stops.