Revision of Circuits and Electronics Part 1 - Superposition, Thévenin and Norton (lecture 3)

What are the properties of  a linear circuit? It has homogeneity and superposition properties.

Homogeneity means a proportional input and output.

Superposition involves -

(1) Finding responses of the circuit to each source acting alone.

(2) Summing the individual responses.

This applies to independent sources.


Thevenin's Theorem -

VTH  -  Open circuit voltage seen at the terminal
RTH -     Resistance of network seen from the port.


Norton's theorem  -
 IN  -  -Short circuit current seen at the port
RN -     same as Thevenin's resistance

Video: - http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-002-circuits-and-electronics-spring-2007/video-lectures/lecture-3


Lecture notes : -  http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-002-circuits-and-electronics-spring-2007/lecture-notes/

Revision of Circuits and Electronics Part 1 - Circuit Analysis Toolchest (lecture 2)

KCL and KVL are basic methods but nodal analysis is now quite popular. The steps are:-

(1) Select reference node (ground) from which voltages are measured

(2) Label voltages of nodes w.r.t. geound

(3) Write KCL for the nodes

(4) Find required voltages and nodes.


Video: - http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-002-circuits-and-electronics-spring-2007/video-lectures/lecture-2/


Lecture notes : - http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-002-circuits-and-electronics-spring-2007/lecture-notes/

What's Buzzing?

I was doing all the things that an independent artiste should do - registering for Soundexchange and trying to get my music on radio. The process takes time as Soundexchange may take up to 30 days to reply.

I am glad I am back to doing some electronics again. It's a tough subject so I  am going slow with it. 

Revision of Circuits and Electronics Part 1 - Lumped Circuit Abstraction (lecture 1)

Suppose we wish to answer a question like-
What is the current through a bulb?


 We could do it the hard way  with Maxwell's equations or the easy  way where certain conditions are ignored. So to do it the easy way, replace the bulb with a discrete resistor and use Ohm's law to find the current. The discrete resistor becomes the lumped element abstraction of the bulb.

From Maxwell's equations, a problem arises where  the rate of change of charge w.r.t. time may not be equal to zero when finding the current.

(1) To be unstuck from this problem, we have to make it equal to zero!

(2) The voltage also needs to be defined and for this, rate of change of flux  w.r.t. time outside the element is equal to zero.

(3)Signal speeds should be less than the speed of light.

The above is not really true in general but  is the playground for EECS.


KVL- sum of voltages in loop is zero
KCL- sum of currents in node is zero



Video:-
http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-002-circuits-and-electronics-spring-2007/video-lectures/lecture-1/



Lecture notes:-  http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-002-circuits-and-electronics-spring-2007/lecture-notes/

Emily Scholz - Other Side Of The Screen

This is one of the best songs from an independent artiste. Hard to believe she is more into comedy.

But sometimes I guess you got to do the things that you love most.

The song is out on CD Baby!

The song is now out on CD Baby. Here is the link to it:-

http://www.cdbaby.com/AlbumDetails.aspx?AlbumID=aethesarapagroup&_ga=1.178230759.355093202.1451974414

I decided to take the independent route and it has been quite an adventure so far. I don't expect the sales to take off very quickly but artistically I think we have done a pretty good job. Someone on my Facebook has listened to the preview and said it is a really nice song  - but she doesn't seem to have bought it yet though - so there you go.

I did manage to listen to some great music while taking this route so I will probably post at least one of them later.

The Open Song Project - "You Bring Out The Best In Me"

I wrote the song and my brother Tim arranged the music. He always seems to be able create some kind of magic with the piano. He has zest in music whereas I am kind of like a little more into sport. Anyway, this is an open project which means others can try to improve on it. I am not really sure if this song is complete so I guess additional lyrics and music could be added to it.I think my bro has missed out a line near the beginning but for starters, I think it is  good enough for the most part. The lyrics:-

You bring out the best in me
You mean all the world to me
Took my heart and took my soul
It's the greatest love I know
You bring out the best in me

I just want to be with you
Hold my hand and we will see it through
You bring hope in all my ways 
Light in all my days
You bring out the best in me




Update 3-1-2016: The song has been completed and the the project is generally considered closed. It has been been completed by my nephew in law (nephew of Tim's wife) . These things do happen sometimes I guess! We will be sharing songwriting and music credits with him and his band.  His full name is Ae  (Phumthep Pholwat) from Thailand and the band is a college one called the Sarapa Group. 

 We are now looking into the promotional stage of the song.