Custom Search
Over 9,000 pages indexed!
|
| Your Host |
 KirtBlattenberger ... single-handedly redefining what an engineering website should be.
5CCG (5th
MOB): |
|
Hobby & Fun Airplanes and Rockets: Equine Kingdom: Doggy Dynasty: |
| ||||||
| ||||||
| Thevenin Equivalence Question - RF Cafe Forums | ||||||
|
Because of the high maintenance needed to monitor and filter spammers from the RF Cafe Forums, I decided that it would
be best to just archive the pages to make all the good information posted in the past available for review. It is unfortunate
that the scumbags of the world ruin an otherwise useful venue for people wanting to exchanged useful ideas and views.
It seems that the more formal social media like Facebook pretty much dominate this kind of venue anymore anyway, so if
you would like to post something on RF Cafe's
Facebook page, please do.
Below are all of the forum threads, including all the responses to the original posts. themaze Post subject: Thevenin Equivalence Question Posted: Wed Aug 24, 2005 7:50 am Lieutenant Joined: Wed Aug 24, 2005 7:43 am Posts: 2 Hello all- I am studying for my PE after 20 years away from school... In a very simple circuit of a dependent current source (value= .75* voltage across resistor) in parallel with a resistor of 4 ohms, how would one compute the equivalent Thevenin resistance of that circuit (measured across the parallel combo). Yeah, I know it's probably very simple... The answer is -2 ohms, I'm told. Not sure how to arrive at that answer... Thanks Top john-ee Post subject: Posted: Wed Aug 24, 2005 11:32 am Lieutenant Joined: Tue Aug 23, 2005 6:33 pm Posts: 3 You need to think out of the box on this one. Since you are dealing with a voltage-dependent current source, you need to to know what the voltage across the 4ohm resistor is in order to get the source's current value. Try applying a 1V independent voltage source across the output (i.e. parallel to the 4ohm R). Then you know that Vresistor = Voc = 1V. That means that Iresistor = 1V/4ohm = 250mA. Also, Idependentsource will be 0.75A*1V = 750mA. The remaining 500mA will flow through your 1V source at the output and be considered your Isc. So, Voc/Isc = 1V/500mA = 2ohm. This result is dependent upon the position of the current source. If, in normal circuit convention, the arrow points up, then the above answer is correct. However, if the arrow points down, the current flow is reversed, and Isc becomes negative. This may be why you are told the answer is -2ohms. Good luck with your PE! -John- Top themaze Post subject: Thank you so much!Posted: Wed Aug 24, 2005 1:25 pm Lieutenant Joined: Wed Aug 24, 2005 7:43 am Posts: 2 Great clear explanation- Many thanks- Neil Posted 11/12/2012 | ||||||
| ||||||
|
Please Support My Advertisers
|