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Eddy boy • Nov 3, 2008

# Current and voltage source

In circuit analysis, what is the difference between voltage and current source ??current exits only when there is some potential difference then why we say only current source ?solve it!😕
Eddy boy • Nov 4, 2008
If any body know a good book of circuit analysis/electric circuit then plz tell me.
rohit.kush • Nov 4, 2008
network analysis and snthesis by "chakrabarti"
gauds • Nov 5, 2008
"Fundamentals of electric circuits" by Alexander and Sadiku
Eddy boy • Nov 5, 2008
oh! its too difficult to select which one book is perfect for me.

Gauds please tell me about the contents of fundamentals of electric circuits
gauds • Nov 5, 2008
It is divided into three parts,Dc circuits,AC circuits and Advanced circuit analysis.

DC circuits-basic laws,theorems,op-amps,L,C,first-order and second-order circuits,node and mesh analysis.

AC circuits-Phasors,source transformation,three phase circuits,power analysis frequency response,mag coupled circuits,

Advanced circuits analysis- Laplace transform and applications,Fourier series,Fourier Transform,two port networks
(With PSPICE Examples and a small intro about MATLAB

😁
Eddy boy • Nov 6, 2008
thanks ...
Fahad Bhatti • Nov 7, 2008
Eddy boy
In circuit analysis, what is the difference between voltage and current source ??current exits only when there is some potential difference then why we say only current source ?solve it!😕
well, a "source" means it has to maintain the parameter which it is source of, thus a voltage source has to maintain the voltage across its terminals regardless of the current through it ( for example if resistance is doubled in the circuit, current will be halved but voltage must remain same... V=IR )

a current source has to maintain the current through it regardless of the voltage across it ( for example if resistance is doubled, votage across its terminals will also be doubled but current through it will remain the same.... I= V/R )

got it brother?
Eddy boy • Nov 8, 2008
Is a battery is a voltage source? if yes then how ? it does not maintain voltage across its terminals when load resistance is altered...please give example of voltage source if any?
reachrkata • Nov 8, 2008
You got it wrong, in fact the opposite.
A battery is indeed a voltage source. Assuming it is well charged, it maintains the same voltage irrespective of the load.

Regarding a current source, I would say it is usually used as tool for circuit analysis. Though we can build circuits that act as a constant current source, we don't have a device (like a battery) that is a current source.

-Karthik
Aoedogg • Nov 12, 2008
Eddy boy
Is a battery is a voltage source? if yes then how ? it does not maintain voltage across its terminals when load resistance is altered...please give example of voltage source if any?
In general we would assume an ideal source, this means that it would be able to maintain a constant voltage/current regardless of the load.

In reality because of internal resistances, this is not possible. Generally in circuit analysis you would assume an ideal source, you should be aware of the deviation however.

To answer your question, assuming an ideal source, a battery would generally be considered a voltage source.
Eddy boy • Nov 12, 2008
ok thanks.
but buddy batteries are measured in Ampere/hour,so why they take current into consideratiuon when it is a voltage source???
Eddy boy • Nov 12, 2008
Explain your question sauravgoswami.Current and voltage relation is like mother and son,you can never separate one from other.
Eddy boy • Nov 12, 2008
frnds are you agree ,batteries are voltage source??i will never agree let me explain you in circuit loading if the load resistance is less than battery internal resistance then how you prove batteries are voltage source.
hassan.buet07 • Nov 13, 2008
yes, battery is a ideal voltage source. But it is not an ideal voltage source. It has some internal resistance in series with the load resistance. Therefore a little voltage drop occurs across the internal resistance. hence with the alternation of load resistance voltage across the load also changes.
Fahad Bhatti • Nov 14, 2008
battery is a voltage source and ideally it must maintain the voltage across it, but practically it is not seen in poor batteries as they attenuate their voltage level when used extensively, this actually happens due to charge deposit on electrodes of the battery with time... thus if no deposit occurs in batteries (i.e. an ideal condition) , then batteries will not lose their voltage even if resistance is varied
Another good example of voltage source is Synchronous Generator, it does not vary its voltage with load but may vary the supply frequency