# Search results

1. ### Why should one use convolution ?

hi mike i am really new to dsp and control systems etc.and there is actually no one who can sit down and explain all this stuff to me.So u see its more of a self study.I am much dependent on the forum and replies from people like you. i shall see if i can get hold the book u mentioned.I am...
2. ### Why should one use convolution ?

hi berkeman Thanku for the response.I am actually learning control systems now and came across this DSP stuff in it. As far as i know DSP is way too hifi to begin in this priliminary stage.Is it not?So i tot i wud stick with understanding Control systems then move on to DSP.I have heard its...
3. ### Why should one use convolution ?

hello Why shud one use convolution ?Inorder to get the state transition matrix from x'=Ax+Bu x(t)=exp(at)x(0) + integral[exp(a(t-tau)) bu(tau) dtau where tau is the variable of convolution. i have read that convolution is used when integration is reqd,for instance,in capacitors and...
4. ### 3 phase power

thanx a lot russ,i really needed this. :smile:
5. ### 3 phase power

hey dlgoff thanx a lot.i shall look into each link and hopefully find what i am loking for and more. Thanx a loooooot!!!

hi es that is a very useful bit of info.I really needed it.Thanx for the same. :smile:
7. ### 3 phase power

Hi all, 3 phase power is measured using 2 and 3 wattmeter methods.Correct? can someone explain how these 2 work?I cudn get enuf info on it.

hi, Can someone suggest some good books in Control Systems engg. which includes all from laplace to bode plots,nyquist etc etc. Thanx for any help.
9. ### Q is the quality factor of series resonant circuits

Can someone tell me how to find the Quality factor of a loaded resonant circuit? PLEASEEEEEEEEEEthanks a lot.
10. ### Q is the quality factor of series resonant circuits

i am sorry to be a dumbo but i wish u spelled it out. :redface:
11. ### Q is the quality factor of series resonant circuits

Hi all I read that Q,the quality factor of series resonant circuits is wL/R ------------>1/R sqrt(L/C).This i understand 1.but for parallel resonant it is R/wL....hmm but why is that?this i don quite get. 2.Then what do u mean by loaded resonant circuit and unloaded resonant circuit...
12. ### Parallel RL circuit

okay sgt,now i get it. thanx a loooooooooooooot!
13. ### Parallel RL circuit

but then sgt,i also read that ip shud be assumed as acos(wt+phi) + bsin(wt+phi) not Kcos(wt+phi) as the supply is Vcos(wt+phi).they need not be in phase... i am confused now.
14. ### Parallel RL circuit

SGT,Thankyou very much indeed. I think i got the stuff in my head atlast. Thankyou. :smile:
15. ### Parallel RL circuit

how u get the steady state and coomplementary solution. i understood quite a few things from ur replies but not how to reach the final equations.i am going wrong whenever i try it. so cud u please help out?thanku again
16. ### Parallel RL circuit

I am sorry but I donno how to go abt with the equations.
17. ### AC Electrical Theory

hey astronuc,thanx a looooooooooot! :smile:
18. ### Parallel RL circuit

V=Acos(wt+phi)=Acoswt+Bsinwt L d^2i/dt +Rdi/dt +i/C=dV/dt i=A1exp(s1t)+A2exp(s2t) di/dt=s1A1exp(s1t)+s2A2exp(s2t) d^2i/dt^2= s1^2A1exp(s1t)+s2^2A2exp(s2t) i(0)=V/R if its dc dV/dt=0 ac then dV/dt=-Awsinwt+wBcoswt is this going wrong?
19. ### Parallel RL circuit

yes,but how to find the values of A1 and A2?
20. ### Parallel RL circuit

thanx for the quick response. For example, The overdamped case has the solution v=A1exp(s1t)+A2exp(s2t) and the equation is of the form series rlc L d^2i/dt +Rdi/dt +i/C=dV/dt cud u please help me?
21. ### Parallel RL circuit

okay i understand. Is this used in second order equations as well? hmm.... an underdamped case for instance there r two coefficients in it right? how is that found? i hope i am notgetting onto ur nerves! thankyou for all the help.
22. ### Parallel RL circuit

:biggrin: just one more question... why cant it be Acoswt?why the phi? why shud it be coswt?why not sinwt? (am i being really stupid? :rolleyes: )
23. ### Parallel RL circuit

:smile: SGT...thanx a million. i hope i am right this time.... -L(Awsinwt+Bwcoswt)+R(Acoswt+Bsinwt)=RIcoswt (-LBw+RA)coswt=RIcoswt -LBw+RA=RI -LAw+RB=0 solve this to get A and B w=2 pi f this approach is used for second order also right? thankyou once again!!! :approve:
24. ### Parallel RL circuit

SGT,Thanx again ALOT!!! So, for particular solution i assume i=Acoswt putting in first eqn Ldi/dt+Ri=RIcoswt -Lwsinwt+RAcoswt=RIcoswt equating the coefficients on LHS and RHS looks like i am going wrong...is it? please help.
25. ### Parallel RL circuit

Okay i get it.thanx SGT. but ...heheh :biggrin: how do u find the value of A?
26. ### Parallel RL circuit

Thankyou corneo, Okay so i get Ldi/dt+Ri=RIcoswt to get the complementary solution assume Ldi/dt+Ri=0 int di/i=- intR/L dt ln i= -R/Lt+K i=exp(-t/tau+k) at t=0 initial condition i is V/R then its..?is it right? for particular solution i assume i=Acoswt putting in...
27. ### Parallel RL circuit

thanx for the reply, corneo hmm... okay.but i was wondering why shud i assume the solution Acos(wt+Phi)? Is this what is assumed for first order circuits subject to ac supply?i read its Acoswt+Bsinwt for second order circuits.am i right? :confused:
28. ### Solving natural/step response in RL/C circuits

astronuc,isnt natural response called transient response as well? ng
29. ### Parallel RL circuit

hey sgt,thankyou for that reply.yeah,how stupid of me.....u r right. thanx again.
30. ### Parallel RL circuit

Thanx for the response.I have already seen that and din help me much. The problem is with getting the transient solution. RC parallel -If the input is Vcoswt then current throu R will be V/Rcoswt.throu C is -CwV sinwtThis is te steady state i understand.But the transient and getting to it...