# Search results for query: *

1. ### Thevenin reduction of network for fault analysis trouble.

tra Transformation right enough, thanks for this.
2. ### Thevenin reduction of network for fault analysis trouble.

Yes, thanks will try again with this in mind. thank you
3. ### Thevenin reduction of network for fault analysis trouble.

I have just realized i have not converted from cart to pol when calculating equivalent impedance. doh, i think this may have been the problem
4. ### Thevenin reduction of network for fault analysis trouble.

Homework Statement Reduction from top network to bottom network in the screen shot. I can not find the steps that have been taken to do this. Fault impedance = Zfa = Zfb = Zfc = j0.5 Homework Equations The Attempt at a Solution in hand written screenshot, sorry for the mess, just to show...
5. ### I Capacitive reactance

Hi Folks, I am reading some text about capacitive reactance that reads 'so we know that capacitors oppose changes in voltage' would this be the supply voltage or the voltage in the capacitor? I am struggling to see how the change is opposed surely the quoted statement would infer increasing...
6. ### Simplifying a fraction (block reduction, control)

Just rusty on the syplifying. Thanks
7. ### Simplifying a fraction (block reduction, control)

Thats fantastic BvU, once again crystal clear,
8. ### Simplifying a fraction (block reduction, control)

Ok fair enough.
9. ### Simplifying a fraction (block reduction, control)

-- Please if you have the time BvU can you help me fill in the step in the attached. Sorry that should also read C(S)/R(S) = Thanks
10. ### Simplifying a fraction (block reduction, control)

Crystal clear, thanks very much BvU.
11. ### Simplifying a fraction (block reduction, control)

yes I have since noticed this, thanks. Appreciated
12. ### Simplifying a fraction (block reduction, control)

I was thinking why two of the 4's come out on the bottom line and only one on the top. Is this because the two 4's on the bottom line are from different expresions?

2 obviously
14. ### Simplifying a fraction (block reduction, control)

Homework Statement 2*3*4*5/4+3*4*4*6 Homework Equations 2*3*4*5/4+3*4*4*6 The Attempt at a Solution 2*3*5/1+3*4*6 Knowledge gap 1 - I do not understand why if top and bottom are divided through by 4 there should be a 4 left in the denominator and why the rest of the numerators and...
15. ### Simple series capacitor

Thanks for that Jim, good read.
16. ### Simple series capacitor

Fantastic responses, thank you so much. Think I've got it just going to do some further reading of the back of your information. Thanks again
17. ### Simple series capacitor

Hi folks, Just looking for an explanation on capacitor principles. My understanding: A capacitor is made from two conductors ( which have the ability to hold charge) separated by an insulator. Therefore current cannot flow between the+ and - plates. Unless unwanted breakdown from excessive...
18. ### 3 phase bridge uncontrolled rectifier, resultant waveform

Thanks for the ripple calc, useful and explained well.

Attachment
20. ### 3 phase bridge uncontrolled rectifier, resultant waveform

I will have to double check the book but it's back in the library just now but from memory the resultant voltage at the load is the difference between the line voltage and the phase voltage that would appear at the top of the load. I have annotated a chopped page from that book, please see...
21. ### 3 phase bridge uncontrolled rectifier, resultant waveform

Diagram is right.
22. ### 3 phase bridge uncontrolled rectifier, resultant waveform

Thanks for your opinion, these were my initial thoughts but I thought the book couldn't be wrong.
23. ### 3 phase bridge uncontrolled rectifier, resultant waveform

I think this might be the answer I'm looking for. Need to do the sums to prove I think
24. ### 3 phase bridge uncontrolled rectifier, resultant waveform

What I don't understand is why the rectified waveform does not have the positive voltage peaks (a b c) occurring at the same phase angle as the original 3 phase positive voltages This is also happening with the flipped negative voltages. Pointed out with the dotted lines in the image above.
25. ### 3 phase bridge uncontrolled rectifier, resultant waveform

Hi all, Having difficulty understanding the above resultant wave form, been looking at power electronics (C.W.Lander) but don't quite get the addition of the wave forms (positive and negative cycles)can anyone point me to some reading of theory I am missing for this, thanks.

27. ### Basic electricity

Hi Folks, Didn't know what other thread to ask this on. I have an electrical power eng book which keeps referring to negative current with respect to thyristors. Am I missing something here, is there such a thing. Current always flows from high to low potential. So if your terminal voltage is...
28. ### Snubber circuit types

Perfect,thank you Svein
29. ### Snubber circuit types

Hi folks, another Q on snubber circuits. Are they the same as freewheeling diode?
30. ### Need help understanding inductors

Smashing thanks for clearing that up. I don't like to leave things to assumption.

eg.
32. ### Need help understanding inductors

Thanks for the reply NascentOxygen, So If the windings are touching in an Inductor, transformer, motor/generator etc they will always have a form of insulation? What has thrown me is that in some pictures of the components stated it looks like there is no insulation, but from your reply I...
33. ### Need help understanding inductors

Hi All, Silly question here I'm sure. But. Why does current not travel the shortest distance across an inductive coil (if the coils are physically touching and not insulated) instead of all the way through the coil. Any insight. Thanks.
34. ### Energy network Earthing

Sorry for the late reply, but thanks for all the replies much appreciated, although maybe created more questions, thanks all
35. ### Energy network Earthing

Hi All, First post of many on the forum. On the Subject of earthing I had always been led to believe that electricity would always go to ground (if of course ground was the lower potential) I was talking to someone the other day who was discussing un-earthed transmission systems and live...