# Kaplan Power PE Review Problems



## knight1fox3 (Apr 12, 2010)

Has anyone completed the Kaplan power PE review problems in the afternoon section and found the rectifier questions to be troubling? With all the good references I have, I haven't been able to find a good resource for single-phase, three-phase, and SCR (thyristor) type recitifier circuits. There is some useful information in a Micro-electric circuits (by Sedra &amp; Smith) book I have but doesn't quite hit on the what the Kaplan book is asking. Any tips or thoughts on this? Thanks in advance.


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## pelaw (Apr 12, 2010)

I am not using the Kaplan prep materials. Is this for the power exam? What is the nature of the problems? Do they ask you to calculate ripple voltages, or anything detailed about the circuit's behavior?


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## knight1fox3 (Apr 12, 2010)

pelaw said:


> I am not using the Kaplan prep materials. Is this for the power exam? What is the nature of the problems? Do they ask you to calculate ripple voltages, or anything detailed about the circuit's behavior?


Yes for the power exam. I don't have the book with me at the moment but will post back with a few of the problems I am referring to. The problems may indeed be very basic but my undergrad. program didn't go into much detail on different types of rectifier circuits. Mainly just the very basic half and full-wave rectifiers, nothing on calculations for a rectifier circuit under different loads. And I have little to no reference materials on rectifier circuits that utilize thyristors.


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## pelaw (Apr 12, 2010)

Here is an excellent web site that explains the solid state controls without going to much into calculations. I think it will suffice. http://www.allaboutcircuits.com/vol_3/index.html


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## knight1fox3 (Apr 12, 2010)

knight1fox3 said:


> pelaw said:
> 
> 
> > I am not using the Kaplan prep materials. Is this for the power exam? What is the nature of the problems? Do they ask you to calculate ripple voltages, or anything detailed about the circuit's behavior?
> ...


See attached images. And thanks for the link, I briefly looked at it and saw general rectifier information but nothing with thyristors.


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## pelaw (Apr 13, 2010)

Problem 34 is hard. I did some research and there are not clear answers. None of this is in the Sedra book either. Therefore I hope that question does not come up since it is heavy duty electronics. I'd circle 25. 

Pr. 35. Half wave rectifier. Each diode conducts for half the 120.

Problem 32. Gotta be D. Alpha affects the current, and load voltage in inverse way. Vmax is 2 pi. Thyristors conduct full wave.

Pr. 33. Full wave rectifier. Period at load is 1/2 of supply. f = 1/T =&gt; f = 2/T so fg= 2fs.

I think. Again, I 've not done any electronics engineering, and I hope not to see any on the exam.


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## knight1fox3 (Apr 13, 2010)

pelaw said:


> Problem 34 is hard. I did some research and there are not clear answers. None of this is in the Sedra book either. Therefore I hope that question does not come up since it is heavy duty electronics. I'd circle 25.
> Pr. 35. Half wave rectifier. Each diode conducts for half the 120.
> 
> Problem 32. Gotta be D. Alpha affects the current, and load voltage in inverse way. Vmax is 2 pi. Thyristors conduct full wave.
> ...


Thanks for the feedback pelaw. That is good to know that you as well found these problems to be somewhat difficult. I was not able to find information in the Sedra book either on these types of problems. I am also hoping these in-depth types of rectifier problems will not appear on the exam. For the power PE exam specifications, I did not see rectifiers listed as a main topic so hopefully any questions dealing with them will be basic.

Ans for Probs listed above: 32 b, 33 a, 34 a, 35 d


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## pelaw (Apr 13, 2010)

Thanks :-((

That really give me confidence! I know nothing :- )


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## knight1fox3 (Apr 13, 2010)

pelaw said:


> Thanks :-(( That really give me confidence! I know nothing :- )


Sorry, didn't intend to make it sound that way. And by reading some of your previous posts, you knowing nothing is certainly not true.


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## pelaw (Apr 13, 2010)

jk. Thanks for posting. There is no way I can get prepared for electronics questions on the exam.


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