TNPE

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About TNPE

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    Project Manager

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  • Engineering Field
    Electrical (Power)
  • License
    PE
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    Casio
  • Discipline
    Electrical

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  1. What Owism said. There's a mountain of info on that forum. That said, I self-studied cause I didn't see the need to spend money on a course that couldn't prepare me in the manner I could prepare myself (i.e. presentation, types of problems, methods for solving, etc.). As for me, the resources I used to prep for the exam, and subsequently used for the exam, are: NCEES practice exam NEC NESC Graffeo P. C. Sen Electric Machinery book (a hard book to follow and a bit of overkill for the level you're being tested on, due to it being heavily academic based, but does have some decent info) Chapman (power systems and machinery - this one is a must have IMHO. I used this and Graffeo almost exclusively, outside of the codes) Power electronics text from college GA Tech binder I borrowed from a friend that took the course You have to know yourself more than anything. You can have all the materials/courses at your disposal and still fail. You know yourself better than anyone else, so if you learn better in a classroom, take a course. If you're more motivated by self-study, then take that route. Most of all, know your references. I'm certain a large portion of those who fail on any given cycle do so due to inadequate familiarity with their references. And remember to breathe!! We have all sat in that testing center and know the feeling all too well! Good luck!
  2. Fortunately, I've already taken and passed the exam; but I prepared and studied vigorously. I found the exam to be a fair representation of the material outlined by NCEES. That's not to say it was easy, cause it wasn't, but it was about what I expected with regards to concepts and intuitive thought. The afternoon portion was almost explicity regurgitated from my references and pre-exam preparations. Call me lucky or clairvoyant, but it was a sight to behold when the afternoon section began. I couldn't believe it!!!
  3. Power electronics will be presented in some capacity on the test (re: outline on NCEES website). As for your second question, I don't have an answer for you as to why it was worked that way without having more info. Could be a mistake on their part...?
  4. The PE is not as ambiguous as the above situation. Yes, it will force you to use some intuition and make some assumptions, but it alleviates ambiguity to that extent. To be honest, the PE is more about concepts, concepts, concepts! Not how well do you integrate and "guess" what I'm exactly asking for (integral/differential calculus is covered on the FE -- no need for that here, but is fair game). This exam with punch you until you feel like biting its ear off, but concepts are much more heavily presented than pure analytics and mathematic applications. @BigWheel can attest to that, at least I would guess he can (I wasn't at this administration so I can't say with certainty what was presented, but from my administration and others before me, I have gathered the exam is almost always presented heavily on concepts). To be perfectly honest with you, while not giving too much away, I would advise you to spend a lot of time on motors and all applications associated with them (analytical and especially conceptual). That's as far as I'm willing to go with regards to the concepts. Good luck!
  5. Actually, on second thought, my initial approach may be incorrect. I'm inclined to think your approach may be the way to go.
  6. Pardon the typo in my previous post.... should read infinitesimal, not infitesimal. @BigWheel, the work was spot on and much more elaborate than I could show by manually entering via a phone. I've tried to attach pictures and clips before, but the files have been too large and I'm never in a mood to compress/reformat.
  7. Avogadro's number
  8. BigWheel wasn't exactly right... The integral should be: (1/T)S(sin(wt))dt --where S is the integral and evaluate this from 0 to pi. Inherently, it is evaluated over one half cycle, since a full cycle would yield an average of 0 (i.e same curve area above and below and it would reduce to 0). The average can be looked at as the infitesimal points along the curve (one half cycle) and divided by the period (pi). Let's evaluate sin(t)dt : -cos(t) evaluated from 0 to pi = 1+1=2 Put it all together and you have: 2/pi = 0.637 460(0.637)=293 Vavg This holds true for any pure sinusoid evaluated over one half cycle with period T (and given your firing angle of 0 degrees). Stop overthinking it. Look at a single phase and evaluate the avg. voltage for that phase. This would hold true for any phase, but best to stay with A phase since it is assumed to be at 0 degrees (and the given equation says as much), unlike B or C phase. Your approach with 460 is way off. You're thinking about line voltage, when what you are given is peak voltage of 1-phase. You are averaging the peak, not the line, RMS or any other value. An instantaneous equation of voltage or current should immediately tell you that you're dealing with a peak value, unless, of course, you are told otherwise. If that were the case, you should appropriately multiply by sqrt2 to get it in terms of peak. Also, another tidbit, the ratio of the RMS voltage to the average voltage for a pure sinsusoid is always 1.11. Analytically, this would be {(Vp/sqrt2)/(2Vp/pi)} or pi/(2*sqrt2).
  9. As @BigWheel said, the given expression is for one phase (call it A). The subsequent phases would be the same with an argument of (wt-120) and (wt-240/or+120), respectively. Remember, if you are asked for an average, you will almost always integrate. In some instances, integration may not be necessary, but I would complete the integral anyway to be certain. This test will pique your intuition and challenge real-life applications, but it will present and quiz your theoretical understanding of ideal circumstances. Solve the problem with what is given!
  10. Also, since the firing angle is at 0, the waveform is a purely sinusoidal input (it is not chopped at pi/6, as would be the case if it were at 30 degrees).
  11. I'll try to point you in the right direction: First, it is rectified, so we are taking an AC input and getting a DC output. The given equation is an instantaneous expression for the voltage, v(t), where 460 is the amplitude (peak) of the voltage waveform (no need to multiply/divide by sqrt2, it is already in terms of what is needed to solve). Hope this helps!
  12. Yep, agreed! I don't understand the "shock." If you're shocked after taking a course and struggling with the test, your approach was entirely insufficient. Having good materials and knowing how to use them, I would argue, is more valuable than any course money can buy.
  13. Seems everyone is focused on a course rather than focusing on what works for them. Personally, I did not take a formal course. I didn't want to spend the money, and also, no one knows me and my abilities better than I do. I will go on the record and say that no course will be a 100% lead pipe cinch guarantee for success on this exam, and if someone tells you that, I hope your BS filter is tuned! I can't speak from experience, but from what I've gathered, these courses are regurgitated material from session to session. This test is dynamic, not static. My first piece of advice to anyone taking the test would be, read the NCEES outline on their website and build your studying off it. Your weaknesses will become apparent, and from that point, you can adjust your study habits to mitigate/improve these weaknesses. The outline is clear and concise and will give you the topics that the next exam administration will cover. Will you see all of them? Who knows, but if it is on there, it is fair game. When I took the exam, I would guess that 95% of the material identified in the outline was on the exam. From my point of view, I don't believe any course could prepare me in the manner I could prepare myself. For a lot of reasons, but namely, I had to cover the material (I could go at my own pace, use different approaches, etc.), prepare my materials (no course will do this for you, and no manual/book/binder is an all-inclusive resource... plus, you need to know how to use these resources) and focus my mind and keep my nerves steady. Some may disagree entirely and feel that a course is the way to go, but I do not for the reasons indicated above. Just my , whatever that is worth. Good luck and don't let the wait kill you! We've all been there, and boy, does it suck harder than a Dyson, but it's done. Enjoy springtime and let the dice fall where they may. If you're unsuccessful, you will know where you were weakest and how to improve the next time.
  14. Cheaper on gas
  15. I told my wife that and....well... umm if looks could kill, I wouldn't be here telling you that.