# Power Electronics: power converter

I have been running through example questions for an exam I have coming up; the following picture is a condensed version of half a page of working.

My lecturer gave us the solutions and a few steps between beginning and end to get to the solution so we could work it out. However, as you can see the picture below I got 30.6A whereas she wrote 54.2 down.

The problem is to "Find the maximum values of the average" (done this bit) "and rms thyristor currents for any firing angle, alpha.". The values of R and Vs are in the diagram. Alpha is assumed to be 0 since then the thyristors will conduct for the greatest possible length of time.

I think she may have got to the end then forgotten to square root of Pi before multiplying Vm/2PiR by it. Does anyone agree?

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Jun 4, 2010. 6:55 AMsteveastrouk says:
So NOT for any alpha (stupid editor doesn't do Greek), but the specific case when alpha= 0 ?
Jun 4, 2010. 7:08 AMsteveastrouk says:
Hang on a minute, if you're in full conduction, isn't it just Irms= Vrms/3 m= 76 A ?
Jun 4, 2010. 10:03 AMkelseymh says:
Geez, guys. Do you really have to do office hours online?!?
Jun 5, 2010. 7:41 AMsteveastrouk says:
I'm still teaching him, not employing him. Turns out his lecturer can't do math(s). Steve
Jun 5, 2010. 1:08 PMkelseymh says:
:-) You do know I was just rattling your cage, right? :-D This was an excellent Question for James to post, but you guys got it all resolved before I could even Feature it...
Jun 5, 2010. 2:07 PMsteveastrouk says:
Of course I do- like I said, it transpires that the worked example his lecturer had set didn't work - James worked it and hadn't seen the limiting case, which was asked for, and just means I=V/R !
Jun 4, 2010. 2:35 PMkelseymh says:
I just tested this explicitly by creating a question, then going back to [Edit question]. It worked fine for me (MacOSX 10.5.8, FF 3.6.3), putting my original text into the edit box. If you're able to reproduce it, would you mind posting a bug report?
Jun 4, 2010. 11:10 AMkelseymh says:
I just tested the  capability on one of my recently posted forum topics. It did put the original text into the editor box and let me modify/add to it. Perhpas you were caught in a rollout glitch?