Lecture 17: Inverters, Part 1

Comments · 27

• LU

  @luisjalabert8366 · 2 years ago

  This is so good... This teacher is amazing

  14

• QU

  @quetzal4042 · 2 years ago

  Ha!  I always assumed they were called inverters because they periodically "invert" the voltage.  Great teacher.  I used to do a good bit of teaching myself so I know how much more work it is to prepare a chalk-talk lecture than to just use slides like most people do - but it is also much more effective.

  8

• RO

  @robertpearson8546 · 6 months ago

  How about a VRM? AC/AC 3 phase.

• DO

  @dougli1sqrd · 1 year ago

  At <a href="https://www.youtube.com/watch?v=So_UGo4dSJs&amp;t=2692">44:52</a> the instructor is talking about making sure your mosfets aren&apos;t switching at the same time, but that we don&apos;t want to &quot;open circuit&quot; the load (esp if there&apos;s an inductive load). But he says that we first turn off S1, and if the inductor current is positive, then that current still has to flow somewhere: &quot;but [the current] can just commutate from S1 into [S3&apos;s body] diode&quot;. Then once the body diode in S3 turns on we can turn on the S3 mosfet. But I don&apos;t understand what he means when he says the current will &quot;commutate&quot; into S3&apos;s diode, nor do I understand why the diode of S3 would eventually turn on when <b>only</b> S2 is on. Would the node between S3 and S1 (the + of the load) become negative relative to DC ground, turning on that diode? If so, why? Thanks for any insight anyone has!

  2

• RO

  @RohitNandan-u4n · 11 months ago

  <a href="https://www.youtube.com/watch?v=So_UGo4dSJs&amp;t=286">4:46</a> Shouldn&apos;t sine (wt) have period T &amp; and not T/2?

  1

• GA

  @gabrielschossler6072 · 1 year ago

  Just one thing, at 970, with S1 and S4 on, we also get Vdc (but the current is 0 of course) or am i missing something?

• TH

  @thomasgeorget · 1 year ago

  What happens if I use IGBT with and without antiparallel diodes in a CSI ?

  1

• WI

  @wineetbhatia · 2 years ago

  What is KPVS?

  3

• MA

  @martf1061 · 2 years ago

  I&apos;m a simple electrician that connected many motors in the past 25 years, and VFD&apos;s are relatively recent in the field.<br>When i started working, i think the most common method used to vary speed of motors, was with variable resistance.<br>Now, it&apos;s all about VFD&apos;s..<br>60hzAC to pulseModulatedDC, &nbsp;and finally &quot;fake AC&quot; applied to the motor.<br>Is it an efficiency purpose, or something else..?

• DR

  @Dr-Satch · 3 months ago

  Dear Mr. Perreault, <br>allthrough I do understand about the Fourier part, <br>doesn&apos;t a &apos;perfect&apos; sine exists of infinite odd harmonics ? <br>So why filtering them as much out, to get only a first fundamental sine wave form shape ? <br>Are all those mentioned harmonics than unwanterd side effects, of generating a sine ? <br>Or is it just to make the filtering of the fundamental only easier ? <br>Best regards, Harry.

• MA

  @martf1061 · 2 years ago

  <a href="https://www.youtube.com/watch?v=So_UGo4dSJs&amp;t=419">6:59</a><br>... No questions..?!? 🤨🤨 <br>That&apos;s Odd..

  1