From winton at ece.msstate.edu Thu Sep 13 14:19:43 2007 From: winton at ece.msstate.edu (Raymond S. Winton) Date: Thu Sep 13 13:22:26 2007 Subject: [ece3283] hw2a Message-ID: <46E98D4F.6010608@ece.msstate.edu> Please turn-in (for the second time) your hw2a. Seems that among my other sins I managed to neglect (1) to record the scores for that homework and (2) award the 5% bonus. -RW -------------------- From winton at ece.msstate.edu Tue Sep 18 16:36:57 2007 From: winton at ece.msstate.edu (Raymond S. Winton) Date: Tue Sep 18 15:40:30 2007 Subject: [ece3283] Re: Hw4 # 10-7 In-Reply-To: <1E.EE.05902.109EFE64@mxo5.broadbandsupport.net> References: <1E.EE.05902.109EFE64@mxo5.broadbandsupport.net> Message-ID: <46F044F9.7000008@ece.msstate.edu> Egad. It must have been inserted by space aliens. Delete problem 10-7. Schedule also has (should have) been corrected. -RW ------------------------- Peter Ireland wrote: > > Thanks for your help. On the schedule I?m looking at, 10-7 is the > last problem assigned for hw4. Should we omit this problem from the > hw set then? > > > > Thanks, > > Peter > > > > ------------------------------------------------------------------------ > > *From:* Raymond S. Winton [mailto:winton@ece.msstate.edu] > *Sent:* Tuesday, September 18, 2007 10:50 AM > *To:* Peter Ireland > *Subject:* Re: Hw4 # 10-7 > > > > > Exercise 10-7 is not likely for any of your assignments because it > makes use of the ideal diode equation (which is a little over-the-top > for a survey course). > > But since you asked, you use the ideal diode equation to find IS, > which is proportional to area, for which a power diode would have > large area, and consequently large IS (on the order of 10^-9 A). > > If you put two diodes in parallel, each one carries half as much > current. And the voltage across them drops slightly. You can find > out this voltage by using the IS that you found for the diode and > inverting the ideal diode equation. > > Since VT relates entirely to thermal equilibrium, it is same for any > diode. > > The slight change in voltage would give a slight change in the current > through the resistance. > > And after you have done all of this you will end up with a result that > is close to that you obtained using the assumption of VD approx 0.7V. > > The advantage of putting two diodes in parallel is that they each now > use only half as much power (ID x VD) as a single diode. Increases > the survivability. > > -RW > > ------------------- > > > > Peter Ireland wrote: > > I came across a question on problem 10-7 of the homework. You are > given a value of 1.0A at 0.7V for a 1.0A power diode. From this > voltage and current, should you solve for V_T assuming a temperature > of 300K and an I_s value of 10^-14 A, and use this same V_T value in > later calculations, or should you use a standard value for V_T (.026V) > and I_s (10^-14 A)? You are also given a current of 0.5A though the > diode before another diode is placed in parallel. Can you assume a > constant current though the diode and the resistor, and thus obtain > the value of the voltage across the diode independently from the > Shockley equation? > > > > Thanks for your help, > > Peter > > > > No virus found in this outgoing message. > Checked by AVG Free Edition. > Version: 7.5.487 / Virus Database: 269.13.21/1012 - Release Date: > 9/16/2007 6:32 PM > > > > > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.5.487 / Virus Database: 269.13.22/1013 - Release Date: > 9/17/2007 1:29 PM > > > No virus found in this outgoing message. > Checked by AVG Free Edition. > Version: 7.5.487 / Virus Database: 269.13.22/1013 - Release Date: > 9/17/2007 1:29 PM > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.ece.msstate.edu/pipermail/ece3283/attachments/20070918/edd7bcb8/attachment.html From winton at ece.msstate.edu Thu Sep 27 14:01:49 2007 From: winton at ece.msstate.edu (Raymond S. Winton) Date: Thu Sep 27 13:05:02 2007 Subject: [ece3283] Re: Transfer Curves In-Reply-To: References: Message-ID: <46FBFE1D.8050504@ece.msstate.edu> You do not. Did not give transfer curves any class coverage this semester. Regrets. -RW ---------------------- Peter Ireland wrote: > > Dr. Winton, > > > > Do we need to be able to construct transfer curves as described in HW6 > problems 10-14 and 10-17? > > > > Thanks, > > Peter > > > No virus found in this outgoing message. > Checked by AVG Free Edition. > Version: 7.5.488 / Virus Database: 269.13.32/1033 - Release Date: > 9/27/2007 11:06 AM > -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.ece.msstate.edu/pipermail/ece3283/attachments/20070927/2cf07df1/attachment.html From winton at ece.msstate.edu Thu Sep 27 19:19:56 2007 From: winton at ece.msstate.edu (Raymond S. Winton) Date: Thu Sep 27 18:23:09 2007 Subject: [ece3283] Your HW#5 is in my doorbox Message-ID: <46FC48AC.2090300@ece.msstate.edu> And the solutions (and others) are posted under the URL http://www.ece.msstate.edu/~winton/classes/ece3283/solutions/ -RW -----------------------