Charge Conservation - Hint of the Day
in [Design]
|
From: kevin93 on 20 Jul 2010 12:40 On Jul 20, 8:24 am, Jim Thompson <To-Email-Use-The-Envelope-I...(a)On-My- Web-Site.com> wrote: > Charge Conservation - Hint of the Day: > > How many Coulombs can a 1mH inductor charged to 1A deliver? > > ...Jim Thompson .... Anywhere between zero and infinity depending on the load - of course it can only deliver 1 Coulomb per second regardless of the load. kevin
From: John Devereux on 20 Jul 2010 12:49 Jim Thompson <To-Email-Use-The-Envelope-Icon(a)On-My-Web-Site.com> writes: > Charge Conservation - Hint of the Day: > > How many Coulombs can a 1mH inductor charged to 1A deliver? Hi Jim, I think it depends on your definitions, I think most would say it will start out "delivering" one Coulomb per second, I.e. that is what flows through an external circuit. The subsequent behaviour, and hence total number of Coulombs "delivered", depends on what it is actually connected to. The charge delivered would be unlimited for a superconducting shorted-out inductor, and would be infinitesimal if the inductor was open circuited. But in the "all charge is conserved" picture all the charge that exits one terminal gets returned to the other. So Zero. So which definition do you want to use? And then of course there is the secret Jim Thompson Interpretation of Electrical Circuits... :) -- John Devereux
From: Richard Henry on 20 Jul 2010 12:58 On Jul 20, 8:24 am, Jim Thompson <To-Email-Use-The-Envelope-I...(a)On-My- Web-Site.com> wrote: > Charge Conservation - Hint of the Day: > > How many Coulombs can a 1mH inductor charged to 1A deliver? Into what?
From: George Herold on 20 Jul 2010 14:06 On Jul 20, 12:49 pm, John Devereux <j...(a)devereux.me.uk> wrote: > Jim Thompson <To-Email-Use-The-Envelope-I...(a)On-My-Web-Site.com> writes: > > Charge Conservation - Hint of the Day: > > > How many Coulombs can a 1mH inductor charged to 1A deliver? > > Hi Jim, > > I think it depends on your definitions, > > I think most would say it will start out "delivering" one Coulomb per > second, I.e. that is what flows through an external circuit. The > subsequent behaviour, and hence total number of Coulombs "delivered", > depends on what it is actually connected to. The charge delivered would > be unlimited for a superconducting shorted-out inductor, and would be > infinitesimal if the inductor was open circuited. > > But in the "all charge is conserved" picture all the charge that exits > one terminal gets returned to the other. So Zero. Zero 'total' charge is my answer, unless the inductor has a few stray charges on it's surface. George H. > > So which definition do you want to use? > > And then of course there is the secret Jim Thompson Interpretation of > Electrical Circuits... :) > > -- > > John Devereux
From: Tim Wescott on 20 Jul 2010 14:35
On 07/20/2010 09:32 AM, Jim Thompson wrote: > On Tue, 20 Jul 2010 08:53:22 -0700, Tim Wescott<tim(a)seemywebsite.com> > wrote: > >> On 07/20/2010 08:24 AM, Jim Thompson wrote: >>> Charge Conservation - Hint of the Day: >>> >>> How many Coulombs can a 1mH inductor charged to 1A deliver? >> >> That's insufficient information, and I rather expect that you know it. > > No. It's provided to cause young bucks to do some thinking. Looks > like it didn't work with you :-( You did _not_ give enough information: if you don't know why you should respectfully ask -- or do some thinking yourself. I purposely remained mysterious because I didn't want to ruin your fun. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" was written for you. See details at http://www.wescottdesign.com/actfes/actfes.html |